Rafter roof of a frame house. Types of roofs for frame houses and do-it-yourself installation. Internal partitions of a frame house

The roof structure of a frame house is one of the simplest, so its independent construction will not take much effort and time.

This article will help you if difficulties arise during the work. In it, we will look at the features of roof installation, give practical recommendations on the choice of material, structural elements, and compliance with the necessary standards and requirements during the work process.

What to do before starting work?

Before starting construction, you need to decide:

With roof type and slope angle
Type of roofing material
Length, cross-section of rafters and distance between them
Length, pitch and cross-section of sheathing and counter-lattice elements
Type of insulation

Type of roofs of frame houses

Roofs are:

Flat
Pitched (with one, two or more slopes)
Attic (with two and four slopes)
Pincer, conical, multi-pinion, etc.

The choice of roof is made not only based on the conditions of its appearance. It is important to consider the functionality of the design. The main advantages and disadvantages of different types of roofs are given below.

Frame house with flat roof

Flat roofs are not popular in private construction. Their construction does not cause difficulties, but the shortcomings cover everything. They require careful care. After rain, water remains on the roofs, and in winter you have to remove the snow yourself. This increases the likelihood of moisture penetrating into the room. On houses with a pitched roof, you can use the attic as an additional room.

But when installing a flat roof, you can significantly save on building materials and sunbathe on it in the summer.

During installation, it is necessary to maintain a slope angle of 2-3 degrees relative to the horizon.

Multi-pitched and single-pitched roof of a frame house

The slope angle of the slopes starts from 10 degrees. The number of slopes is from 1 to 4.

Pitched roofs are very popular and are used everywhere. In the spring, snow does not linger on them for a long time, water calmly flows down the gutters, and a lot of additional space appears in the form of an attic space, where you can arrange an additional room. The load on the structure is also reduced, and along with it the possibility of leaks.

Mansard roof

It can be semi-hip (double slope with two small slopes) and hip (four slope). This type of roof is also widely used.

The advantages are as follows: additional space under the roof, the ability to install windows, a unique appearance of the house, low load on the structure in winter. Disadvantages - high costs for materials, heating, a lot of snow on window structures in winter, faster destruction of rafter structures due to insufficient ventilation.

Multi-gable roof

The multi-gable roof is considered one of the most popular. It differs from others in the large number of slopes and the presence of valleys. Installed if the house has a complex layout.

Advantages - the design can withstand significant loads, it becomes possible to equip an additional room, and a unique appearance. Disadvantages: high consumption of material, leaving a lot of waste, difficulty in DIY installation, and high financial costs.

Conical roofs

A conical roof is installed when the building is made in the shape of a circle. In Russia, few people build such roofs.

Advantages: interesting appearance, ease of maintenance. Disadvantages: complexity of calculations and installation.

We suggest choosing a roof with two slopes. In this case, it will be possible to significantly reduce the costs of materials and maintenance, while the appearance of the structure will not be affected.

It is worth understanding that the more slopes, the more beautiful the roof, but at the same time more expensive. But if you are not used to saving and want the best, then install a roof of any type.

Slope slope

The ideal slope for safety and durability is a slope of 30 to 45 degrees. In this case, the load on the roof (wind, snow) is optimal.

At the same time, externally, a roof with such a slope looks more advantageous.

Choosing roofing material

The choice of roofing material depends on the slope of the slopes. In this case, the necessary safety requirements will be met and the service life of the roof will be increased.

Below are the main types of roofing materials and the slope angle that must be observed during installation:

Corrugated sheeting – from 10 degrees
Slate - from 12 to 60 degrees
Euroslate (ondulin)– from 6 degrees and above
Ceramic tiles– 18-60 degrees
Polymer sand tiles– 18-60 degrees
Bituminous shingles– from 12 degrees without limiting the maximum slope
Metal tiles– from 15 degrees

When choosing the type of roofing material, you must follow the following recommendations:

The material must match the roof configuration
The service life of the material should be as close as possible to the shelf life of the roof itself
The selected material must meet the aesthetic and economic criteria of the owner. It is necessary to take into account the complexity of the masonry and the cost of the roofing material, the complexity of the roof layout, etc.
The roofing material must have the most “advantageous” characteristics: durability, resistance to mechanical and climatic influences, ease of maintenance, frost resistance, level of sound insulation, climatic conditions, etc. If you live where it hails frequently, you shouldn't choose a roofing material that will turn into rags after the first rainfall.

Rafters: section, pitch, length

To calculate rafters, you can use a special calculator, saving time:

The cross-section of the rafters is selected taking into account the following parameters:

Lengths of rafter legs and pitch of their installation
Roof slope (the smaller it is, the less load on the surface)
Loads (snow, wind, etc.) that are established in regulatory documents for each region of the country
The type of material that will cover the roof, as well as its weight and size

You can select a section in two ways: refer to construction tables or carry out an independent calculation.

We suggest that you familiarize yourself with the standards given in the table below. However, it is always better to choose the option with a reserve. From the table you can immediately select the rafter pitch and length.

Rafter installation pitch, mm	Length of individual rafters, m
Rafter installation pitch, mm	3,0	3,5	4,0	4,5	5,0	5,5	6,0
600	40x150	40x175	50x150	50x150	50x175	50x200	50x200
900	50x150	50x175	50x200	75x175	75x175	75x200	75x200
1100	75x125	75x150	75x175	75x175	75x200	75x200	100x200
1400	75x150	75x175	75x200	75x200	75x200	100x200	100x200
1750	75x150	75x200	75x200	100x200	100x200	100x250	100x250
2150	100x150	100x175	100x200	100x200	100x250	100x250	_

Lathing

Depending on the slope of the roof and the roofing material (in this case, tiles were chosen), you can select the pitch and dimensions of the sheathing according to the table.

The cross-section of the step lathing bars can be selected as 50 by 40 mm.

Roof slope, degrees	Lathing pitch, mm	Consumption of tiles, pcs/m2
50	375	8,9
45	370	9,0
45	365	9,2
40	360	9,3
35	355	9,4
35	350	9,6
30	345	9,7
25	340	9,8
20	335	10,0
15	330	10,1
14	320	10,4

Counter-lattice

The size and cross-section of the counter-lattice can be made the same as that of the sheathing.

The pitch should match the pitch of the rafters.

Installation of the roof of a frame house

The installation sequence for a gable roof is as follows:

Installation of the rafter system
Laying insulation
Arrangement of lathing and counter-lattice
Installation of roofing material and finishing structural elements

Installation of the rafter system

Installation of rafter legs begins after the ceiling beams (mauerlats) are securely fixed. The rafters will be a beam with a cross section of 50×150 mm, or 50×200 mm. Take a more accurate cross-section from the table above.

Preparing the rafters

First you need to make a template for the rafter legs. This is done like this:

Take two boards and overlap them at an angle of 90 degrees, fixing them with a nail at the top point
The template is lifted up and the edges of the boards are installed on the mauerlats
By adjusting the arrangement of the boards, the desired slope is found. At the same time, their edges should extend 40-60 centimeters beyond the level of the walls, to make it easier to install a drainage system in the future. If the length of the boards is not enough, you can sew two on the ground
When the required slope of the slopes is obtained, it is necessary to nail a crossbar between the rafter legs, thereby fixing the angle. At the same time, you need to mark with a pencil the cut line of the rafters if they will be fixed end-to-end and cuts at right angles in the places where the legs are attached to the mauerlats
All calculations must be made with maximum accuracy

After the template is prepared, you need to use it to assemble two pairs of rafters, which will be mounted along the edges. If necessary, the legs are extended. They can be joined halfway across the tree using thick bolts, which is safer, or using two nails driven in at different angles. A cross member must be installed between the two legs of one rafter.

Timber splicing

Overlapping rafter connection

Splicing rafters using the butt joint method

Twin rafters

Rigid connection with a steel angle and a supporting sheathing beam

Driving nails from the sides, at an angle towards each other

Sliding connection of rafters

The next step is to lift the rafters onto the roof and fix them on the mauerlats (beams), as shown in the picture. A thrust block is mounted below.

When two pairs of side rafters are installed, you need to stretch the rope between them. It serves as a beacon by which the level is checked. Next, the distance between the rafters is measured and divided by 60 or 80, depending on the step with which the installation will be carried out.

After the calculations, the required number of rafters is assembled on the ground. Then they rise to the top and are installed with the selected step along the entire perimeter. Two boards are nailed between the trusses for fixation.

Insulation of the roof of a frame house

To avoid freezing in winter, you need to insulate the roof.

First, a vapor barrier film is attached to the inside of the rafter legs using a construction stapler. The joints are sealed with double-sided tape. Then insulation boards are laid in the space between the rafter beams.

To protect the insulation from precipitation, you need to lay a diffusion membrane on top of it. If you plan to use reinforced film, then leave a gap of 2 centimeters between it and the insulation.

Here's a great photo that makes the process easier:

1 - Rafter
2 - Insulation
3 - Under-roof wind-water insulation
4 - counter rail
5 - Lathing
6 - Roof covering

Lathing and counter-lattice

The counter-lattice can be made with bars 25 by 30 centimeters or 30 by 50. The spacing of the bars is the same as that of the rafters, since they are mounted on top of them. This is clearly visible in the photo above.

The sheathing is mounted on the counter-batten. For this, boards 25 by 100 mm, or beams 40 by 50 mm are used. The sheathing pitch depends on the type of roofing that will be used. Fastenings are made with galvanized nails, the length of which is three times the thickness of the bars or boards and in a checkerboard pattern.

In the photo below, select the desired distance for your option.

Installation of roofing material

In our case, we will consider the installation of metal tiles. It starts from bottom to top.

First, the cornice strip is installed using self-tapping screws. Next, the first sheet of metal tiles is lifted onto the roof. It is attached to the cornice strip with self-tapping screws in each recess. Then you can attach the sheet through one notch. If the length of one sheet of tile is not enough, you can extend it using free pieces, laying them overlapping and fixing them with 4.8 x 28 mm self-tapping screws. Next, the remaining sheets are laid in a similar manner with an overlap.

The bottom edge of the tiles should protrude 40 cm beyond the edge of the eaves.

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Classmates

Frame houses are very popular not only because of the simplicity of the foundation and the easy installation of walls and floors.

They are warm and cozy for a comfortable stay.

At the same time, the natural wood materials used in construction are highly environmentally friendly and absolutely harmless to human health.

rafter legs;
Mauerlat (beam laid on the walls of the house to which the rafters are attached);
skate;
sheathing;
supporting elements.

There are basic, or basic, types of rafter systems depending on the technology of the device:

layered rafter systems;
hanging rafter systems.

Layered

The layered system is used in buildings where load-bearing walls serve as internal partitions.

It becomes much easier to arrange such a structure due to the fact that in addition to attaching the rafters to the Mauerlat, additional supports are created at the points where the load-bearing walls pass.

Thus, three or more support points are obtained - two external walls of the frame house and internal support points. In addition to the overall load resistance, this method makes it possible to reduce the cross-section of structural elements. The advantage of the possibility of creating a layered system is undeniable in those places where there are gusts of strong wind and large amounts of snow in winter.

The advantages are:

reducing the load on the rafter legs;
increasing resistance to external factors;
ease of installation, despite the apparent clutter of the structure.

Minuses:

at the middle point of support - it is impossible to arrange an attic in the attic space;
cost when purchasing more material to create a frame.

Hanging

The hanging rafter system in frame houses is used in structures with a maximum length of 6 meters.

In this design, the rafters at the lower point rest on the mauerlat laid on the load-bearing walls, at the upper point they rest on the ridge girder.

However, with such a basic structure, the rafters place a significant load on the mauerlat and load-bearing walls as a result. To reduce such loads, bolts and tie rods are used. If it is necessary to span spans longer than six meters, it becomes necessary to install supporting elements in the form of struts and vertical posts.

The construction of not only the roof, but the entire house begins with the foundation. When choosing one or another method of its formation, you should keep in mind all the features of the construction of walls and rafter systems to adequately withstand loads.

Advantages of a hanging rafter system:

large attic space;
lightweight design;
lower financial costs.

Minuses:

increased load on rafters, external walls and foundation;
increasing the cross-section of structural elements and weight.

Farms

In addition to the systems discussed above, combined designs are also used that combine the features of the two systems.

These are the so-called roof trusses. Their installation is required when there is a need to cover large spans.

Most often, such systems are used in the manufacture of attic sloping roofs.. At the same time, an attic frame is made, in which the vertical posts will form the walls of the attic, and the upper horizontal beams will serve as the junction of the upper and lower parts to the roof slope. The cross beam connecting the upper ends of the racks acts as a crossbar and serves as a tightening for the top.

The combined system is more complex in design than the layered one, however, the lack of need for middle supports and the possibility of arranging a cozy attic pays off all the laboriousness of the process.

Step

The distance between the rafter legs depends on various factors, which include:

permanent and temporary loads acting on them;
weight of roofing material;
cross-section of rafter system elements.

Reference: There are special tables and systems for calculating rafter pitches. As a rule, it ranges from 0.6 m to 1 m, depending on the combination of all factors.

Tools

When performing roofing work, it is advisable to have the following set of tools available::

Hacksaw.
Miter saw.
Chainsaw.
Jigsaw.
Hammer.
Pliers.
Drill.
Screwdriver.
Electrical extension cord.
Angle grinder.
Brushes for antiseptic treatment.
Nails, screws, wire, fastening mechanisms.

Safety precautions

When carrying out roofing work with your own hands, you must remember and strictly follow safety precautions. After all, attaching a roof to a frame house is considered not an easy procedure.

It should be borne in mind that the causes of injury can occur in two cases::

falling from a height;
objects falling on your head.

For this reason, it is necessary to have a protective helmet on your head and wear a safety belt. The belt should be secured using a safety rope to the structural parts of the roof.

Important: such work should be carried out during the day, and if necessary, the work area should be well illuminated.

Device and installation

Gable

The traditional version of this design is considered to be symmetrical gable roofs with straight slopes with an optimal slope angle of 40-45 degrees.

It is this design that is most designed to withstand natural loads in the form of wind and snow. At the same time, the gable roof of a frame house can be installed very quickly with your own hands.

Important: Depending on the intended use of the attic space, there are: roofs with a heated and unheated attic.

For a heated attic, additional work must be carried out to ensure its reliable insulation.

Insulation of the roof of a frame house is necessary in the case of a heated attic, attic or second floor. The structural pie of such a roof will look like this::

roofing material;
a layer of moisture and wind protection on top of the rafter legs;
a layer of insulation between the rafters;
vapor barrier material to prevent the formation of condensation and moisture on the insulation and wooden elements of the rafter system;
internal lathing;
internal finishing lining.

In fact, insulation of the roof and walls of a frame house is one of the fundamental factors during construction.

An unheated attic is easy to install. His pie contains no additional elements:

roofing material;
moisture and windproof film;
rafters

The installation of a hanging rafter system in a gable roof is no different from the method of such a device discussed above.

Let's consider its stages:

A Mauerlat is installed on top of the load-bearing walls on the top frame.
The cross section of the rafters is determined.
A ridge board is installed on temporary supports.
Rafters of the required length are made and attached to the ridge and mauerlat. To do this, the upper end of the rafters must be sawed off at an angle to connect to the ridge, and the lower end must be sawed off for installation on the mauerlat.
Rafter tie-downs are installed.
The eaves overhang fillets are attached to the lower end of the rafters.
The fillies are installed on the pediment and the wind boards are attached.
Cornice boxes are created.
The roof covering is being installed.
The eaves overhangs are hemmed.

Layered rafter systems in gable roofs of a frame house are made in the same way with the difference that they are additionally installed:

lying on the internal load-bearing wall;
support board from the ridge girder to the bed;
struts - from the support board to the rafters with perpendicular fastening.

Broken

When arranging an attic in the attic, it is recommended to make a special type of roof - a broken roof.

This way you can increase the usable attic space and maintain resistance to loads.

It is worth noting that, with some skill, a sloping roof for a frame house can be erected very simply with your own hands.

The structure of a sloping roof includes the following elements:

Mauerlat on the top trim of a frame house;
floor beams;
ridge run;
side purlins;
hanging rafters;
layered rafters;
puffs;
headstocks from the ridge run to the puffs;
racks from side girders to floor beams;
struts for fixing layered rafters;
sheathing;
roofing material.

Reference: The broken type of roof differs from the gable roof in the presence of two types of rafters, which require their own method of fastening.

Layered rafters are installed on the Mauerlat. It is customary to distinguish two methods of attachment to the Mauerlat:

hard (using a notch on the rafter leg, and the option of sewing a block as a support on the rafter leg);
sliding. It is used in cases where shrinkage of the house is expected. In these cases, special fastening mechanisms are used.

Installation of the roof of frame houses, including sloping roofs, is a complex undertaking that requires preparation. Nevertheless, the roof of a frame house can easily be built with your own hands if you approach this issue competently.

Only those who are well versed in the specifics of roofing work, know how to calculate possible loads and choose the right material, and have the skills to use construction tools can make a sloping roof with their own hands.

Let us highlight the following scheme for the construction of a sloping roof in a frame house:

Calculation of the rafter system depending on the dimensions of the building.
Calculation of the amount of materials for roofing.
Preparation of the material - treatment with antiseptics to prevent wood rotting.
Installing the Mauerlat on the top trim.
Preparing templates for making rafters. To do this, the shapes of the necessary cuts are created from thick cardboard on the lower part of the layered rafters.
Installation of floor beams. The outer end ones are placed first, then the intermediate ones. Then the rest according to the level.
The support posts are attached strictly vertically.
Horizontal purlins are installed. Attention! Support posts are installed on each beam.
Each pair of racks is connected by a tie.
Layered rafters with struts are installed.
In the center of the tie rods along the entire structure, a headstock is attached, which acts as a ridge girder.
Hanging rafters are attached from the side horizontal purlins to the top of the headstock.
The rafters are covered with wind and waterproof film.
The top sheathing is created.
The roof covering is being laid.

Depending on whether the attic will serve as a residential floor, its insulation depends. In the case of a residential attic, a layer of mineral basalt wool is laid between the rafters, a layer of vapor-proof membrane is covered, and an internal lathing is created. As a rule, wooden lining is chosen as the finishing material. Although, any options are possible.

Gutter

To drain storm and melt water, the final stage of roof installation in a frame house is the installation of a drainage system.

To do this, the following work is performed:

Hooks are attached to the bottom board of the roof sheathing at a distance of 0.8-0.9 m.
The hooks are installed in advance before the roofing is installed.
Calculate the angle of their inclination.
If necessary, make a hole in the gutter for a funnel.
Attach the funnel.
The gutters are laid in accordance with the markings and the position of the hooks.
The gutters are connected using clamps.
The ends of the gutters are plugged.
Drain pipes with elbows are connected to the funnels.

Useful video

Check out the rafter installation process visually in the video below:

conclusions

Reliable protection of the entire structure depends on the design and installation of the roof in a frame house.. You should do it yourself only if you are confident in the correctness of your actions. It is necessary to strictly adhere to regulated norms and principles. The strength and reliability of the structure depends on this.

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You need to decide on its type, which depends on the geometric shape and material of the roof. This article is devoted to the design and sequence of roof assembly using frame technology. Frame technology is universal for roofs of any shape and involves the use of any roofing material. To design a frame roof, the snow load of the area where construction is taking place and the dimensions of the building being constructed are taken into account.

The specialized literature contains many articles devoted to the shape of roofs, technical and economic aspects of construction. Our article will discuss in detail only the installation of a roof made of new material “ Shingles«.

So, what are the requirements for a roof assembled using frame technology?

Such a roof must ensure that the load (wind or snow) is transferred to the walls of the house, and it must also protect all the parts from which the frame of the house is made from precipitation (rain, snow, excess moisture). It is necessary to leave enough space under the roof for the installation of insulation, which will isolate the attic space from the warm rooms of the house, the attic must be well ventilated and ventilated, the roof itself and the roof frame must be well protected from the adverse effects of the warm part of the house (especially heat and moisture).

Basic requirements for the ceiling.

All further construction will depend on the correct calculation of the overlap. The construction of the roof frame begins with the ceiling. The parts of the floor are as follows: support beam, floor frame and flooring. The sheathing that is done on the ceiling is also the subfloor. The final finishing of the floor will be laid on it in the future. The figures below apply only to a wooden frame in which the distance between the floor beams is no more than 600 mm and the floor load is no more than 2.4 kPa.

So, the humidity of the boards should be no more than 19%. The deflection of the boards must have certain indicators - for a board 4.6 m long - no more than 12.7 mm (if the ceiling is covered with plasterboard) and 19 mm (if the ceiling is not covered with plasterboard). According to the standards, these are boards of such grades as selected, first or second with a thickness of 9.2 mm for the first case and boards of the third and fourth grade with a thickness of 1.4 mm for the second case. The ceiling is secured to the foundation using a support board, and between floors the ceiling is tied to the upper frame of the walls. The support board and the basement floor frame must have a cross-section of 38x89 mm.

Basic rules for the construction and design of a frame roof.

The maximum free span should not exceed 12.2 meters.

The largest distance from truss to truss (or between rafters) should not exceed 600 mm.

If the roof is assembled according to a truss pattern, then the size of the main frame elements correlates with the width of the spans and the magnitude of the load of the snow layer. The rafters themselves come in the following types:

free-standing;
rafters that support the load from the attic ceiling (the frame of its floors).

In the future, for convenience, we will call them free rafters and loaded rafters. There are special tables that determine the size of the required rafter section. Also, the parameters of the attic floor can be determined from the tables. The boards from which rafters and ceiling beams are made must have a section size of 38x89 mm. If heavy clay tiles are used as a roof, and the building has large attic windows, then it will be necessary to strengthen the roof frame or calculate the parameters as for loaded rafters. If the roof has a slope of less than 28 degrees (the full span is related to the rise as 1:4), then the calculation for loaded rafters is applied.

The table shows the minimum values for the thickness of the cladding, depending on the distances between the rafters or trusses:

It is important to note that all the parts that make up the roof must be securely and firmly connected to each other. In the construction of an attic floor, it is necessary that the rafters and beams rest securely on the wall. A rafter beam, called a mauerlat, can also serve as a support. From above, the rafters come to the ridge board and are connected to each other there. The proportions of the ridge should be as follows: its width should not be less than the length of the rafter support; The dimensions of the ridge board section itself are 17.5x140 mm, no less. It is better if the ridge board is larger in size than the rafter boards. When fastening the rafters to the ridge board, they must not be allowed to move. There must be a right angle between the rafters and the ridge board, as well as between the rafters and the mauerlat.

In order to attach the rafters to the mauelat, it is necessary to make a cut in it. The length of the support itself must be at least 38 mm. If ridge and valley rafters are used, then the length of the support is 50 mm, the boards from which they are made are at least 38 mm thick.

Between shortened rafters (spikes) and ridge or valley rafters, an angle of 45 degrees must be maintained with respect to the floor plane.

It doesn’t hurt to remind you that the roof is the protection of the external decoration of the walls from adverse weather influences, so the rafters should protrude beyond the walls by 400-500 mm, and for wooden walls this figure is even greater - 550 mm. The distance from the edge of the wall to all ends of the rafters should be the same. The free ends of the rafters are connected to each other using a special board called a roller. The connection of the roof bolster boards can only be at the end of the rafters. The bolster is made from boards with a minimum thickness of 17.5 mm, but usually the same boards are used as for the rafters.
If the roof slope is 1:3 or more, then the calculated roof span can be made smaller. This is achieved by using supports, yokes and additional supports for the ridge. Additional frame elements must be made from boards with a section size of no less than 38x89 mm.

If the roof slope is 1:4 or less, oblique struts are used. In such a roof, it is not superfluous to use additional walls to transfer the load from the rafters to the floor beams. In this case, it is necessary to install continuous struts under these walls between the floor beams. The maximum deflection of these beams when exposed to the calculated snow load should be 25 mm.

In the case when the beams from which the ceiling is made are not connected between opposite rafters, be sure to install additional ridge support (if the roof angle is 1:3 or less). If this angle is greater, such support is not necessary, provided that the joint at the bottom of the rafters is securely connected.

To attach various additional systems and communications, cuts and holes are made in the roof frame. The parameters of the cuts (their sizes and position) meet the requirements for the floor frame.

The sheathing of the roof frame can be made of plywood, boards, chipboard and other materials. Their thickness depends on the distance left between the rafters. If sheet materials are used, their thickness should correspond to the support of the edges on the wooden roof frame. The sheet materials used in construction can significantly improve the appearance of the roof. In addition, they can strengthen the entire frame structure. Of course, when using such materials, it is important to follow all the basic rules for the construction of a frame roof. From many years of construction experience, the following are the most successful materials for sheathing: fiberboard (especially grade P-3), DSiP, not sanded or having a phenol-formaldehyde base. In addition, DSiP has a higher fire resistance rating in relation to boards and plywood.

With a distance between the rafters of 300 mm, the thickness of the cladding is as follows: plywood - 7.5 mm; DSiP - 9.5 mm; board - 17 mm. At a distance of 400 mm, the thickness of the plywood is 7.5 mm (all edges with support) and 9.5 mm (between rafters without support), the thickness of DS&P is 9.5 mm (all edges with support) and 11.1 mm (between rafters without support), board thickness - 17 mm. With a distance between the rafters of 600 mm, the thickness of the plywood is 9.5 mm (all edges with support) and 12.5 mm (between the rafters without support), the thickness of the DS&P is 11.1 mm (all edges with support) and 12.7 mm (between rafters without support), board thickness - 19 mm. These are the minimum indicators.

The attic space, located between the insulation and the roof sheathing, must have ventilation holes. Good ventilation allows you to preserve all the properties of the insulation and prevent the adverse effects of moisture and heat on the premises themselves in the building, frame and roof.

The size of the ventilation holes depends on the area of the insulation carpet and must be at least 1/300 of the insulation area on the attic floors. With a roof slope angle of 1:6 or less, the area of the ventilation holes should be 1/150 of the insulation area. Half of the ventilation holes should be placed near the ridge, the other half in the soffit. The distribution of ventilation holes along the soffit should be uniform. A distance of at least 75 mm must be left between the insulation and the sheathing. If this rule is difficult to implement, then special screens are installed between the insulation and the sheathing.

The opening to the attic must be closed with a hatch and have a size of 500x700 mm (no less). The hatch should be located in such a place that there is a distance of more than 600 mm between it and the nearest rafters. The hatch needs to be insulated. Foam plastic (thickness 100-150 mm) is usually used as insulation material.

The roof itself on frame-type roofs is made from a wide variety of materials. In this article we will describe a material that is widely used in North America and is called "Shingles". Translated into Russian, this word means “shingles.” The basis of “Shingles” is different - wood, metal, etc. To reduce the cost of roofing in economy-class buildings, this material is used on a bitumen base, which has a coarse-grained bedding (such as roofing felt). The main advantages of this material are high manufacturability, durability, and aesthetic appearance. In Russia, “Shingles” is already widely represented in construction stores and is beginning to be manufactured in its own production facilities. This material can be used to cover roofs with a slope of 1:6 or more.

In special construction tables you can find information about the required number of nails for assembling rafters and floor beams. When forming connecting nodes, it is not necessary to create additional wind connections.

Now we will focus on the rafter diagram of the roof frame (its most important components).

There may be different distances between rafters and floor beams. They must connect at least 1.2 meters apart. The rafters and floor beams are connected using various nodes. Their other important function, in addition to connecting, is to provide the necessary space for laying insulation and creating space for free air circulation (attic ventilation).

Rafters and ceilings can rest either on the walls or on a Mauerlat board, which is installed on the floor beams.

Here are the mandatory rules for installing the Mauerlat boards: the second Mauerlat board should stand in the same way as on the top frame of the walls, provided that there is a displacement of the rafter support towards the floor beams by more than 50 meters. The first Mauerlat board must be nailed (with two 82 mm nails) to each attic floor beam. Be sure to install the strapping board on the floor beams, especially if they are not directly connected to the rafters.

If the rafters and floor beams are located at equal distances, it is better to make a double connection unit. To do this, use a single Mauerlat board, and if the insulation is thick enough, additional support is placed on the top lining of the wall.

To connect each rafter to the ridge, at least three 82 mm nails are required on the reverse side and at least four 57 mm nails on the rafter side. The connection of the rafters and the yoke is carried out with three 76 mm nails. The position of the yoke must be strictly horizontal. The connection between a shortened rafter (spring) and a valley or ridge rafter should be made using two 82 mm nails.

The sheathing sheet material can be attached to the rafters in a similar way to the sheathing of the floor frame. The sheets are laid with a gap of at least 2 mm. If necessary, you can install support for the edges of the sheathing sheets. Usually this is a board with a section size of 38x38 mm. The rules for attaching it are the same as for floor struts.

If the roof frame is made of trusses, then the same rules and regulations are taken into account as when installing floor beams.

For the manufacture of large roofs, especially those with only two slopes, as well as roofs that have a large unsupported overhang, it is better to use trusses. For the construction of multi-gable and hip roofs, the rafter frame scheme is ideal. Both design schemes can be combined in one building.

Long-span trusses may eliminate the need for a mid-load-bearing wall. In this way, houses have a so-called free internal layout.

To make the roof structure lighter, as well as to reduce its cost, it is necessary to reduce the cross-section of the boards that are used for rafters and elements reinforcing the frame. For these purposes, better quality boards of the best grade are used. Also, for these purposes, the distance between the rafters is reduced and the load from the rafters is transferred to the load-bearing walls using various connection points.

When developing the connection between the rafters and the ceiling, it is necessary to provide space for the insulation sufficient for its free ventilation. In addition, it is important to correctly calculate the distance between the top of the window opening and the horizontal surface of the soffit.

The covering material is selected taking into account a certain angle of inclination of the roof.

When designing, it is better to specify the roof slope angle in degrees. In this case, you will not need to calculate the dimensions of the ridge rise.

When installing a roof over an attic room, it is better to calculate the characteristics of the rafters based on the strength characteristics. In this case, it will then be possible to complete an additional structure in which the insulation will be placed and sufficient ventilation will be ensured.

The boards for the rafters must be selected taking into account the possibility of their further strengthening (if the attic will be used) with the help of yokes. It is strictly forbidden to transfer the load from the rafters to the floor beams, which are located freely in the span.

To give the roof a beautiful shape, designers strive to create the same slope for all surfaces. It is not always justified to use expensive, durable materials for roofing. It has long been calculated that even the most durable material requires periodic repair. Therefore, sometimes it is more profitable to completely replace an inexpensive coating than to constantly repair the old one.

Recommendations for the correct assembly of the roof truss frame (basic techniques and rules).

Once the attic floor is installed, you can begin to install the roof rafter frame. What are the basic installation techniques?

1. The construction of the frame begins with the installation of a Mauerlat board to ensure an equal span along the entire length of the house. In the case of a multi-gable roof (this happens on houses with a complex plan), the Mauerlat is mounted simultaneously over all extensions. The joints of the boards must coincide with the floor beams. In the corners of the house, additional load on the walls of the house is transferred by ridge and valley rafters through additional supports under the Mauerlat board.

2. Rules for the location of spacer boards and floor beams. The rafters are located at the same distance as the pitch of the floor beams. Spacer boards must be nailed to each floor beam with two nails. If you move the Mauerlat board slightly relative to the outer wall, you can change the span distance, but not more than 30-50 mm. This way you can adjust the span throughout the house to a single value. If the roof is multi-gable, then the span value is allowed to be different for each extension. In this case, each span will require its own calculation of the length of the rafters.

The proposed method of assembling and installing the roof frame has one very important advantage - all calculations and preliminary preparation of individual parts can be carried out on the ground. You only need to know the size of the spans from the outer edge of the Mauerlat board and the length of the roof itself, which is also measured from the Mauerlat.

The proposed project includes a given roof slope angle. The half span value has been calculated. Therefore, using the cosine of the roof slope angle, you can calculate the length of the rafters. Based on the type of wood, snow load and distance between the rafters, the tables can be used to determine the cross-sectional area of the rafters. The next stage is making a rafter template from the straightest board. Also, using special tables depending on the length of the rafters on the angle of inclination of the roof, we make an oblique cut at the junction of the rafters and the ridge and make a notch with a wedge so that the rafter can be connected to the mauerlat.

Then you need to calculate how far the rafters will extend beyond the outer wall (be sure to not forget about the thickness of the external wall finishing according to the project - if the finishing is done with brick, then if there is an air gap, this figure will be equal to 145 mm). Using a square, you need to mark and then make a cut parallel to the direction of the cut that connects to the ridge. So, the rafter template is ready. Using this template, rafters will be made for the gables and those rafters that are adjacent to the end part of the ridge board. To make a rafter template that rests on a ridge board, you need to reduce the main template by a distance equal to half the thickness of the ridge.

Ridge length is defined as the length of the roof minus the full span. In order to correctly mark the ridge, the board is placed on the floor beams along the entire length of the roof. In this case, from each end to the edge of the roof there should be a distance equal to half the span. The markings are made along the wide part of the board. The position occupied by the floor beams is transferred to it. It is also necessary to note the position of the rafters along with the floor beams. To do this, use the same principle as for walls and ceilings.

If valley or ridge rafters are used, then the span when using a triangle should be not 30 cm, but 42.7 cm while maintaining the same amount of ridge lift. This is due to the fact that they are installed at a smaller angle than conventional rafters. The length of the ridge rafters is also easy to determine. It is taken into account that the unit of their length is a multiple of the span, like that of a conventional rafter. If the ridge rafter, when connected, enters the intersection point of the axis of the ridge board and the rafter, then its length is shortened by approximately 30 mm.

The length of the rafters (or shortened rafters) is calculated based on the given span and the distance between the rafters. If the roof has the same slope in all places, then the cut of the shortening rafter will always be 45 degrees. This cut is very easy to make using an electric hand saw. Using trinometric functions, the amount by which the next rafter will be shortened is calculated. There are special tables of these values for distances between rafters of 400 and 600 mm.

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Classmates

A frame house needs a full-fledged roof, no different in functionality from any other, but not too heavy.

Excessive loads on the walls are contraindicated for a frame building, the load-bearing capacity is limited, and the need for protection from climatic and weather factors is no less than that of any other house.

Therefore, the requirements for, in addition to all the main points, include such as “lightness, low weight, low load on the walls.” At the same time, the roof design allows for weight reduction only with a concomitant reduction in the permissible loads on the roof; any lightening of the rafter system or insulating pie will entail losses in the protective properties of the roof. Let's try to figure it out how to lighten the roof as much as possible without compromising its performance.

Rafters are inclined boards that carry roofing material and ensure that the shape and angle of inclination of the roofing plane is maintained.

By analogy with the wall frame, the role of the rafters resembles the work of step racks.

The service efficiency of the entire roof largely depends on the angle of inclination.

Attention! The racks are strictly vertical, while the rafters have a certain angle of inclination.

Structurally, the rafters of a frame house are divided into two types:

Hanging. Such a system is supported by the lower ends, which is why the entire system, connecting at the top point, seems to “hang” over two points of support. This design has a strong bursting effect on the supporting walls, which needs to be compensated. Its role is played by the so-called. tie, board or beam connecting the lower support points of the rafters. If you imagine one row of rafters as an isosceles triangle, where the same sides are rafters, then the base of the triangle is the tightening that removes the pushing force.
Layered. This type of rafter has an additional support line located along the central axis of the building. Again using the analogy of an isosceles triangle, additional support is located at the point where the height meets the base. Large buildings have an additional load-bearing wall along the central axis, which, among other functions, plays the role of supporting the rafter system. The bursting force in this case is noticeably less, but does not disappear completely, so to reduce it, the so-called. transom, a horizontal strip connecting rafters at points located in the upper third of the length.

Elements

In order to correctly imagine the structure of the system, you need to be familiar with the terminology.

All elements of the rafter system have their own names, without knowing which the conversation will be very difficult.

The rafter system includes the following elements:

Mauerlat. This is a belt made of timber, located along the perimeter of the load-bearing walls and serving as a support for the rafters. A kind of analogue of the bottom trim of a frame house.
Rafter (otherwise - rafter leg). An inclined beam used to support roofing material. Its length is the distance from the lower cut of the roof to the upper meeting point or fracture edge of the planes.
Ridge run. A horizontal beam located in the upper axis of the transition of planes. It is the upper support for the rafters.
Rack. A vertical beam that serves as a support for the ridge girder. Relies on a bench or directly on the ceiling.
Sill. A horizontal beam located on the longitudinal axis of the building. Mounted on the ceiling or on an additional load-bearing wall. Serves as a support for the racks, and also connects to the Mauerlat, relieving the extruding lateral pressure on the wall.
Puff. A beam connecting opposite points of the mauerlat. An important structural element that serves to relieve thrust forces. Complete with attached rafter legs, it forms a truss.
Rafter truss. A structural element of the system that combines two opposite rafter legs, a tightening and reinforcing elements - crossbars, struts, rafter legs. It is located perpendicular to the longitudinal axis of the roof.
Strut. A structural element, additional support for the rafters, relieving the load from the weight of the roof and eliminating deformation of the material. Connects the upper third of the rafter to the base of the post or to the bed.
Crossbar (rafter tie). A beam connecting the rafter legs like a tie, but not at the base, but in the upper third (for long rafters, several crossbars are made, located parallel one above the other).
Lathing. Horizontal strips located on the slopes of the rafters, installed at a distance of several centimeters from each other, serving to tie the rafters together and directly attach the roofing material.

Types of roofs

For a frame house, all options for constructive solutions for the rafter system are available.

Used in construction:

. The simplest option. Essentially, this is a flat canopy, horizontally or obliquely (more often) located above the building. It is rarely used for residential buildings; it is more often used for utility or auxiliary buildings.
Gable (gable) roofs. This design has two inclined planes located symmetrically or asymmetrically along the central longitudinal axis of the building. At the ends there are triangular extensions of the walls - pediments. The most common option.
Four-slope (hip, hipped). The structure consists of four inclined planes that meet at one point (hipped roof) or have a ridge (hip roof). It is less common than gable, but has a number of advantages.
Broken (mansard) roofs. A variant of a gable roof, but each plane is additionally divided into two sections, one of which has a large angle of inclination (close to vertical), and the other is flatter. This design increases the space of the attic, making it possible to use it as a full-fledged living space.

Each structure has its own rafter layout, determined by the number of slopes, the angle of inclination, the presence of roof elements - windows, abutments, valleys and others. This has a direct impact on the method of fastening the rafters of a frame house.

Calculation

The procedure for calculating a rafter system is quite complex and requires a lot of data, the search for which may not be possible for an untrained person. A way out of the situation could be:

contacting specialists. They will calculate, but it will take time and money;
using an online calculator. There are many of these on the Internet; to obtain a more correct result, it is better to duplicate the calculations in several calculators;
using a calculation program downloaded to your computer. The option is not bad, but it will not be possible to check the result using several calculation options.

Calculation of the rafter system includes:

determination of the angle of inclination. An important quantity that determines many parameters - weight, wind and snow load on the roof;
rafter step. Distance between neighboring farms. Too large a step means excessive load on the unit, too small a step means high material consumption and high roof weight;
section of the rafter beam. Determined based on the length of the rafter leg, it allows you to correctly prepare and determine the required amount of material;
mass of the system. An important indicator because it reflects the load on the walls.

To simplify calculations, there are a lot of sources online that contain tables with ready-made values for the sizes, lengths and thicknesses of all elements. The fact is that counting accuracy down to millimeters does not make sense; a range of values of several percent does not play a significant role. Therefore, it is entirely acceptable to use ready-made data taken from a table specially compiled for this purpose.

Important! It is strongly not recommended to do independent calculations using formulas without special knowledge and training.

Manufacturing

Coniferous lumber is used to make rafters.

The material must be dried and seasoned, otherwise after some time subsidence of the planes, distortions, and cracks may appear.

Apply:

Edged board 40-50 mm thick(depending on the length), it goes to rafters, ridges, tie rods, crossbars, struts, etc.
Beam 100 by 150 mm(or 150 by 150 mm). Mauerlat, lezhen, etc. are made from it.

All connections are made with nails, screws, and reinforced with metal plates. The corner connections of the timber are made half-timber with obligatory reinforcement with metal plates and struts. Constant control of horizontal, vertical and parallelism of elements is required. The accuracy of rafter installation is controlled by a tensioned cord.

If necessary, the rafters are joined along the length at the point where the strut is installed. The connection is reinforced with a wooden boss no less than 30-40 cm long. For ease of work (if the dimensions of the building are not too large), trusses are pre-assembled and installed on the roof ready-made. This method simplifies the work; you just need to constantly monitor the position of each node.

Pediments

Gables are usually installed either before or after the roof is installed. This procedure is not suitable for a frame house. When making the pediment of a frame house, it is simpler: the outer trusses located in the planes of the end walls are sheathed on the outside with the same material as the walls of the house.

The result is frame gables that exactly match in size and shape to all other elements of the system and do not violate the geometry of the roof. They are not too heavy, are strong enough to withstand wind loads and can easily be insulated if necessary.

Mauerlat

Mauerlat in a frame house is an analogue of the lower frame of the wall frame. It plays the role of a connecting element connecting the rafters, walls and floor of the attic.

It is made of pine (most often) timber attached to the upper cut of the wall.

The frame is often the mauerlat of the rafter system. Half-timber corner joints, reinforced with struts and metal plates, ensure rigidity and immobility of the structure.

Useful video

Check out the process of constructing the rafter system visually in the video below:

conclusions

The manufacture of a frame house rafter system requires, in addition to general rules, maximum lightening of the structure while maintaining load-bearing capacity. This issue can only be resolved by using lighter and stronger materials and reducing the roof area. All other requirements apply in the same way as for ordinary buildings.

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Your warm and cozy home is almost ready. All that remains is to make the final push in the construction of the so-called box - to correctly design the roof of the frame house. As always, the work will seem very simple and you want to do it yourself, but this stage of work is the most difficult. Here you will need skills in many ways: correct calculation of loads, precise carpentry and considerable experience in working with roofing materials. Let's figure it out in order using step-by-step instructions.

Features of a roof for a frame house

Probably the only element of a frame house that is no different from a structure built from brick and concrete or on a log frame is the roof. After all, if the walls and floor were made using completely different methods and materials, then the roof of a frame house is built from the same materials and according to the same rules. The main functions of the roof are the distribution of wind and snow loads, as well as the ventilation of attic rooms or under-roof space.

Stages of constructing the roof of a frame house:

choice of form
accurate calculation of the design and required materials. Drawing up a rafter system project
marking the top strapping
rafter arrangement
roof insulation (attic floors are especially often insulated along the roof)
installation of sheathing and counter-lattice with waterproofing contour
laying roofing material, installing drainage and snow retention systems, hemming overhangs, cladding gables.

Roof shapes for a frame house

Shed flat roof

For a long time, such roofing systems were applicable only for outbuildings: garages, sheds. The lean-to option has always been considered economical and simple. Indeed, installing a pitched roof for a house is one of the easiest and cheapest. But the development of architectural thought, as well as the desire to comply with the fashion of European builders, brought this option to one of the leading positions in the construction of frame cottages. Shed roofs are used especially often in Finland.

A pitched roof gives your home a very high-tech look that will set you apart from your neighbors. But do not forget about a number of disadvantages of this design:

shed roofs are rarely made with a slope of more than 19 degrees, which leads to increased loads even from rain, not to mention the need for manual snow removal, because you will have to forget about rolling snow masses on your own.
There are practically no attic spaces.
poor resistance to strong winds (a large roof area leads to windage, and a small slope leads to blowing under the roofing material).
It will be necessary to ensure much greater strength of the rafter system due to the above disadvantages.
The main distinguishing design feature of shed roofs is the absence of a ridge, on which the rafters are connected in other types. Here the rafters rest on opposite walls. Otherwise, installation is no different from construction of any other form. Even when installing a 6x6 house with a pitched roof, you will have to think about splicing the rafters, because most lumber is 6 meters long. (and taking into account the slope, the length of the rafters in a house 6 by 6 meters is approaching 7 meters) Pitched roofs were most widely used in construction using Canadian technology. In this case, ready-made trusses or even roof sections are delivered to the site and mounted on the top frame.

Gable roof

It consists of two slopes from the ridge to the walls. The pediments are obtained in the form of two triangles. This is the most common system in Russia when building houses using any technology. Perhaps in recent years it has lost its leading position to hip or mansard sloping roofs, but over the many years of construction of only gable roofs, most houses will have this appearance for a long time.

Let's consider the main elements of the rafter system for gable roofs:

Mauerlat - the top trim along the walls of a frame structure.
rafters - support beam from the ridge to the frame.
crossbar - a beam that horizontally connects paired rafter legs.
purlin - a longitudinal board connecting all trusses.
tie (rafter) - a horizontal beam connecting the rafters along the mauerlat.
racks - vertical reinforcements of the system from the tightening to the rafters.
sheathing and counter-lattice.

This roofing system does not have the disadvantages of single-pitch options. The slope angle of the slopes is usually 30-45 degrees, which significantly reduces the load from wind and snow. With steeper slopes, the load from precipitation decreases, but the load from wind increases significantly.

There are 2 main types of rafter systems for gable roofs:

Hanging - rafter legs rest on the walls and ridge.
Layered - a vertical beam is placed under the ridge beam (it is necessary to have a Mauerlat in the middle of the house). In this case, the main load of the system falls on the central beam, and the rafters seem to pull the walls together, adding to the rigidity of the entire frame house. Quite often, ready-made trusses, designed and manufactured in factories, can be supplied with a wall kit. You can also contact construction companies that will offer you a calculation of the correct design, and possibly installation of a gable roofing system.

Gable-semi-hip or hip roofs

They are a more complex modification of gable roofs, where the slopes have a trapezoidal shape, and instead of vertical gables, two more slopes are mounted.

The main advantage of this design is its absolute resistance to wind loads.

New elements of this design include:

Sloping or corner rafters connecting the corners of the house to the ridge beam.
The main rafters that connect the walls of the house to the ridge beam.
Additional rafters - connect the walls of the house with slanted rafters.

Hip roofs are one of the most complex ones; you should not calculate them yourself. Entrust the calculation of the correct design to professionals or special programs. If you have enough experience in building gable roofs, you can install a hip roof yourself.

Hip roofs

They have a hipped roof. Each of the slopes has a triangular shape, and they all connect at one point. This design has the same advantages as the hip design: it perfectly resists wind loads, does not accumulate snow masses due to the significant angle of inclination, and is evenly heated by the sun.

The key disadvantage is its significant complexity (experience in the construction of hip roofs is required). There are no new elements in hip roofs, but there is also no ridge beam, so a more complex design is required. Most often, hipped roofs are used for two-story houses, since it is very difficult to create an attic or attic space under such a roof.

Broken gable roofs

With the development of frame construction, there was a sharp breakthrough in the use of this type of roofing. This is due to the fact that frame houses are most often built with attics. At minimal cost you can get almost double the living space. Broken roofs are also classified as technologically complex structures. This is mainly due to the use of both types of rafters: hanging and layered.

Main disadvantages

Complexity of design;
Complex insulation technology;
High demands on waterproofing;
The need to create ventilation of the under-roof space;
Expensive designs of roof windows.

As you can see, the choice of roof shape is also associated with drawing up a well-calculated project and marking the top trim. So you will have to complete the first 4 stages of installing the roofing system almost simultaneously. Particular attention should be paid to insulation and waterproofing of the roof. Most often, insulation is carried out along the ceiling of the first/second floor, but in the case of the construction of attic floors, insulation is carried out under the roof to save living space.

Insulation of the roof of a frame house

To insulate attic floors along the rafters, insulation based on mineral wool or spatula fiberglass is used. However, it is necessary to take into account that these materials lose their thermal insulation properties from excess moisture, therefore, when performing insulation, two processes must be taken into account at once:

prevent moisture from entering the insulation from the room;
ensure the removal of vapors and condensate from the thickness of the insulation.

The air temperature above the roofing material and inside the attic can differ greatly, so the formation of condensation is inevitable. How to avoid the harmful effects of condensation on insulation? It is necessary to observe the order of laying insulation and building membranes. The insulation “pie” looks like this:

internal cladding along the rafters (can be rough or finishing);
vapor barrier circuit;
rafters with insulation laid between them;
counter-lattice;
waterproofing or superdiffusion membrane (the use of a membrane eliminates the need to install a counter-lattice);
sheathing (its role can also be played by sheet material - for example, soft tiles);
roofing material.

Making the right “pie” and following the installation technology for each element will help solve problems associated with insulation along the rafters.

Stripe battens and counter battens

The concept of sheathing is purely conditional; it is the preparation of the base for installation of the finishing roofing material. Therefore, the sheathing can be made from edged boards or sheet materials (moisture-resistant plywood, OSB, chipboard). Its thickness is calculated depending on the angle of the slope and the distance between the rafters.

Flooring roofing material

The choice of finishing roofing material depends on the angle of the roof and the aesthetic preferences of the owner.

The following materials are available on the market:

profiled sheet
metal tiles
ondulin
onduvilla
soft tiles
ceramic tiles

Conclusion

After laying the finishing roofing material, the roof installation can be considered complete. There is still quite a lot of work that you have to do: sheathing gables, installing additional elements, hemming overhangs, bringing out chimneys and ventilation shafts through the roof and many others. But if you were able to master the construction of a frame house “under the roof” with your own hands, then you can definitely do this work. If you trusted the contractor, then in this case the information presented will certainly be useful to you.