How to make concrete pillars for the foundation. Do-it-yourself columnar foundation: step-by-step instructions. Conventional pile and support-column foundations

In the article we will look at the columnar foundation of a house and describe the columnar strip foundation (column foundation with a grillage). We will tell you in what cases the construction of a columnar foundation is most applicable. The structure of a columnar foundation, recommendations and errors when installing a columnar foundation are described in separate parts.

General information about columnar foundations.

The preparation stages and manufacturing technology for a columnar foundation and a strip foundation are in many ways similar. Therefore, it is not advisable to repeat the general provisions characteristic for the manufacture of foundations (assessment of soils, freezing depth, presence of groundwater and communications, preparatory work, installation of formwork, pouring concrete, possible errors during design and construction) in this article. To get acquainted with them, just refer to the article.

Along with an overview of all options for columnar foundations, we will focus on foundations made from prefabricated concrete and reinforced concrete blocks.

A columnar foundation is a system of pillars located in the corners and at the intersections of walls, as well as under heavy and load-bearing partitions, beams and other places of concentrated load of the building. To create conditions for the pillars to work together as a single structure and to increase the stability of columnar foundations, to avoid their horizontal displacement and overturning, as well as to arrange the supporting part of the base between the pillars, a grillage (tied beams, rand beams) is made.

The main type of columnar foundations used in mass construction are monolithic reinforced concrete foundations.

As a rule, the distance between the pillars is 1.5-2.5 m, but it can be more.

With a distance between pillars of 1.5-2.5 m. The grillage is an ordinary reinforced lintel. At the same time, it is impossible to combine an attached terrace, veranda, or porch into a single constructive solution. These rooms must have their own foundation, that is, they must be separated by an expansion joint, since the load from the porch is not comparable to the load from the walls of the house, and accordingly their settlement will be different.

You can read more about the design of such a seam in the topic .

When the distance between the foundation pillars is more than 2.5-3 m, the grillage is made from a more powerful, so-called rand beam. The rand beam is made in the form of a monolithic or prefabricated reinforced concrete beam. It can also be metal (I-beam, channel, profile).

for houses without basements with light walls (wooden, panel, frame);
under brick walls, when a deep foundation is required (1.6-2.0 meters, i.e. 20-30 cm below the depth of seasonal soil freezing) and a strip foundation is uneconomical;
when the soils during the operation of the building ensure that the settlement of the columnar foundation (at equal pressures of the pillars on the ground) is significantly less than that of a strip foundation;
when it is necessary to eliminate as much as possible the negative impact of frost heaving on the foundation, because columnar foundations are less susceptible to this phenomenon.

a - prefabricated-monolithic when the groundwater is located at the time of work below the base of the foundations;

b - prefabricated for any location of groundwater;

1. prefabricated reinforced concrete support column with a rod reinforcement cage;

2. the same, with a steel pipe core;

3. the same, with a rod reinforcement frame and a shell made of asbestos-cement pipe;

4. the same, with a core made of steel pipe and a shell made of asbestos-cement pipe;

5. Prefabricated steel pipe support pole;

6. backfilling with excavated soil;

7. base plate made of monolithic reinforced concrete;

8. base plate of prefabricated reinforced concrete foundation;

9. sand cushion.

Let's consider several points in favor of using a columnar foundation:

If the cost of other types of foundations is 15-30% of the cost of the entire house, then the cost of a columnar foundation will be no more than 15-18%.
Columnar foundations are 1.5-2 times more economical than strip foundations in terms of material consumption and labor costs.
Columnar foundations have another positive quality, which is that the foundation soils under free-standing supports work better than under solid strip foundations, as a result of which the settlement under them at equal pressures on the ground is much less than that of strip foundations. Reducing the amount of settlement makes it possible to correspondingly increase the pressure on the ground by 20-25% and, consequently, reduce the total area of the foundation.
The most dangerous forces acting on the foundation of low-rise individual houses are the forces of frost heaving. Therefore, almost all of the given options for constructing foundations are considered from the point of view of their construction on heaving soils. It is generally accepted that when building on heaving soils, the depth of foundations should be lower than the calculated depth of seasonal freezing. However, for lightly loaded foundations of small houses, heaving forces usually exceed the total load from the house acting on the foundation, as a result of which various types of deformations occur.

Therefore, when building houses without basements on heaving soils, it is better to build shallow or non-buried foundations. Let us explain their differences.

Shallow foundations with a laying depth of 0.5-0.7 standard freezing depth are considered. For example, with a standard freezing depth of 140 cm, the depth of a shallow foundation will be 140x0.5 = 70 cm.
Non-buried foundations- foundations are considered to be those whose laying depth is 40-50 cm, and is on average half or a third of the freezing depth.

For large freezing depths in heaving soils, anchor columnar reinforced concrete monolithic or prefabricated foundations are effective. Such foundations are insignificantly affected by frost heaving forces acting on the side surface, since the pillars are made with a minimum cross-section. If the foundation is built from stone, brick, small blocks, or monolithic concrete without reinforcement, its walls must be made tapering upward, this will save material and evenly distribute the load from the walls.

Additional measures to reduce the influence of frost heaving forces can be: covering the side surfaces of the foundation with materials that reduce soil friction, such materials are bitumen mastic, plastic lubricants (synthetic grease “S”, CIATIM-201, BAM-3, BAM-4), organosilicon compounds , epoxy resins, furan-epoxy composition, polymer films, as well as insulation of the surface layer of soil around the foundation. The feasibility and options for such insulation are outlined in the question.

Conditions under which columnar foundations are not recommended:

in horizontally moving soils and soft soils, since their design is characterized by insufficient resistance to overturning. To absorb lateral shear, a rigid reinforced concrete grillage is required (its installation will negate the cost savings on the difference between columnar and strip).
Their use is limited on weak-bearing soils (peat, subsidence rocks, water-saturated clay, etc.) and in the construction of houses with heavy walls (massive brick with a thickness of more than 510 mm, standard reinforced concrete slabs and blocks);
If you have limited financial capabilities or time period for installing a plinth. If with a strip foundation the base is formed as if by itself, then with a columnar foundation, filling the space between the pillars with a wall (taking in) is a complex and time-consuming task;
It is not recommended to install columnar foundations in areas with a sharp difference in heights (the height difference in the area under the foundation is 2.0 m or more).

Let's consider what materials a slab foundation can be made of, depending on the design of the house (primarily its mass and number of storeys):

The stone foundation is made from rubble stone or medium-sized flagstone. It is advisable to select a stone of the same size, and the flatter it is, the better.
It is advisable to make brick foundations from well-burnt red brick (black), preferably iron ore. Poorly fired bricks quickly collapse.
Concrete foundations are made of heavy concrete grades B15-B25;
Rubble concrete;
Monolithic reinforced concrete (a monolithic foundation has increased strength and has the longest service life - up to 150 years);
Ready-made prefabricated concrete and reinforced concrete blocks. In the prefabricated version, the poles are manufactured separately and mounted during installation.
asbestos-cement or metal pipes filled with concrete mixture.

concrete and rubble concrete - 400 mm;
masonry - 600 mm;
brickwork above ground level - 380 mm, and when tied with a pick-up - 250 mm;
from rubble - 400 mm;

Photo of a columnar foundation for a small private (country) house.

Information about the depth of laying columnar foundation supports

It is necessary to pay attention to three main points when determining the depth of laying a columnar foundation:

the depth of soil freezing in your area where the house is being built; (The best option is to lay the pillars below the freezing depth of the soil, thus eliminating deformation of the foundation)..
determination of the type and composition of the soil (fixed soil or mobile, clay or sandy. The best soil can be sand, since water drains through it instantly and it has a high load-bearing capacity; it is impossible to build on silty and peat soils, it is necessary to arrange partial or complete replacement of the soil to sandy);
groundwater level (is there a pond or river nearby, if there is this indicates the presence of a high groundwater level, it is necessary to do waterproofing or drainage)

These factors must be taken into account in the house project you order.

Also, when calculating the foundation depth, the designer should take into account not only natural influences on the foundation, but also the following indicators:

the weight of the future house;
weight of foundation supports;
the weight of the furniture in the house and the number of people who will live in this house;
seasonal, temporary loads (snow).

It is advisable to contact a designer who has all the necessary data to carry out such calculations (groundwater level in your area, freezing depth, soil structure, etc.). The value of the designer's participation in the design process is that he will calculate the depth of the foundation with absolute accuracy (without excess depth margin). This will allow you to save on building materials and financial resources without compromising the quality and safety of your home.

Construction of a columnar foundation

In this section we will look at the technology for constructing a monolithic reinforced concrete columnar foundation as the most common type in private construction.

1. Preparatory work

Work must begin with cleaning the construction site. To do this, it is necessary to cut off the vegetation layer, preferably at least 2.0-5.0 meters in each direction from the planned location of the foundation. Its thickness is 10-30 cm, and it is not suitable for the base of the foundation. This soil needs to be cut and transferred to the vegetable garden or garden.

If the soil under the cut layer consists of sand mixed with small stones (gravel sand, coarse or medium-grained sand), then it is used as the base of the foundation, regardless of humidity, groundwater level or freezing depth.

If there are clayey soils (clays, loams, sandy loams), then a sand-gravel cushion must be installed. The thickness of the cushion depends on the geological characteristics of the soil.

If you find peat or silty soils under the cut layer, then it is necessary to completely replace the base; in this case, you need to consult a geologist on the composition and design of the artificial base.

Garbage and all foreign objects are removed from the construction site.

After the construction site has been cleared, it is leveled. The mounds are removed and soil is poured into the existing holes. Control of the horizontality of the area is carried out with a level, which is installed on a 2-2.5 meter flat board or rail. Preparation ends with the delivery and storage of building materials to the site.

2. Foundation breakdown

The breakdown of the house plan on the site consists of transferring from the drawings to the land plot and fixing the axes and main dimensions of the foundation.

Before laying out the foundation of the house, pillars (cast-offs) are installed along its perimeter, at a distance of 1-2 m from the building. Wooden boards or slats are nailed level to the pillars on the side of the future walls of the house and parallel to them, on which the dimensions of individual parts of the pit (trenches and holes) and the foundation itself and future walls are marked. The accuracy of the center lines is controlled by accurately measuring distances with a tape measure. It is imperative to check the corners of a rectangular or square foundation; they must be strictly straight at 90 degrees. Be sure to check the mark of the bottom of the trench with a theodolite, at least at the corners of the house and at the points where the tapes intersect. It must correspond to the design (that is, if you decide to deepen the foundations by 1.4 m, then the bottom of the trench should be 1.4 m below the zero level of the house).

Check the correctness of the axes, their intersections, the angles must be strictly the same as on the house plan.

As mentioned above, pillars should be under each crosshair of the walls.

The pillow is poured generously with water and compacted using a hand tamper. To prevent water from escaping from the poured concrete, polyethylene or roofing felt is placed on the cushion.

4. Installation of formwork

For the manufacture of formwork, boards of any type of wood, 25...40 mm thick and 120...150 mm wide, are used, planed on one side (the planed part is installed facing the concrete). Lumber for formwork should have a moisture content of up to 25%. Wide boards for formwork, as a rule, are not suitable, since cracks appear during their installation. You can also use particle boards, metal structures, and waterproof plywood.

Wooden formwork is preferable to metal formwork, as it is lighter and has less adhesion to concrete. The disadvantages of wooden formwork include the possibility of its deformation and hygroscopicity. The formwork is installed close to the walls of the pit, strictly perpendicular to the base of the foundation, checking this with a plumb line.

In some cases, if the walls of the pit are dry and do not collapse, concrete can be poured without formwork. At the same time, polyethylene is laid around the perimeter so that water does not escape from the concrete.

You can also use asbestos, ceramic, and iron pipes in the form of formwork. Depending on the design of the building, pipes with an internal diameter of 100 mm or more can be used. Concrete is poured directly into the pipes, and they remain in the ground along with the foundation.

When installing wooden formwork, you must remember that the boards must be damp, for which they are well moistened. Otherwise (dry boards) will absorb water, which negatively affects the strength properties of concrete.

If it is possible to use ready-made panel formwork, then this is a plus. Such formworks have a large number of options for their installation, which is very convenient when constructing foundations with a large number of angles. Inventory formwork panels can be rigid or flexible, their length can be from 0.5 to 3 m.

5. Installation of fittings

The pillars are reinforced with longitudinal reinforcement with a diameter of 10-12 mm with a mandatory device, through 20-25 cm of clamps with a diameter of 6 mm. They are installed vertically and secured with clamps or annealed wire to prevent them from diverging to the side. It is advisable to ensure that the reinforcement extends above the top of the foundation (as shown in the figure) by 10-20 cm, so that the monolithic grillage reinforcement can then be welded to them.

Photo of columnar foundation reinforcement.

6. Concrete supply

Here everything is the same as in strip foundations, concrete is laid in layers of 20-30 cm with vibration using manual vibrators.

Photo of concrete being fed into the pillar formwork.

7. Grillage arrangement

The grillage can be made in the form of a monolithic or prefabricated reinforced concrete rand beam.

After completing the installation of columnar foundations, check the marks of the top of the columns and, if necessary, level them with a cement mortar of a 1:2 composition. After this, they begin to construct a prefabricated, precast-monolithic or monolithic reinforced concrete belt (grillage).

The installation of a monolithic belt will ensure proper longitudinal rigidity and stability of the foundation. Before installing the belt, the prefabricated jumpers must be securely connected to each other. To do this, the mounting loops are tied crosswise with twisted wire or connected by welding cuttings of reinforcement with a diameter of 8-10 mm. Then formwork is placed on top of the lintels, a reinforcement cage is installed, and M200 concrete mixture is laid.

Photo of the grillage arrangement for a columnar foundation.

The concrete surface is leveled and covered with any waterproofing material to protect it from atmospheric influences. After gaining strength and waterproofing, you can begin installing the floor slabs.

8. Pickup device

When installing columnar foundations to insulate the underground space and protect it from debris, snow, moisture, dust, cold air, etc. a fence is installed, a fencing wall between the pillars. The fence can be made of various materials, most often stone or brick.

To install a fence between the supports of a columnar foundation, it is necessary to make a concrete screed that will serve as its foundation. The concrete screed does not have a depth; it is placed on a sand cushion, which has a depth of 15 to 20 cm. To install a concrete screed, you will need formwork and a frame made of reinforcement, to prevent possible rupture of the screed due to soil movements.

Place the screed on the concrete screed. As in the plinth, technological windows are made in the inlet for supplying various communications. The pick-up is not connected to the supports, since uneven settlement can lead to the formation of cracks.

The height of the fence must be at least 40 cm. The degree of exposure to moisture on the walls of the house depends on the height of the fence; the higher the fence, the less exposure to moisture on the walls of the house. Also, a house with a low base looks squat; visually it may seem that such a house has no foundation and is built directly on the ground, but houses with a high base look much more attractive and reliable. In this case, the height of the supports must correspond to the height of the base. More details about the design of the plinth can be found in the article

9. Foundation waterproofing

Foundation waterproofing can be done in one of the following ways:

Apply a layer of bitumen to the top of the supports and the fence. Lay a strip of roofing felt on this layer and again apply a layer of bitumen, after which you lay another strip of roofing felt;
On the top of the supports and backfill, apply a layer of cement mortar, in which the ratio of cement to sand is 1:2. After you have leveled the mortar, sprinkle dry cement on top - the layer thickness is from 2 mm to 3 mm. After allowing the cement to “set”, lay a strip of rolled material (roofing felt or roofing felt).

How to perform such waterproofing, and with what materials, you can read in the article .

Important points when building a columnar foundation

When constructing foundations on heaving soils, it is necessary to have a clear understanding that the construction of a house and its commissioning must be carried out in one construction season. Foundations built on heaving soils and left unloaded in the winter (without walls, ceilings and roofs) may become deformed. This is true for all types of foundations, but is especially important for columnar foundations, since each column behaves like a separate foundation (due to the absence of a single rigid frame, unlike a strip or slab foundation). Each pillar gives its own settlement, which in the future (after frost - in the spring) can complicate the construction of the grillage and walls.
Unforeseen deformations can also occur when the built house is not used or heated in winter, and the depth of the foundation was designed for the thermal conditions of the heated house. A favorable time period for laying a foundation is considered to be the period of time when the soil “moved away” from the frost and groundwater descended to the lower layers. This could be the summer months and early autumn.
If you have made the supports of a columnar foundation from monolithic concrete, then you should know that the “readiness” of the concrete is achieved after 30 days. During the entire “maturation” period, no loads should be placed on the concrete supports, and care should also be taken to ensure that the top layer of concrete does not dry out. To do this, you can cover it with film or roofing felt. To ensure that the concrete sets evenly, the supports should be moistened with water from time to time (two or three times a week, depending on weather conditions).
To prepare concrete, it is best for you to use M400 cement. Fine gravel and coarse sand can be used for concrete filler.
An example of calculating components for preparing a concrete mixture:
- cement 20 kg;
- sand 50-55 kg;
- gravel* (crushed stone) 80-85 kg.
Water is added so that the concrete mixture can be easily laid - but not poured!
If the composition of the concrete mixture is too liquid or, on the contrary, too thick, then the strength of the concrete structure is reduced by 25% of the strength of the same structure, during the manufacture of which all the requirements for the proportionality of the components were met.

What mistakes can occur when laying a foundation and how to avoid them

Many developers who decide to build a house on their own often make a number of mistakes when laying the foundation, which lead to varying degrees of damage to the foundation and walls of the house. These errors can be systematized as follows:

An insidious defect of the foundation is the unevenness of its subsidence. This can occur for a number of reasons, which include:
- the foundation depth was not calculated correctly;
- the supports have different depths.
- The load on the foundation supports is uneven.
To eliminate this phenomenon, it is necessary to perform an accurate calculation of the systematic distribution of the load on the foundation. Do not forget to take into account the load on the foundation when adding a second level to the house (for example, building an attic);
The material used was of low quality - the wrong brand of cement, sand that contained an admixture of clay, etc. Or a material, for example cement, has a long shelf life (it should be recalled that when stored for six months, its grade decreases by 25%, and when stored for a year or more by 35-50%);
The load-bearing properties of the soil were not assessed correctly.
A correctly completed project by specialists and constant monitoring of construction by you or an independent expert will help you avoid these mistakes.

Estimated cost of a columnar foundation

Note from the editor: Prices in this article are as of May 2009. Be careful.

The cost of a columnar foundation is determined by the technology of laying the foundation and its depth and consists of the following components:

Prices for laying the foundation:

installation of a sand base 100 mm thick - 80-100 UAH/m2 (or 10-13 US dollars);
construction of a crushed stone base (depending on the fraction) - 80-100 UAH/m2 (or 10-13 US dollars);
concrete preparation device (with a thickness of 10 cm); - 100-120 UAH/m3 (or 13-16 US dollars);
laying reinforced concrete pads or blocks - 160-180 UAH/piece (or 21-24 US dollars);
installation of monolithic reinforced concrete foundation walls - 1300-1500 UAH/m3 (or 179-198 US dollars).

Prices for masonry work:

rubble foundation masonry - 300 UAH/m3 (or 40 US dollars);
laying brick pillars - 250 UAH/m3 (or 33 US dollars);
walls - 600 UAH/m3 (or 80 USD).

Prices for floor installation:

installation of a monolithic reinforced concrete floor (formwork, reinforcement, concreting) - 1300-1500 UAH/m3 (or 170-198 US dollars).

Relationship between contractor and customer.

It would not be amiss to remind you that if the construction of a house is carried out by a construction organization (contractor), then the relationship between you should be built only on a contractual basis.

A construction contract is the main document of the relationship, which stipulates the terms of cooperation, the cost of work, the start and end dates of construction, etc.

The estimate is an integral part of the Construction Contract. It describes all types and costs of work and materials.

The work schedule must include deadlines for completing the work and payment terms for the stages of work.

The contract must also provide for design documents: architectural design of the facility, structural sections of the project and other documents necessary for construction.

For an overview of the types of foundations for a house, read the article.

Owners of land plots, private households, and dacha cooperatives think about constructing a columnar foundation with their own hands when they need to build a small and preferably light structure themselves - a bathhouse, a room for keeping poultry and animals, a veranda, an extension for equipment, a barn. Unlike a strip foundation, making a columnar foundation with your own hands is much easier, and one and a half to two times cheaper. This is especially true for heavy swampy, peaty and waterlogged soils, where sometimes only heavy equipment can cope with this difficult task. But a columnar foundation can be installed by one person with an assistant, quickly and efficiently, without special mechanisms, if he knows how to do it. Therefore the request is “ how to make a columnar one with your own hands step by step instructions» users choose quite often. Let us dwell on this issue.

Types and purpose of columnar foundation

Most often, a columnar foundation is installed for buildings made of wood. Experts do not recommend erecting heavy brick or stone structures on it; the foundation supports under the weight can become deformed and crack over time, which will lead to the destruction of the entire structure. Of course, there are special technologies used in permafrost areas, where the construction of a columnar foundation is the only way to build any structure, but this will require special equipment and knowledge.

Types of columnar foundations.

There are several main types of support-column foundations, united by the same type of construction, but different in the materials used in the construction process.

Monolithic reinforced concrete structure is the strongest existing columnar foundation. It can be used for one or two-story residential wooden buildings.
Brick columnar foundation is the most common, an example of this is buildings 100 and even 200 years ago. The main condition for its construction is high-quality baked brick. On this basis, it is also possible to build 1-2 storey wooden houses on dense soils, and the cross-section of the columns should not be less than 400x400mm.
A block foundation has the same properties as a brick foundation. The only difference between them is the use of materials of different strengths. The most reliable are concrete blocks. The limitation for rubble stone blocks is the high mobility of soils in your area. If rubble material is available, it is better to pour a columnar foundation, a combined rubble-concrete foundation. Concrete, falling between the rubble stones, will secure them and make the structure monolithic and durable.
Wooden-post - used everywhere for light buildings. The main task of builders is to give the entire structure durability, for which long-term and reliable impregnation of wood immersed in the ground is carried out. Wooden supports are treated with antiseptic impregnations and bitumen mastics, after which a layer of roofing material is fixed to their surface. Most often, wooden posts with a diameter of 150-200 mm are used to build verandas and terraces.
Asbestos columns are used for the construction of both light ones - diameter up to 150 mm, and heavier buildings - diameter 250-400 mm. It is possible to use such hollow structures for formwork, followed by pouring a concrete composition inside the pipe, strengthening it with reinforcing bars.
Metal piles are an excellent way to erect a structure on rough and uneven terrain. Finished structures are screwed into the thickness of the earth until they reach dense and stable layers of soil. On an uneven area, it is possible to correct the terrain due to different lengths of the selected piles.

Construction of a columnar foundation with varying degrees of depth

To properly build a columnar foundation with your own hands, you need to calculate its depth in the ground. It depends on many factors, so the recommendations of specialists in your area should not be neglected. Ideally, you need to create a project that takes into account:

Soil freezing depth;
geological features of the site's relief;
underground groundwater level;
soil composition;
climatic features of the area;
weight of the building being erected.

There is a shallowly recessed option, when a depth of 650-700mm is sufficient for installing columns. Such a foundation is recommended for deep groundwater in sandy, rocky and shallow soils that are subject to minimal displacement.

The buried foundation is located at a depth of 1500-2000mm, and often lower. It is recommended to adhere to this depth in areas with deep soil freezing from 450-500mm or with high soil mobility in the construction region. The approximate distance between adjacent columns is 1000-2000mm.

Basic designs of columnar foundations

The construction of a columnar foundation usually does not cause any particular difficulties due to its fairly simple design. The photo shows several options for basic designs for installing a columnar foundation.

The bottom layer in each of the structures is a sand cushion 100-200 mm thick, designed to remove moisture from the foundation area, which is also drainage.
The next layer to be poured is concrete, 400-500 mm thick, forming a concrete pad.
Next, you should place the columnar support itself, reliably waterproofed and reinforced with reinforcing bars, to give strength and durability to the entire structure.
As a rule, the columns are raised above the ground to a certain level to install a grillage or other connecting all the supports of the belt. It will not only tie the structure together, but will also evenly distribute the load between all erected supports.

The grillage for light buildings is usually made of wooden beams with a section of 150x200 or 200x200mm. In the absence of timber, it is possible to arrange a reinforced concrete, metal, brick, rubble-concrete grillage. It can lie directly on the ground, in the form of a strip foundation, or hover above it at various heights of 300-900mm, and sometimes higher. The disadvantage of a high grillage will be the impossibility of building a basement under the building, but residents of flooded areas will appreciate the advantage.

Do-it-yourself columnar foundation step-by-step instructions

1. Preparatory stage

Before building a columnar foundation, you need to select and clear a place, removing all household garbage, weeds, uprooting stumps and undergrowth. After which we proceed to remove the top layer of soil of at least 20 cm and an area exceeding the dimensions of the proposed structure by 2-3 meters.

The next work at the preparatory stage is to compare the topography of the site with filling in the resulting holes and cutting off the hillocks. To do this, use excess soil or a special sand and gravel composition.

Please note that it is not possible to pour a columnar foundation for the future. It is necessary to continue construction immediately after hardening, giving a load to the foundation. Otherwise, the flooded posts may come out of the ground after wintering in the ground.

2. Marking for supports

The most important stage of work is transferring all calculated values from paper to the ground. First, the corner posts are marked out, the main axes of the future house are fixed, they will serve as a guide for drawing all the main lines for laying the foundation and maintaining the exact dimensions. After this, the location and size of all other foundation supports are determined.

Here you can watch a video with the correctly positioned foundation of a house.

3. Construction of a columnar foundation

This stage begins with the preparation of pits for the installation of supports. Holes can be dug manually, drilled with a hand drill, an excavator operator can be hired for these purposes, and in any other available way. The depth of the pit must exceed the size of the installed support by the depth of the drainage sand cushion (15-20cm).

If the technological process requires formwork, then the width of the pits must be increased for its construction.

After preparing the hole, sand is poured into it and water is poured in to compact it. For a reinforced concrete monolithic structure, the sand is fixed with cement laitance, which helps maintain its optimal moisture content.

For a precast foundation, everything is ready to go. For a monolithic one, it is necessary to make a reinforced frame. For pipes - carry out anti-corrosion treatment and impregnation before installing pipes in prepared pits. Asbestos pipes are immediately ready for use.

Photo of how to properly make a columnar foundation with your own hands.

After the preparatory work, concrete is poured directly, with periodic vibration, to get rid of voids and obtain a strong monolith. This will ensure high strength of the base and increase its service life.

To more evenly distribute the load between all the supports of the house, a grillage or tying layer is created. It can be metal - a rand beam, reinforced concrete, or in the form of a strapping beam. This depends on the type and material of the future building erected on this foundation. Before starting its construction, all parts of the supports protruding above the surface are adjusted in height. The video can be viewed here.

4. Waterproofing works

Groundwater and flood waters cause great harm to the foundations being built and the houses on their foundation. Therefore, it is not enough to make a columnar foundation correctly - you need to reliably waterproof it, making sure to include a grillage. To protect the supports, special bitumen compounds are often used, and to insulate the walls of the building, a layer of roofing material fixed to bitumen mastic and adhesive membranes are laid between the grillage and them. Such work is carried out carefully; the humidity regime in the constructed room depends on it. After which, all the resulting voids around the supports are filled with soil, or better yet, with a sand and gravel mixture. Such work is carried out in several stages, with diligent compaction of the laid layer.

5. Pickup

Buildings built on columnar foundations often do not have a basement. Therefore, the distance from the surface of the earth to the bottom of the building requires additional cladding. This is a kind of basement of the building and a lot depends on its arrangement:

Floor temperature;
No drafts from under the floors;
Protection against moisture and dust getting into the underground.

Before complete cladding, provision should be made for ventilation ducts and the laying of utilities - water supply network, sewerage system.

The backyard, after its arrangement, is decorated with brick, stone, facing tiles, decorative plaster - there are no restrictions in this process.

Before starting the construction of the fence, it is required to make a screed with a thickness of 180-220mm, it will act as a support for the walls of the building. The height of the fence-base depends on the height of the grillage and the length of the support pillars protruding above the ground. It is better to leave at least 300-400 mm for these, which is, firstly, aesthetically pleasing, but also practical. In areas with floods and high groundwater levels, the height of the intake can reach impressive sizes and this is economically justified. In addition, a house hovering above the ground at a great height looks quite impressive, despite its design, color and materials used in its construction.

Conclusion

We looked at the main stages of the work and learned in more detail how to properly make a columnar foundation with your own hands. But it’s still better to entrust the design of such a foundation and the entire structure to specialists, especially if you plan to build not just a shed or a toilet on a summer cottage, but a 1-2 storey house for the whole family to live in. Such costs will pay off over time, when the house will stand for decades and will be left as an inheritance to children and grandchildren. For this work, specialists use special software, and today their cost has become more affordable and affordable.

Only a professional builder can design and implement a columnar foundation with his own hands according to the recommendations of SP 50.100, 22.13330, 32.13330, 45.13330, 27.13330. These grounds are too unreliable; the results of geological surveys should be studied in as much detail as possible.

The technology for installing a grillage along pillars depends on the construction technology of the building for which the foundation is being constructed. Columnar bases are made from structural materials:

reinforced concrete - pouring into formwork on site, installing the finished product in a 1F or 2F glass;
wood - logs with a widening base;
brick - clinker, solid ceramics;
blocks - wall, only with dense fillers, hollow;
rubble concrete - stone is introduced into the formwork after partial filling with ready-mixed concrete.

In addition to the strip grillage, a slab structure can be used. This is the only option for a columnar foundation suitable for a brick cottage on sandy soils with a groundwater level (GWL) below 1 m. In all other cases, columnar foundations are created for log houses, half-timbered buildings, buildings made of SIP panels, panel and frame buildings.

Types of columnar foundation by depth

Depending on the geological characteristics of the building site and wall materials, columnar foundations are:

buried - below the freezing mark, groundwater level, but may not reach the bearing layer;
shallow - 40 - 70 cm below ground level;
non-buried - instead of the removed fertile layer, non-metallic material is filled in, the underground part is absent.

The height of the pillars above the zero mark depends on the grillage design and the technological solutions used in the project. The head is embedded into a monolithic grillage at 20 cm, the beams of the prefabricated grillage are installed on top of the piles. Therefore, the height above the surface is always individual. The construction of buried pillars is justified if there is a bearing layer at this level. This type of shallow foundation is stabilized by soil against lateral shift. Non-buried has a minimal construction budget.

Columnar foundation design

The fundamental difference between columnar foundations and piles is the occurrence of the base, as a rule, above the freezing mark, the level of groundwater level, and layers with bearing capacity. Therefore, in any case, the support-column foundation is protected from heaving forces and movements in several ways:

a sand cushion under the base slab; if the base of the foundation is located below the freezing depth, a sand cushion is not required;
drainage of soil by drainage system;
insulation of the blind area and basement.

For the last two activities, open excavation of the soil in the building area is required.

Even with a small depth of the pillar itself, you will have to take into account the thickness of the widening (20 - 40 cm slab) and the underlying layer (cushion of 20 cm sand + 20 cm crushed stone). In addition, you will need a ring ditch for laying drains and access for workers to the lower level. Therefore, the size of the well and trench increases several times; it is inconvenient to carry out work from the ground at depth.

Manufacturing columnar foundations by analogy with bored piles is a gross violation of technology. It is difficult to widen the sole; there are heaving forces underneath it. The side walls without backfilling with sand are subject to tangential forces of the same processes.

Thus, the correct design of a columnar foundation looks like:

preparation - sand (layer thickness 20-40 cm) with layer-by-layer compaction with a vibrating plate, pouring;
footing - serves exclusively for laying waterproofing, is a 5 cm screed;
stepped plate (sole) – distributes loads due to the increased surface of the sole;
pillar - a vertical post made of monolithic or precast concrete;
grillage - reinforced concrete products, monolithic structure, timber or rolled metal (channel, I-beam).

Unlike piles, pillars do not have spatial rigidity, so the grillage beams must not just rest on their heads, but must be attached to each pillar to be connected into a single structure.

Step by step instructions

Due to the variety of operations for constructing a grillage on pillars, step-by-step instructions are necessary for the individual developer as a guide. If you skip any stage, you will have to redo the work later or return to it, spending more effort and money.

For example, the instructions recommend laying drains at the excavation stage. If you forget about them at the beginning and remember them when landscaping the area, the trenches will have to be dug again, construction will be delayed, and the site will again be clogged with soil. The height of the pillars is selected 20 cm above the bottom of the grillage for walling in concrete.

Below we will tell you how to make a columnar foundation with your own hands correctly.

Geological surveys and calculations

The technology for constructing a columnar foundation depends on the results of geotechnical surveys, wall material, and construction technology. For example, it is prohibited to leave unloaded poles in the winter even if they are tied with a grillage.

Prefabricated loads (the weight of the building, residents, furniture, belongings, wind, snow loads) may not be enough to compensate for the extrusion forces, or the building will gradually sink into unstable soil with excess weight.

Unlike the test screwing of screw piles in the technology of the same name to find the depth of the bearing layer, full-scale surveys are required here, costing at least 30 thousand rubles. The designer needs the following data:

layered arrangement of layers;
composition and characteristics of the three upper layers;
GWL level;
frost mark.

The cross-section of the pillars should be greater than 40 x 40 cm for concrete or brickwork, 20 x 20 cm or 20 cm in diameter for a monolithic reinforced structure.

Marking and excavation work

Unlike bored piles that reach the bearing strata, it is much more difficult to pour pillars into wells. The main problem will be the lack of sand filling in the sinuses:

after a few years, the soil near the body of the pile will self-compact;
will gain moisture and freeze in winter;
heaving forces will pull the pillar out like a carrot from a garden bed;
if there is a lower widening, the column will rise upward due to heaving forces, and soil will crumble under the base;
the slab will not allow you to pull out the entire column, but it will no longer be able to get back into place.

We dig holes to widen the columnar foundation.

Therefore, the only correct way would be to mark the trenches, taking into account the width of the base, the drainage contour, and the construction of formwork. Instead of a square shaft of 40 x 40 cm, you will have to remove much more soil, 1 x 1 m minimum. In this case, the thickness of all layers of the foundation pie and the height of the groundwater level are taken into account. If the last characteristic is slightly below a meter, you need to go deeper by 0.6 m, no more.

Preparation

By default, the construction of a monolithic foundation of a dwelling should provide protection from corrosion and destruction. In the absence of oxygen, the only aggressive environment underground remains moisture, which should be removed from the base with drains and stopped at the surface of concrete structures along the entire height with a waterproofing carpet.

Construction is carried out in stages:

layer-by-layer backfilling - 20 cm of sand with moistening, vibration compaction twice (total height 40 cm);
footing – screed height 5 cm, no reinforcement;
waterproofing – 2-3-layer carpet of rolled material on a fiberglass base;

Reinforcement

The technology for constructing an armored belt for a column with an expanded base is as follows:

knitting reinforcing mesh to the size of the slab, taking into account the side protective layers (40 mm from the formwork to the metal) with a cell of 15 x 15 cm or 20 x 20 cm with a thickness of 12 - 16 mm;
joining to the mesh rods bent at right angles of 12 - 16 mm, protruding 20 - 30 cm above the base of the grillage (usually 4 pieces in the corners, one in the middle of each side);
vertical rods are reinforced with horizontal square clamps made of 6–8 mm reinforcement;
the structure is installed on a waterproofing carpet, which extends 10-15 cm beyond the dimensions of the sole, for subsequent bending onto the side edges of the sole.

It is prohibited to lift the reinforcement structure with metal scraps, bricks, or crushed stone to provide a protective layer.

Widening the pillar

The construction of the sole involves pouring the slab into the formwork. The widening area is twice the cross-section of the column, the height of all elements is a multiple of 30 cm. The formwork is simple - four boards fastened with screws, corners or bars at the bottom of the pit or trench.

Reinforcement of the widening and pillar.

The sides of the formwork should be slightly higher than the design level in order to properly level the concrete surface. The permissible error in the horizontal plane is 1 cm. Filling is carried out after installing the reinforcement structure.

Formwork

We install and strengthen the formwork for the columnar foundation.

Drainage and waterproofing

From the perimeter of the building it can be made at any stage, from foundation pit to backfill. To install drains, a circular trench with a uniform slope towards the underground tank is required. Dornite or geotextile is spread at the bottom, and 10 cm of crushed stone is backfilled. Perforated pipes in the filter are laid in it, and inspection wells are installed. After which, the communication is filled with another 10 cm of crushed stone and covered with the remains of geotextiles.

Waterproofing device - several technologies using different materials:

impregnations - contain penetrating additives that change the molecular structure of concrete, making it waterproof throughout its entire depth;
rolled materials - Bikrost, TechnoNIKOL and other analogues on a fiberglass base, laid in two layers;
coatings – epoxy and bitumen based mastics;
paints – enamels based on bitumen resins.

Most often, combined methods are used to achieve a 50-70 year resource. Rolled coating materials will have to be renewed every 15 years.

Ready-made columnar foundation with reinforced concrete grillage.

Backfill

After installing drainage and a continuous waterproofing layer over the concrete surface, it is necessary to protect the side surfaces from heaving forces. The sinuses are filled with sand; compaction is necessary, since loose soils are extremely unstable. The chernozem of the fertile layer is saturated with organic matter and settles after it rots. Other soils contain clay, which swells in cold weather. Therefore, exclusively non-metallic materials are used, in which there is less heaving.

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The choice of foundation for a house or other building is influenced by many factors. For each specific case, a different foundation design can be used. In first place in terms of frequency of use is the strip structure; for unstable soils, a pile foundation is common. It is quite simple to build a columnar foundation with your own hands, which in some respects is not inferior to the listed foundation options. This design has its own variations and nuances in the bookmark. Each of these points will be discussed in the article.

Benefits of the solution

During the use of this type of foundation design, users and builders managed to compile a certain list of positive qualities that were identified. Among them are:

possibility of independent design;
relative simplicity of calculations;
possibility of use on various types of soils;
Possibility of use in areas with level differences;
the ability to avoid site planning;
high construction speed;
long service life;
relatively low project cost.

Perhaps these nuances do not apply to all types of columnar foundation designs, but for a classic structure with a concrete grillage this is exactly the case. There are also disadvantages, of which there are significantly fewer. One of them is the impossibility of constructing heavy buildings whose walls are made of brick. The latter is capable of exerting significant pressure on the base, which often leads to destruction. This occurs due to shrinkage, although on an industrial scale this foundation design is used for brick buildings on soils with permafrost. Another unpleasant point is the inability to build a basement or garage directly under the house, since a foundation of this type does not provide for laying a monolithic structure to a great depth.

Pay attention! Columnar foundations are most often used for the construction of structures that use gas-filled blocks or are made using frame technology. Construction of buildings made of rounded logs is also allowed.

Types of designs

The design of a columnar foundation will largely depend on the specific building it will be used for. If we are talking about an ordinary gazebo, then its dimensions will be significantly smaller than those needed for a bathhouse or cottage. Based on the material used, the types of columnar foundations can be divided into:

monolithic with a concrete grillage;
monolithic with a wooden grillage;
brick;
bud-filled;
rubble concrete;
wooden;
monolithic from asbestos pipes;
columnar-pile.

The first design option is the most durable. This is due to the fact that the pillars and grillage are a single structure that is capable of evenly distributing the load exerted on all pillars. This design is more expensive than others, but will last much longer. Such a columnar foundation allows the construction of houses of several floors using frame technology or from logs. The next version of a columnar foundation with a grillage is made using a similar technology. Its pillars are also filled with monolithic concrete with reinforcement; only wooden beams are laid on them, which form the basis for the walls of the structure.

Most often, when they talk about a columnar foundation, they mean the third design option, which is laid using bricks. Unlike previous options, a columnar brick foundation is quite simple to construct and requires relatively lower costs. With good soil quality, as well as the right approach to construction, a service life of several decades can be achieved. Many ancient buildings that have survived to this day were built precisely on this type of foundation. In some areas, it is possible to build a house with several floors on a foundation of this type.

Pay attention! Other types of blocks can be used as the basis for a brick foundation. In this case, the strength and stability of the base will depend entirely on the quality and strength of the material used.

A rubble-filled columnar foundation is laid using brick or stone from old structures. This solution is suitable for stable soils and for areas where there are no level differences, since the stability of such a foundation is significantly lower than that of previous options. The base of the structure made of rubble concrete is also built using the materials mentioned above, but the connecting link in this case is cement mortar. The result is a monolithic, but not reinforced structure.

The wooden base of the structure is now practically not used, but it still remains relevant for areas where it is necessary to raise the structure to a considerable height in order to avoid flooding. This applies to warm parts of the world. A similar method was used in other areas, but proper implementation requires special treatment of the wood to prevent rotting and drying out. A wooden columnar foundation is an excellent solution for additional buildings near the house. This applies, for example, to terraces. In addition to antiseptic impregnations, wood is also coated with waterproofing material. As the latter, bitumen mastics are often used.

Another interesting design option is a foundation made of asbestos pipes. Most often, it is manufactured using a solution similar to a monolithic columnar solution. In this case, the pipes act as formwork, into which reinforcement rods are inserted and concrete solution is poured. Usually a pipe with a diameter of 20 cm or more is used. A column-pile foundation is made using screw or other types of piles. In the first case, no special equipment will be needed to build the foundation, except for a concrete mixer. Screw piles can be installed in place by a small crew of three people.

The advantage of this solution is the greater stability of the structure base. This is due to the fact that the pile is immersed to a considerable depth, which passes the freezing level and reaches dense layers of soil, where fixation is carried out. The design with screw piles can be used for a log house or a frame house. If we are talking about bored piles, which are intertwined with a metal frame with a concrete grillage, then such a foundation is used when constructing houses from blocks.

Varieties by depth

The difference between foundations is made not only by the materials that are used to lay them, but also by the depth to which the foundation is mounted. To put it simply, then, as with strip foundations, there are two types:

shallow;
buried.

In the first case, the immersion is usually 50 or 80 cm, which somewhat reduces the cost of equipment for the base itself. This support structure is used for buildings that are light in weight. A recessed structure involves the use of supports that go 150 or 200 cm into the ground. This depends on the level of freezing. This design is more preferable for areas where there is heaving soil or high instability of the upper layers. In addition to the depth of the base, the height at which the grillage is located also varies. In this regard, the following are distinguished:

aboveground;
ground;
buried.

Above-ground foundation design options are excellent for cases where the upper layers of the soil have a high degree of heaving. If the grillage is laid directly on the ground, there is a possibility of distortion or damage. In the case of constructing an above-ground version of the structure, the pillars are made of greater height in order to raise the grillage to a certain height. The disadvantage of this solution is the need for additional floor insulation. This is due to the free ventilation of the space under the house. Usually the sides are closed and only small openings are left for ventilation.

The ground version of the structure is built on a prepared bed of sand and gravel. It is placed so that it is flush with the surface. On the one hand, this eliminates strong blowing, as is the case with the above-ground version of the structure, but on the other hand, for such a structure there is a need for a correct approach to waterproofing. The shallow version of a columnar foundation is very similar to a similar strip foundation, but additionally, supporting elements in the form of pillars or piles are prepared in the trench, which are sunk to a considerable depth. The second and third options are most often implemented using a concrete grillage.

Basic Concepts

Almost all types of columnar foundations have one principle according to which they are constructed. Certain nuances are important to consider in order to achieve success. Among them:

pillar pillow;
heel support;
column design;
arrangement of columns;
grillage device.

If we are not talking about pile supports, then preliminary backfilling must be done under the posts. For these purposes, medium-grained sand is usually used. The thickness of the pillow itself depends on the amount of moisture in the soil, as well as the expected weight. It can reach 30 cm, and the minimum permissible value is within 10 cm. If additional drainage is required, then an additional layer of crushed stone is laid under the columns, which allows water to pass through faster than sand. The functional purpose of such a pillow is to uniformly distribute pressure, as well as reduce the level of humidity under the posts.

For monolithic columns, which are made by pouring, soles are made, which are a small concrete slab with a thickness of up to 50 cm. It is wider and longer than the supporting column in order to increase the interaction area. The next nuance of such a foundation is the need for reinforcement. If we talk about a monolithic foundation, then there are no questions regarding reinforcement, but this also applies to other options. Only in this case is external reinforcement carried out, which eliminates the deformation of the columns. To prevent moisture from rising to the grillage and the building, it is necessary to approach the issue of waterproofing correctly.

It is important to correctly determine the number of columns in the foundation and distribute them throughout the area. This will determine how the load will be distributed. The projection of the posts above ground level will depend on the placement of the grillage, as well as the topography of the area. In some cases, owners of houses on columnar foundations prefer to make a fence. This is an additional concrete structure that is placed between the columns to cover the underground space. Reinforcement is also required for it. The fence for the columnar foundation further strengthens the entire structure.

Pay attention! In areas where flooding is possible, the height of the pillars can reach up to 2.5 meters above ground level. The calculation is based on the maximum level to which the water rose in the area.

Self-calculation

The key to successful completion of the construction of the structure is the calculation of the columnar foundation and preparation of the project. They begin even before the process of preparing and planning the site for the foundation. It is better if a professional in his field provides assistance in drawing up the project. Thanks to this, it will be possible to take into account all the nuances that relate to the soil and the expected load. The wishes of the customer himself are also taken into account. The main initial parameter for drawing up a design project is the area allocated for the building. The next important indicator is the mass of the structure. To correctly draw up all the documents, you will need a geodetic survey of the area and linking the future structure to a specific site.

During the design, the following points will also be taken into account:

soil specifics;
proximity of aquifers;
soil freezing level;
number of floors;
materials for construction;
possible additional loads.

The first and second factors will determine the required depth of columns or piles for the foundation structure, as well as their level above the ground. The third factor is necessary to determine below what depth the supporting elements of the foundation should be located. The number of floors affects the number of supporting elements, as well as the choice of material for construction. Additional loads that may be caused by wind, changes in soil or precipitation are taken into account. All these factors give a clear understanding of the number and parameters for the pillars of the future foundation.

With sufficient experience, you can try to perform the design work for the structure yourself. To do this, you will need to collect all the data relating to a specific area. They can be found on the official websites of various services or obtained directly from the services. When taking readings, knowledge of many formulas will be required. But even the use of online assistants may not help, since important factors that can only be assessed while staying at a specific site will be missed. If you turn to specialists who have already performed dozens of calculations for a specific region, you can be sure that they have a good knowledge of all the nuances of the soil in the area. In addition, professional services involve the issuance of specific documents that will be required when obtaining the necessary permits for construction.

Construction process

Each foundation design option has its own construction nuances, so it’s worth considering step-by-step instructions for several options. The first of these will be a monolithic columnar foundation.

Monolithic option

After drawing up the design design, it’s time for practical work. The first step is to prepare and mark out the area for a monolithic columnar foundation.

As you can see in the photo above, it is necessary to pre-mark the area where the structure will be located. To do this, the corners of the building are marked with pegs. A clearly visible rope or twine is stretched between the latter. Particular precision of angles is not required, since the marking of the structure is carried out for preliminary preparation of the area for construction.

The next step is to remove the top layer of soil along with the vegetation that is located on it. To make work easier, you can compact the area to make it easier to move around.

When the preliminary stage is completed, you can move on to more precise marking of the foundation structure. To do this, the corner pegs are placed exactly in their places, and the distance between them is checked. It is also necessary to determine whether the diagonals of the resulting figure of the future foundation structure are equal. If they do not match, then it is worth finding out which of the corners has the wrong angle and moving one or more columns.

In accordance with the developed project, markings are applied to the columns that will be installed later. For these purposes, additional stakes and ropes are used. The latter are stretched in places where the rows of columns will pass. The photo shows that the string, which is stretched in the middle, marks the edge of the pillars of the foundation structure. Simultaneously with this procedure, notes are made on where exactly the columns for the foundation will be located.

If you pay attention to the photo above, you can see that the master specifically marks the boundaries of the pit for the post. To do this, four pieces of reinforcement are driven in along its edges, which makes orientation easier during digging. You can start with it immediately after marking a specific element of the foundation structure. This can be done mechanically or manually. Everything will depend on the quality of the soil that exists in a particular area. A square heel with a side size of 40 cm is considered standard, but in certain cases it can be increased to 80 cm. It is this size plus the gap for the formwork that the foundation pit for the column should be.

The distance between individual pillars of the structure can vary from one to three meters. When the pit for the foundation column is ready, it is necessary to waterproof the lower part, where the heel of the supporting element will be poured. In the photo above you can see that for this purpose a polyethylene oilcloth is laid on the bottom. The density of the oilcloth should be 200 microns. It is located with a twist on the walls. Additional waterproofing and at the same time formwork for the structure is bikrost, roofing felt or similar material that does not have powder. Waterproofing can be fixed to the wall using nails or other fasteners. Subsequently, it will be pressed down by concrete. The height of such formwork should be equal to the height of the heel, which will be poured under the column.

The next step in constructing a columnar foundation structure is the preparation of reinforcing elements that will be poured with concrete. For these purposes, rods with ribs that have a diameter of 10 mm or more are used. It is necessary to calculate the elements in such a way that the heel is larger in size, and the vertical reinforcement corresponds to the post. The height of the reinforcement must be sufficient to combine the pillars with the monolithic foundation grillage, which will be poured later.

To make it easier to bend the reinforcement, you can make a similar device to the one shown in the photo above. For this, two metal corners are used, which are screwed to the wall. Moreover, their length is equal to the length of the element that will bend. The distance between the two strips is equal to the diameter of the reinforcement that is used for the foundation. To make it easier to bend the rods, you can use a metal pipe as a lever.

To make it easier to assemble the sheathing, stands are made, as shown in the photo above. A support is screwed to the vertical plane, in which notches are made at a distance from the reinforcement bars that will be embedded in the column. Additionally, a stand is made that can be rearranged depending on the length of the reinforcement. She can be seen on the right.

After this, the horizontal structural elements are distributed at an equal distance. To do this, use a tape measure or other device. The next step is to lay two more vertical posts, as seen in the photo above. To fix the structural modules together, it is necessary to use a binding wire that securely clamps them in place. For knitting, you can make a small hook yourself, which will simplify the task.

Reinforcement under the heel is performed separately and is represented by a small square in which rods are laid perpendicularly, as shown in the photo above. They are tied at all intersection points to ensure reliable fixation.

Next, preparation of the support stands of the structure is carried out, which will raise the reinforcement under the heel and under the column a short distance from the ground. This is necessary so that the element is filled with concrete mortar and from below.

The reinforcement for the heel structure is installed on plastic legs, and the reinforcement for the posts is fixed on top. All elements are tied together with knitting wire. So that it turns out as shown in the photo below.

Once the reinforcing elements for the columnar foundation structure are ready, formwork is manufactured for each column. An OBS board with a thickness of more than 12 mm is perfect for this. If you take a material with a smaller thickness, it will bend under the pressure of the concrete solution. To properly reinforce a columnar foundation, concrete must cover the mesh by at least 5 cm on each side. This means that the length and width must be 10 cm greater than the reinforcing elements. The height can be 5 cm greater.

To fasten the walls of the formwork under the posts together, hangers for a plasterboard profile are suitable. In this case, the middle part of the structure is cut out and only perforated strips remain, which are bent into the corners, as shown in the photo below. They are screwed to the walls and combine them into the required structure.

When all the elements are ready, they are assembled into a common structure, which will ensure high-quality pouring of the foundation.

In order for the OSB structure under the foundation columns to have a sufficient water-repellent effect and not to swell under the influence of moisture from the solution, it must be covered with cold-prepared bitumen mastic. This is done both externally and internally.

The next step is to install the armored belt under the foundation structure in the prepared pits.

The frame must be placed exactly in the middle of the prepared pit so that the concrete solution can freely and evenly fill the space around the structure. In addition, the structure must be exactly vertical and level. To achieve this, you can resort to the trick shown in the photo below.

A regular bubble level is used to ensure the structure is vertical. After this, the reinforcing base is tied to an additionally laid beam so that there is no displacement during pouring. The beam is fixed with weights in the form of bricks or other devices.

In this way, all elements that are responsible for the stability of the columnar foundation structure are installed.

Next, concrete is mixed for the foundation structure. The columns will be filled in stages. The first step is to fix the heel of the column under the foundation. It is enough to knead for each heel. The mortar for the foundation structure can be laid with a shovel. Its level will be equal to the height of the prepared waterproofing. To evenly distribute the concrete in the heel under the foundation, you will need an electric vibrator. It is lowered into the solution to fill any voids and remove air that could weaken the foundation post structure.

All that remains is to wait for the time during which the heel under the foundation column gains strength. As soon as this happens, you can begin installing the formwork for the column, which was prepared from OSB sheets. The formwork is placed in such a way that the reinforcement is located in the middle.

If you pour concrete into the formwork without fixing it, this will lead to displacement of the formwork and disruption of the foundation structure. Therefore, it is necessary to perform backfilling, which will fix the formwork under the foundation column. When performing backfill for the foundation structure, soil may get into the column form. To prevent this from happening, the upper part of the formwork structure under the foundation is covered with a thick film, as shown in the photo above.

Additionally, it is fixed to the formwork using a construction stapler so that the oilcloth does not move during operation.

For backfilling, you can use the soil that was removed when digging pits for the foundation columns. It is carefully poured between the pit wall and the formwork under the foundation column. After this, compaction can be done using a hand tamper, which can be easily made from a log and a small handle-shaped crossbar.

To protect everyone who will move around the construction site, it is necessary to cover the protruding rods with plastic bottles. The latter are easy to find and will do the job perfectly.

To make the backfill dense, you can additionally compact it with water, which will allow the soil to sink under its own weight.

The protective film is removed from the formwork under the foundation column. There are small pebbles and other debris left at the bottom of the structure that may interfere with good adhesion. To eliminate this, you can remove them using a regular or industrial vacuum cleaner, the tube of which will be tied to a pole, as shown in the photo above.

Before pouring the next portion of concrete under the foundation, it is necessary to wet the heel under the foundation, as well as the formwork. This is done for better interaction between the components of the foundation structure. After this, you can fill the column into the prepared formwork. The solution must be compacted with a vibrator to eliminate the presence of air in the structure. To ensure that the foundation column does not lose too much moisture during the process of gaining strength, it is necessary to put an oilcloth on the foundation reinforcement, which prevents soil from getting inside the column.

After pouring the foundation columns, you can begin digging a trench between the foundation columns. In this case, a trench will be needed to construct a grillage for the foundation. Its depth is calculated in such a way as to accommodate a cushion of gravel and sand. The second in this case will be 30 cm, and the first will be sufficient at 15 cm. In this case, it is also necessary to decide at what level the foundation grillage will be located. If it is a little deep, then you need to go deeper to this level.

The first to be laid is a sand cushion under the foundation structure, which is well compacted. Next, the second cushion is backfilled under the foundation in the form of fine crushed stone. It also needs to be compacted well in order to achieve uniform distribution of the load from the foundation to the ground. For this, a gasoline or electric vibrator is used. It is best to work by placing it perpendicular to the trench under the foundation, so as not to collect rubble along the edges.

When the backfill for the foundation structure is ready, you can proceed to the construction of formwork for the columnar foundation. Wooden beams will be needed. The length of such a beam for foundation formwork should be such that it can be 45 cm immersed in the ground and protrude to the full height of the foundation grillage. To make it easier to hammer the timber into the ground, it must be sharpened from below with an axe, as shown in the photo.

After this, the element is leveled and driven in with a sledgehammer to the required depth. It is necessary to periodically check the level of the structure, as it may go astray. In addition, this will be the key to the correct installation of formwork under the foundation.

A board is nailed to the installed supports under the formwork. It is necessary to arrange the individual elements for the foundation formwork in such a way that there are no gaps between them.

The foundation formwork board will deform from exposure to moisture, so it must be protected. The easiest way to do this is to use plastic film. It is fixed to the boards using a construction stapler.

To strengthen the formwork structure, jibs are installed that rest against another rack. The elements are mounted through one rack. The free racks are connected to each other using a knitting wire, as can be seen in the photo below.

Additionally, transverse elements are nailed on top of the structure, which tighten the walls of the foundation formwork together. It is first necessary to lay reinforcement inside, since this will be problematic later.

Pay attention! To reinforce the foundation, reinforcement with a diameter of 14 mm is used. In this case, the clamps can be made from rods with a diameter of 8 or 10 mm.

The reinforcement that remains protruding from the foundation columns must be bent to intertwine it with the reinforcement for the grillage. It is tied to the rods, which are laid in the formwork using a knitting wire.

When everything is ready, you can pour the foundation with concrete. This is easier to do with a concrete pump, which can be directed along the entire perimeter of the foundation. After pouring, the foundation grillage is processed with a vibrator and leveled with a trowel.

When the foundation has gained a sufficient measure of strength, the formwork can be dismantled and the foundation can be cleared of soil residues. You can clearly see the process of installing the structure of this foundation in the video below.

With brick pillars

This design option is constructed somewhat simpler than the previous one, but it is worth understanding that a columnar foundation made of blocks cannot be used for serious buildings. It is perfect for sheds or gazebos where the weight will be minimal. Marking for this type of foundation structure is carried out in a similar way as for the previous option.

The pits for the foundation columns are constructed with a small margin so that the support pad is slightly larger than the area required to support the blocks. Crushed stone is laid at the bottom of the prepared pit. Its layer can reach 20 cm. It is important to compact the material well. It not only ensures proper distribution of the load, but is also responsible for drainage, which will eliminate the impact of liquid on the laid blocks.

After laying the crushed stone, sand is poured. Its layer will be ten or more centimeters. It is important to compact it well and level it in a horizontal plane.

After this, you can proceed to laying the blocks. They are leveled and secured with cement mortar. The second row is laid out perpendicular to the first to ensure ligation of the seams for greater structural strength. Foundation waterproofing in the form of roofing felt is laid on top of the blocks. It is necessary to prevent moisture from entering the grillage, which can rot from it. A wooden beam with a cross-section of 15 cm is most often used as a grillage for such foundation structures. It is laid along the entire perimeter of the foundation.

At the intersections of the structure, weaving is done using a tenon joint. The photo shows that two beams can also be connected using the half method. In this case, in each of the elements for the foundation grillage, a cut is made to half the thickness and width of the log. After this, the two foundation elements are fixed to each other using a pin or a self-tapping screw with a hex head.

Pile option

The next option for foundation design, which can also be classified as columnar, is a pile foundation with a grillage. For independent construction of the structure, screw piles are suitable, which are easiest to install without additional equipment. Such a foundation is sufficiently reliable and allows it to be anchored in strong layers of soil. This is done quite simply, since piles for such a foundation can be selected in a wide variety of lengths. The only question will be the convenience of screwing them in. In some cases, additional platforms will be required when work begins. But most often such a foundation is installed without them.

The issue of marking for a foundation design based on screw piles at the initial stage is relative. This is due to the fact that during work you should push off from the first pile. Its installation for the foundation is determined by the plan, which indicates exactly how the house should be located on the site. It is necessary to choose any corner of the foundation from which it will be convenient to start work. This pile will be the starting point from which it will be easy to make the rest of the measurements for the foundation.

It will be easier to install the pile if you prepare a small pit for it. Typically, a depth of 30 cm is sufficient for these purposes. The diameter of the pit is made slightly larger than the diameter of the foundation pile. You can dig it out with a garden drill, if its diameter allows this, or with a regular shovel.

It will be easier to install such a foundation if you do not just screw in the pile using a lever that is inserted into the hole, but with a special device. You can rent a pile sleeve, as shown in the photo above. Thanks to the arcs that are located on the sides of the coupling, it is easier to transmit force from the lever, which is in any position. In this case, the immersion of the pile under the foundation proceeds smoothly. Rotating a pile under the foundation through a hole that is located on top is not always convenient, since there may be restrictions on the area of movement around the pile.

As a lever that will be used to immerse the pile into the ground, one pipe will not be enough, since the direction of the force that will be applied with its help can change the position of the foundation pile, which is very inconvenient. To build the structure you will need at least two levers. The length of each is from three meters. In some cases, longer levers will be required to properly install the structure if the pile must lie quite deep.

To make installation of the structure easier, at least three people will be required. Two of them act on levers. The third person’s task at the initial stage is to keep the pile in a vertical position. As long as the main part of the pile is on the surface, there is no point in using a bubble level for the structure. This is due to the fact that the pile still has a significant amplitude of movement.

Pay attention! The wall thickness of the lever must be at least 3 mm in order to provide the required force for screwing in the pile.

Screwing occurs clockwise. This can be determined by the direction of the screw at the end of the pile structure. As you can see in the photo, the main load during screwing of the structure for the one who holds it in a vertical position falls not on the hands, but on the shoulder. Hands act as assistants, since it is almost impossible to grasp a pile of such diameter well. The emphasis is supported by half-bent legs with legs widely spaced.

As soon as most of the pile structure is in the ground, it is necessary to increase the force, since screwing will be more difficult. To do this, the levers are extended to their maximum distance so that only a small part engages the coupling arcs.

As soon as it becomes clear that the pile has taken a good position and is firmly held by the soil, you can proceed to the precise vertical positioning of the structure. To do this, you will need a level that can be fixed to the body of the pile with a magnet. The photo shows that the level is located on the pile for a reason. It is placed perpendicular to the two support arms. This is the only way to correctly track the position of the pile. To make monitoring easier, you can use another level, which is installed directly under the lever.

When the level is in place, you need to position the structure in a slightly different way. If in the previous version the pile was held by the shoulders, now it needs to be leveled with the weight of the body, directing it in the opposite direction from the one in which the pile is tilting. Support is also provided on legs widely spaced and bent at the knees.

The deeper the pile goes, the more effort will have to be made to guide and rotate it. You may have to enlist the help of a few more people, as can be seen in the photo.

When the installation of the first element of the foundation structure is completed, it is necessary to determine the point at which the second corner pile will be located, which is in line with the first. It is best to take measurements at the centers of the circles. This means that the end of the tape measure is installed on the central part of the pipe. The distance to the center of the second pile for the foundation is measured. It will be equal to the total length or width of the house, from which the width of one wall is subtracted. Once the distance is determined, it is necessary to position the foundation piles on the same line. The easiest way for these purposes is to find a common landmark, for example, a fence, and place the foundation structure at the same distance from it.

The second pile is screwed in in the same way as the first. But now it is necessary to monitor not only the vertical level of the foundation pile, but also the distance at which it is located from the first pile. If in the process there is a need to adjust the position of the structure, then you should not act by simply tilting it in the intended direction. The photo shows that the pile must be tilted in the opposite direction to the one in which it is necessary to align the pile. After this, two turns of the pile are made under the foundation, and it is leveled to a vertical position. If this fails to achieve the desired effect, then the operation must be repeated.

When two piles are already in place, you can proceed to the installation of the third. The point of its installation is calculated somewhat more complicated than in the first and second cases. To install the third pile of a columnar foundation structure, you must be guided by the Pythagorean theorem. The width of the building is known, the length is also known, now you need to calculate the diagonal or hypotenuse of the right triangle. To do this, the thickness of the wall is subtracted from the width and length, since the measurement is taken at the centers, and each figure is squared. The sum of the resulting numbers will be the size of the diagonal. The photo shows that one of the ways to mark the third point of the foundation structure is to use two tape measures. At the intersection of the required values, the location of the third pile is located.

Pay attention! If you don’t have two long tape measures, then you can use twine on which the required size is marked.

After determining the location of the third pile under the columnar foundation, preliminary installation of the pile is carried out in the pit prepared for it. Once it is securely in place, it is necessary to re-measure to ensure that the foundation pile is in place. If there are certain errors, then it is necessary to level the foundation pile in the manner described above.

When the installation of the pile in place is completed, it is necessary to further secure it. To do this, the pit that was dug earlier is filled with soil. It is important to compact the latter well so that the upper part of the foundation pile does not become loose.

The fourth pile under the foundation is also mounted using the diagonal and wall dimensions. In this case, all the indicators are known, so you can use tape measures or twine and screw the pile into place under the foundation. Periodically, when screwing the pile into place, it is necessary to check whether the distances at which it should be in relation to other piles are maintained.

The support of the entire structure is ready, now it will be easier to install the remaining piles under the foundation. For these purposes, a string is stretched between all risers. It must be located as close to the ground as possible. It will be easier to operate if two strings are pulled between the foundation piles, which will mark the corridor in which the piles should be located. Each wall is divided into two halves. The resulting size is marked on a stretched string and a pit is dug under it for the pile of the future foundation. This must be done on all four sides of the house.

During screwing, it is necessary to ensure that the marked point is at the center of the pile pipe. All foundation piles are immersed to the required level.

Foundation piles will also be required for interior walls. To mark them, you can use the intersection points between the lines of existing piles. To do this, ropes are stretched between the piles, which are clearly visible. At the intersection points, where necessary, a pit is prepared and the pile is screwed in. At the same time, it should be positioned in such a way as not to strain the rope or deflect it. It is important to monitor the level of the foundation pile throughout the screwing process.

The pile should be located at the intersection of the stretched ropes as shown in the photo above. The ropes are tangential, so the center of the foundation pile does not coincide with the center of the pile that will be screwed in.

Once all the piles are in place, it is necessary to trim them horizontally. This will allow you to correctly position the foundation even on an inclined area. For this purpose, you can use two tools. One of them is a laser level. It's easier to use. It is enough to position the beam at the required height and project it onto the body of the piles. After that, markings are applied to the foundation piles and trimming is done with a grinder.

Another option is to use a water level. Before use, it must be well aligned to avoid any bends. Next, the container containing water for the hydraulic level is installed on one of the piles. One of the craftsmen lowers part of the tube into a container, and the second creates a vacuum so that water under its own pressure begins to fill the tube.

Next, the functionality of the hydraulic level is checked. Its two ends are connected together and a certain time is waited. After this, the liquid in the two pipes should reach the same common level. If this happens, then you can proceed to the process of measuring the height for the foundation piles. If not, then you should carefully examine it and identify kinks or places where airing has occurred.

Pay attention! The longer the hydraulic level, the more time it takes for the liquid inside it to calm down.

On one of the corner piles of the foundation, a point is drawn where all foundation piles should be located. One part of the hydraulic level is applied to it, and the second is brought to the next corner pile. Once the water level has calmed down, you can make a mark on the pile to guide the cutting. This way the mark is transferred to all corner piles of the foundation.

To mark a line over the entire area of the foundation pile, it is necessary to make a pattern from a plastic pipe, which will be cut on one side for ease of installation on the pipe. Using a marker, draw a circle.

To transfer the marking line to the remaining piles, which are located in the middle of the foundation structure, it is necessary to pull a strong fishing line along the marks on the outer piles. It will be the indicator of the required line. After this, marking is carried out with a marker at the selected point. Using the prepared pattern, a line is drawn over the entire area of the piles.

Once the marking of the piles for the foundation is completed, you can proceed to cutting all the elements along the drawn lines.

The next step is to fill the installed screw piles for the foundation. This is not done with concrete, but with an ordinary cement-sand mortar in a ratio of three to one. The solution must be liquid enough to fill the pile cavity. The purpose of this procedure is not to impart additional rigidity to the foundation, but to prevent the exposure of the internal walls of the pile to oxygen, which could lead to corrosion and destruction of the foundation. Filling is not done to the very top. It is necessary to leave a gap of 10 cm. It is filled with a dry mixture, which can be purchased ready-made.

The next step is to install the head on the pile. It must be located on a horizontal surface. The purpose of the head is to hold the grillage on which the walls will be fixed. The head is welded to the pile so that the fixation is as reliable as possible.

Welding seams are cleaned and coated with paint, which will protect them from corrosion. A video of the complete process of constructing this type of foundation is below.

Resume

As you can see, a columnar foundation is a fairly common design. It is an indispensable option when it is planned to build a small lightweight building. The last one can be a rounded log or frame. When laying the foundation, it is important to take into account all the features of the soil, as well as other parameters that were discussed in the article.

The foundation is the support of the entire house; the durability of the entire building depends on its design and strength. When choosing the type of foundation for country houses, our compatriots play it safe and lay a strip foundation. You can easily verify this by taking a tour of the gardens. But such measures are completely optional. For light buildings, such as wooden, frame, frame-panel houses, a column-type foundation is more suitable. In addition, indications for its use are soils supersaturated with moisture, sandy soils, peat, swampy soils and those where frost heaving forces can push out or damage the strip foundation. You can build a columnar foundation with your own hands in an extremely short time, without involving heavy equipment and a team of workers.

A columnar foundation consists of pillars - supports buried in the ground and protruding outward. The top level of the pillars must be the same. A grillage is installed on top of the pillars to connect the supports and distribute the load evenly. The pillars must be placed at each corner of the building, as well as at the intersection of walls and in places where the maximum load is applied.

The material for the pillars can be wood, brick, concrete, concrete blocks, asbestos-cement or metal pipes, as well as rubble stone.

Wooden pillars Today they are used extremely rarely, as they are short-lived. But under light wooden buildings or terraces it is quite acceptable to install a columnar foundation made of wooden posts. The diameter of such pillars should be 0.15 - 0.2 m. Before burial, they must be treated with special preparations and impregnations that prevent rotting and prevent combustion. Bitumen mastics can be used as a waterproofing material.

Iron ore brick, fired in a kiln, is used for shallow or non-buried columnar foundations. The width of the pillar must be at least 0.38 m.

Concrete reinforced pillars are the most common and reliable option for a columnar foundation. They can be either monolithic or constructed from ready-made concrete blocks. The width of the pillars should be 0.4 m.

Asbestos-cement or metal pipes are used for arranging pillars as permanent formwork, since reinforcement is inserted inside them and concrete is poured.

Depth columnar foundation is calculated depending on the structure of the soil, the level of groundwater and the level of soil freezing. A foundation buried 0.4 m into the soil is considered shallow. Recessed - immersed 0.15 - 0.5 m below the freezing level.

Very often, a columnar foundation is installed in areas where the soil freezes 1.5 - 2 meters deep, since the construction of a strip foundation in this case is simply unprofitable. The lower level of the column is buried 15 - 25 cm below the soil freezing level.

The distance between the pillars can be from 1 to 2.5 m, but spacing more than 3 m is not recommended.

As grillage you can use a strong beam. If the structure is wooden, then it will act as a mortgage crown. But monolithic concrete grillage poured into wooden formwork is gaining more and more popularity.

The grillage of a columnar foundation can be high (above 35 - 75 cm above ground level) and low (lying on the ground).

A very important design feature of columnar foundations is that it is impossible to install a basement in the house. Sometimes, to enclose the space between the pillars, a fence is formed, which is smoothed out of brick or stone, but is not connected to the foundation pillars, so as not to disrupt its integrity in case of movement. It is very important to arrange ventilation in the enclosure to ventilate the underground space. But collection is not always done. In frequently flooded areas, columnar foundations are erected to a high height above ground level, which can range from 1 to 2 m. In this case, the house remains completely “hanging” in the air on pillars.

Columnar foundation: drawing, calculation and diagram

Before starting any work related to the construction of the foundation, it is imperative to stock up on design documentation. It is better to entrust the creation of this documentation for the house to special architectural companies.

The columnar foundation diagram looks something like this:

The first step is to calculate the columnar foundation to determine the number of pillars, their material, laying depth, arrangement locations, width, and more. Calculations will require soil characteristics, groundwater level, frost heaving forces, soil freezing level, building material, its height and number of storeys, type of floors, roofing material, loads at each key point of the building, and more. For independent calculations, there are corresponding online calculators on the Internet for calculating columnar foundations.

All dimensions obtained for a columnar foundation are entered into the design documentation, where all characteristics, material and much more are indicated.

DIY columnar strip foundation

Recently, the so-called lightweight foundation for modern one- and two-story cottages has become popular, which consists of pillars buried below the freezing level of the soil, and a non-buried strip foundation connecting these pillars. It won’t be easy to make such a foundation yourself; it’s better to call friends for help and order a ready-mixed concrete mixer to make the structure durable.

Earthworks

Before making a columnar foundation, it is necessary to prepare the site for construction. To do this, remove excess soil and eliminate unevenness. If the top soil is clayey, you will have to remove most of it and fill it with sand.

Next, you need to mark the area. Using construction thread, we mark the site according to the attached drawing. We stretch the thread in two lines parallel to each other, with a distance equal to the thickness of the future strip foundation. We control the angle of intersection of the threads and the angles of the future structure; they should be equal to 90 °. We mark the places of intersection and junction of walls, as well as the corners of the building, places with the greatest load.

Throughout the marked area, we remove 30 - 40 cm of soil where the strip foundation will be. We make the width 7 - 10 cm larger so that there is room for the formwork.

According to the drawing of the columnar foundation, using a hand drill we make holes where the pillars will be. The diameter of the hand drill is 150 mm, 200, 250, 400 mm. If the depth of the pillars does not exceed 1 m, then additional fixation of the walls from crumbling is not necessary. If the depth is greater, then you will have to form supports from boards so that the soil does not crumble.

We fill the bottom of the wells with sand, a layer of 10 cm.

For the last time, we check the location of the wells along the axes and the evenness of the future foundation.

Arrangement of pillars

We will use concrete to construct the pillars, but to waterproof it, we will use a little trick.

From roofing felt, twisted in two layers, we form a pipe of the required diameter. We glue the connections with tape, and also tape the pipe around the circumference. We insert the structure into the well until it touches the ground.

We knit and weld a reinforcing frame from a reinforcing rod 10 - 14 mm in diameter and 6 mm wire. We insert it into the well. The top of the rods should protrude from the well by at least 15 - 25 cm.

We begin to fill the pillars with concrete. To do this, first pour 20 - 25 cm inside the well and lift the roofing felt pipe so that the concrete below spreads and forms a base. Then we fill the hole completely with concrete, forming a pillar. Using an electric deep vibrator, we shake the concrete so that there are no air bubbles or voids left in it.

While the concrete in the pillars dries, let's work on the strip foundation.

Arrangement of a lightweight strip foundation

We weld and knit a frame from reinforcing rod and wire to reinforce the strip foundation. Be sure to weld it and screw it to the rods sticking out of the pillars.

The rods will be located along the foundation strip, and the wire will be reinforced in the transverse direction, forming horizontal jumpers.

We install the formwork for the strip foundation. To do this, we use boards 10 - 15 cm wide and 4 cm thick. Instead of boards, you can take chipboard, plywood or iron sheets. When the formwork is knocked down, we lay waterproofing material inside. It is best to use modern membranes or polyethylene film, which will also be needed to ensure that concrete does not spill out of the formwork through the cracks.

We fill the strip foundation with concrete. For simplicity, it is better to order a mixer machine to fill such a large space. We also shake the concrete with a vibrator. When the concrete gains its strength, after 20 - 28 days, the formwork can be removed and all the necessary work on waterproofing the foundation can be carried out. Then we fill the remaining trenches with soil.

For more information about how such a strip-column foundation is made, watch the video:

Important! Many experts are extremely negative towards columnar-strip foundations, insisting that the foundation should be either columnar or strip. Only in this case will it fully perform its functions and not interfere with movements in the ground. Despite this, many construction companies continue to equip a combined foundation. So it's up to you to choose.

DIY columnar foundation

For comparison, let’s consider the option of arranging a purely columnar foundation with a high grillage. Its arrangement is advisable for light buildings on sandy soils.

Earthworks

We mark the site, as in the first option. Then we remove fertile soil from the site by 15 - 25 cm. In the corners and places where walls intersect, we drill wells 0.6 m deep. Better yet, we dig square-shaped pits in the place of future pillars by hand.

At the bottom of each pit under the pillars we pour a layer of concrete 10 - 15 cm. It will serve as a cushion for us. When the concrete has dried, you can begin to form the support pillars.

Construction of a columnar foundation

For the pillars we will use iron ore brick, carefully baked in a kiln. We lay out a support pillar with a width of 38 cm and a height of 35 - 45 cm above the ground level using brickwork. The bricks can be placed in a closed loop, leaving free space inside. Inside the empty space we form a reinforcement frame, tie at least 1 - 3 rods and insert them. Then fill it with concrete.

We check that the pillars are at the same level. Once the concrete has dried, the pillars can be waterproofed.

We fill the trenches with soil. We arrange a grillage on top of the pillars. It can be done using wooden rand beams. The edges of the beams must necessarily rest on the pillars and be connected to each other with a tongue-and-groove joint.

The grillage can be made of concrete. Then it is necessary to install formwork from wooden boards, weld a frame made of reinforcement inside and fill everything with concrete.

Columnar foundation technology allows you to make pillars from asbestos-cement pipes. They are lowered into the well, then concrete is poured inside. Raise the pipe so that the concrete spreads, and then add concrete further, not reaching 10 - 15 cm from the top of the pipe. When the mortgage crowns of the house are connected to the foundation, they will need to be secured to the pipes using anchors and corner joints.

The construction of a columnar foundation allows you to significantly save on materials and a team of workers, since all work can be completed independently in a matter of days. Such a foundation can be safely built for wooden houses, bathhouses, technical buildings, terraces, verandas, gazebos, garages and other buildings whose weight is not enough to load the strip foundation. By the way, if you built a columnar foundation in the fall, it is not advisable to leave it unloaded for the winter. Therefore, concrete slabs are installed on top or they try to build the entire building before the onset of frost. Otherwise, during the winter, the forces of frost heaving may push the pillars out of the ground, and their location will no longer be even. It will be easier to dig them up and make a new foundation than to correct the consequences.

Construction of a columnar foundation

Types and purpose of columnar foundation

Construction of a columnar foundation with varying degrees of depth

Basic designs of columnar foundations

Do-it-yourself columnar foundation step-by-step instructions

1. Preparatory stage

2. Marking for supports

3. Construction of a columnar foundation

4. Waterproofing works

5. Pickup

Conclusion

Types of columnar foundation by depth

Columnar foundation design

Step by step instructions

Geological surveys and calculations

Marking and excavation work

Preparation

Reinforcement

Widening the pillar

Formwork

Drainage and waterproofing

Backfill

Benefits of the solution

Types of designs

Varieties by depth

Basic Concepts

Self-calculation

Construction process

Monolithic option

With brick pillars

Pile option

Resume

Columnar foundation: drawing, calculation and diagram

DIY columnar strip foundation

Earthworks

Arrangement of pillars

Arrangement of a lightweight strip foundation

DIY columnar foundation

Earthworks

Construction of a columnar foundation

Do-it-yourself columnar foundation: video instructions