Mineral wool is one of the best, simplest and most common materials for insulation and soundproofing walls and ceilings today, and is also known in several other applications. In addition, it is easy to mount, that is, you can independently carry out the insulation of the premises.
Many people do not know how to cut mineral wool correctly without disturbing its structure, in this article we will look at all the ways to properly cut mineral wool, as well as advise on the tools that are best suited for this.
What types of mineral wool are there?
Mineral wool is usually classified according to the principle of the material from which it is made. From this follows the conclusion that mineral wool made from different raw materials also differs in structure - fibers, and, accordingly, in the type of cutting. So there are the following types of mineral wool:
- Glass mineral wool. Consists of melted glass.
- Stone mineral wool. It is made most often from various melts of rocks.
- Slag mineral wool. The starting material is blast-furnace slag.
In fact, you should pay attention to the fact that sometimes mineral wool is harmful. This is due to the fact that it contains dust and phenol-formaldehyde resins. Therefore, it is necessary to treat this material selectively, although mineral wool cannot be classified as a human carcinogen.
How to cut mineral wool:
Mineral wool cutting can be carried out both independently at home and using various equipment. Cutting equipment mineral wool boards may be different. The issue is scale. Mineral wool cutting machine is suitable for serious and large scale - for enterprises, manufacturers, etc. But the knife for cutting mineral wool will become indispensable assistant in cutting insulating materials at home.
It is important that cutting mineral wool does not damage the fibers, so the equipment must be selected carefully. The cut must be even. At home, cutting mineral wool rolls (the so-called "50s") will be convenient with a cutting knife, but for large ones ("100s") a special hacksaw for heaters will be convenient. At the beginning, its price may seem unreasonably high, but it's worth it. It is important that the work is done properly. Circular cutting of mineral wool can be convenient. The machine for cutting mineral wool can easily cope with such a task.
How to cut mineral wool:
If you do not know how to cut mineral wool at home, we can advise you on excellent tools that are best suited for cutting mineral wool.
So, for cutting mineral wool the best thing fit good, a sharp stationery knife or a hacksaw, carefully cut the mineral wool in the right directions, for greater accuracy, you can draw lines with a pencil or cut directly along the ruler. The process of cutting mineral wool is somewhat similar to cutting foam, only you need to make a little more effort, pressing a little harder on the tool for cutting mineral wool.
What to do with scraps and remnants of mineral wool.
One of the solutions may pleasantly please many (especially firms and major manufacturers). Mineral wool scraps are not useless and can be useful to those who decide to insulate their walls and ceiling in a budget option. Scraps can be sold at a low price, and the demand for the product will be very high.
It is also possible to recycle scraps of mineral wool boards. In this case, with the help of special equipment, the remains of mineral wool boards are crushed to granules with the possibility of further recycling.
Today, a method has been developed to obtain special kind insulation - stone wool made from basalt. Twenty years ago, such mineral wool was used exclusively for the needs of the defense industry, and today this insulation is widely used for thermal insulation of any buildings.
The composition of mineral wool does not contain such harmful environment components such as acrylic and phenol-formaldehyde resins. It consists only of natural binders, therefore it is safe for humans. This heat-insulating material not only perfectly retains heat, but also allows you to create a reliable sound insulation of the premises. Mineral wool from basalt is becoming more and more popular and has already been tested by time, but people still have a lot of questions regarding technological issues, which we will try to focus on in this article.
How to properly fix the mineral wool?
In this case, it all depends on the type of insulation and on the type of structure on which the thermal insulation is mounted. Light grades of mineral wool are installed in frame structures by surprise Rigid mineral wool boards are fastened with special dowels or fixed using special adhesives.
When fixing by surprise, mineral wool is laid very tightly in a pre-assembled from slats and bars wooden frame. The thickness of the frame must match the thickness of the insulation. Between the slats they maintain an interval less than the width of the mineral wool by 1.5-2 cm, which does not allow the material to slip during operation. Mats are mounted starting from the bottom of the structure, and rolls - from above. In this case, solid pieces are laid first, and free space, for example, near doors or windows, is filled later.
Mineral wool of high density is often mounted without intermediate / support bars. It is completely wound up behind the frame and pressed against it without a gap. load-bearing structure, after which, for safety, they are fixed with dowels with wide hat, that is, the so-called "dish-shaped" dowels. In such a system, the frame elements are located on top of the insulation layer and press the wool against the wall, in addition, brackets that pass through the mats help to keep the insulation in place.
When using the bonded thermal insulation method (wet method), frames are not used at all, therefore, adhesive compositions must be used as fasteners. In this case, you will have to purchase a dry mix, but necessarily intended for gluing mineral wool insulation. Recently, polyurethane glue in cylinders has become more and more popular, which allows you to mount dense mineral wool to any base, including wood, metal, and polymer. This technology also involves the use of dish-shaped dowels. In more detail, we considered the features of gluing insulation in articles on adhesive compositions and wet insulation of the facade.
What is the best way to cut mineral wool?
It is recommended to cut heat-insulating materials from stone wool with a hacksaw or a sharp long knife specially designed for this purpose, the blade of which is serrated. In any case, the equipment must be well sharpened so that the fibers break out as little as possible. Many insulation companies offer their customers also cutting tool: knives about 300 mm long, as well as saws with teeth without divorce, about 60 cm long. In the absence of special devices for such purposes, kitchen bread knives with fine teeth and a wavy edge perform well. Thin soft slabs and mats (50 mm) can be cut with an ordinary assembly knife.
Mineral wool produced in rolls is best cut before unrolling. And mineral wool boards are taken out of packs and cut one at a time. It should be remembered that during the installation of thermal insulation, the insulation must fill the entire insulated space very tightly, therefore, allowances should be left before cutting: for plates - 0.5 cm; and for mats - about 1-2 cm.
Is it true that mineral wool must be protected from moisture and wind?
During the operation of insulated buildings, their walls, roofs and other structures should be protected from high atmospheric humidity and from blowing strong winds. Therefore, mineral wool insulation after installation from the outside is covered with canvases from a vapor-permeable moisture and windproof membrane. This allows you to prevent the penetration of cold wind and drops of slanting rain into the thickness of the wall. At the same time, water vapor from the internal space, passing through the walls through diffusion, will be able to go outside without obstacles.
The undoubted advantage of mineral wool is its vapor permeability, and this property should be used to the maximum. When installing mineral wool thermal insulation materials between bearing wall and a vapor barrier does not need to be laid with a heater, since such sealing will negatively affect the climate inside the building. The lack of artificial ventilation in this case will lead to an increase in humidity and the formation of condensate, which, in turn, will cause the formation of mold and fungi.
A vapor barrier film must be used when installing thermal insulation indoors - in this case, it is installed on the warm side of mineral wool. This allows you to protect the insulation from water vapor from the premises. Reinforced polyethylene can be used as a vapor barrier, which is placed between the insulation and the cladding.
If the design allows, between the insulation and exterior finish a ventilated air gap must be provided. This will help keep the mineral wool dry, without compromising the vapor permeability of the building.
What if you need to use wool in a layer of 15 or 20 cm, and the insulation is supplied with a thickness of 5 or 10 cm?
There is nothing complicated here. Need to calculate required thickness using formulas or using an online calculator (we talked about this in a previous article), and then you can easily build a warming barrier from several layers. In addition, this method makes it easy to eliminate the problem of cold bridging and joint blowing. To do this, when installing the insulation, the sheets of the outer and inner layers should be shifted relative to each other by 20-30 mm in order to reliably close the seams.
Is it necessary to use protective equipment? Which?
Mineral wool is considered a safe heat-insulating material, both during operation and during installation. However, when working with this insulation for a long time, it is still better to protect yourself using personal protective equipment.
Stone wool, compared to glass wool, is much more convenient to use and safer, but care should still be taken when installing it. It is best to work on non-hot days in overalls made of dense fabric, covering the entire body from contact with mineral wool. touch this stuff with bare hands not recommended, to protect them, you can use "glazier's gloves" - fabric with rubber or silicone coating in the area of the palms. It is also imperative to protect the eyes and scalp. Wear a respirator to protect your respiratory system.
During the installation of stone wool, a break should be arranged to ventilate the room. Open packs of material must be carefully shifted, preventing them from falling, so that microparticles do not stand out from them. At the construction site during the installation of thermal insulation there should be no children, as well as people who do not use protective equipment.
Are there any nuances in transportation and storage?
Mineral wool insulation should be stored in whole packages on a flat dry surface, the height of the stacks should not exceed 2 meters. Stacks are made in enclosed spaces protected from rain and moisture. If mineral wool is stored outside, it must be covered with plastic wrap or tarpaulin.
Mats and insulation boards are transported in a horizontal position in covered trucks. During transportation, the insulation must be protected from mechanical damage and atmospheric precipitation. During loading / unloading and transportation, do not compress the material too much.
You need to unpack the mineral wool correctly. To do this, the insulation is taken out of the package immediately before installation, which significantly reduces the risk of damage to the thermal insulation. Insulation packaging can be used on a construction site when laying out mineral wool (when you need to protect it from pollution), it is also suitable as bags for construction debris.
Which cotton wool is better?
There is no single answer to this question, since different conditions the best option would be a material of a different type.
Basalt soft wool. Use it where high loads are not expected. This material can be used to insulate walls made according to frame technology, as well as for thermal insulation of floors and roofs. The fact that cotton wool is soft does not mean at all that it performance characteristics bad. It is simply made from thin fibers, which ensures the presence of many cavities in the insulation, in which air is trapped, which prevents heat loss.
Mineral wool of medium hardness (density). It is used mainly for the insulation of ventilated facades, where high-velocity air flows are created in the air cavities. It is also used for fire prevention measures, sound and heat insulation of ventilation ducts. Mineral wool of medium density can be installed without problems instead of soft basalt wool, but the cost of thermal insulation will be more expensive.
Rigid basalt wool. This insulation is used in places where high loads on it are possible. For example, where it is planned to insulate walls with reinforcement and plastering (wet method) or when creating certain types of floors.
Cylindrical heaters for pipes. Usually they are produced with a diameter of more than 50 mm. They are slotted parts that can be deployed and put on the pipe, or two-piece models that are connected on the pipe.
Foil basalt wool. This thermal insulation material is characterized not only by low heat transfer, but also reflects heat, directing it inside the premises. Mineral wool can be covered with foil on one or both sides. When laying, the heat insulator is installed with the foil side to the heat source. The scope of this insulation is quite extensive, it is considered a universal material suitable for all methods and types of thermal insulation.
Stitching cotton. It is a very durable mat, one side of which is sheathed / reinforced with steel mesh (galvanized, stainless, fire-resistant, acid-resistant). Cloths can be of various thicknesses, can be used to perform various kinds thermal insulation. Stitched wool is usually non-combustible, so it can be used to insulate surfaces with elevated temperatures(up to plus 660-700 degrees).
important technical specification mineral wool is its specific gravity. Insulation with a density of up to 75 kg per cubic meter is ideal for thermal insulation of planes where heavy loads are not expected, for example, for laying in ceilings in attics and roofs. Basalt wool of low density is often used for wrapping pipes of heating plants, boilers and similar units / communications.
Stone wool, the density of which is up to 125 kg per cubic meter, holds its shape well and is great for insulating ceilings, walls inside buildings, various vertical structures. It is used for thermal insulation brick walls, as well as surfaces made of foam block or aerated concrete. Mineral wool of this specific density allows not only to insulate the building, but also to ensure its reliable sound insulation.
Basalt wool of high density - from 175 to 200 kg per cubic meter is characterized, in addition, by increased rigidity, hence the abbreviation in its name (PPZh). Such a heater is used for thermal insulation of initially too cold planes - reinforced concrete, sheet metal. The PZH-200 brand is also excellent for arranging additional protection of residential buildings from fire. Only high-density mineral wool can be installed using wet facade insulation technology.
Through the roof of the house, the greatest heat loss of houses and buildings occurs. This is not noticeable to the lower floors of buildings, but more heat is needed to heat the upper floors.
To insulate the roof, you need to choose best option material. It must be not only airtight, but also fire resistant and non-toxic.
Taking into account such requirements, mineral wool will be the best option.
There are varieties of mineral wool: glass and basalt. The latter is produced from a rock - gabbro-basalt. During manufacture, carbonates are added to it, which allows you to regulate its acidity.
Basalt wool
Such a factor as acidity is of great importance for mineral wool. The more acidic vata is, the less sensitive it is to water.
The type of cotton wool, in which the acidity is greater, is considered more durable. Synthetic, bituminous or composite clays are added to give shape. Glass wool does not require special explanation, its name speaks for itself.
it mineral composition, for the manufacture of which the same components are used as for glass (it can be broken glass).
The two types of wat differ in their properties. Glass wool is usually 15 microns thicker (from 3 microns), but basalt wool is several times longer.
The conclusion suggests itself: glass wool is more durable material, able to withstand more aggressive environmental factors than basalt. Also, glass wool does not burn.
Roof insulation with mineral wool is difficult when working on roof slopes with a truss structure. In such cases, it is better to use dense cotton wool. To prevent moisture from accumulating under the roof, you need to use cellulose wool.
Advantages and features of mineral wool
Mineral wool has the following advantages:
- a wide range of products. Mineral wool is produced in the form of plates, rolls or mats. Due to this, it is possible to choose the option that is best suited for thermal insulation of a certain section of the building. Also, the types of mineral wool differ in density: the material in the form of plates has a high density, and the roll insulation is lighter;
- has high thermal insulation characteristics. mineral wool has porous structure. This material consists of small layers. Due to this, it retains heat well, and also provides excellent sound insulation;
- fire safety of the material. Mineral wool does not burn and does not spread fire. For this reason, it is often used for thermal insulation of interfloor floors. Mineral wool manufacturers claim that this material can withstand temperatures in excess of 900 degrees Celsius;
- mineral wool is not deformed and this is a very important advantage. This material does not shrink, therefore, there is no formation of "cold bridges" that cause heat loss;
- frost resistance. This property allows the use of mineral wool for thermal insulation. external elements the buildings;
- mineral wool is an environmentally friendly material. It is used for thermal insulation of sanatorium and medical institutions, as well as children's rooms.
This heater is produced in various forms- plates, cylinders, mats; you can buy cotton wool covered with foil.
Mineral wool has features that cannot be called positive. These include:
- low strength. This is due to the high porosity of mineral wool;
- to ensure a high level of thermal insulation, this material should be used together with a waterproofing film and a vapor barrier membrane;
- when using mineral wool with fiberglass, it becomes unsafe because formaldehydes are added to it;
- high hygroscopicity (therefore, high waterproofing is done).
To attach such a heater to inside planks are nailed to the rafters (a lattice is made of them), to which cotton wool will be attached. From the outside, cotton wool is laid in one layer (the layers depend on the thickness of the cotton wool).
After laying the insulation, waterproofing is applied. The important thing in this step is not to confuse the sides of the insulation. The top layer does not allow moisture to pass through, and the bottom layer is an obstacle to steam.
The waterproofing is not stretched; between it and the cotton wool remains air space. There should be air space in front of the skate, which will create additional traction.
Warming method
To start insulating the roof with mineral wool, you need to cut (if necessary) it so that it fits in size to the distance between the rafters.
If cotton wool is used, for example 10 cm, and the thickness of the thermal insulation is more than 10 cm, then another layer of wool is laid already perpendicular to the rafters. There are two ways to strengthen the roof of non-residential premises.
The first is to insulate the ceiling, and the second to strengthen the roof slopes. The first case does not require any special preparation or special costs.
No need to bypass the rafters, as in the second case. Strengthen roof slopes non-residential premises, thus, is cumbersome. Would need a large number of cotton wool, which must be strengthened by bypassing the rafters.
Mineral wool grades
Mineral wool is produced in the form of mats and slabs. It is used for thermal insulation of the ceiling, partitions, roofs, partitions, as well as internal walls. When working with this material, as a rule, there are no special problems. Mineral wool can be laid not only on a flat, but also on a non-standard surface.
Mineral wool brand p-75
There are the following brands of mineral wool, which differ from each other in their density:
- P-75. The mineral wool of this brand has a density of 75 kg / m3. It is usually used for thermal insulation horizontal surfaces, which are not subjected to serious loads (some types of roofs, attic spaces). Also, cotton wool of this brand is used for warming oil and gas pipes, as well as pipes of heating plants. Mineral wool of lower density is also produced, but it is used in cases where there is almost no load.
- P-125. This material has a density of 125 kg/m3. It is used for thermal insulation of partitions, ceilings, floors and interior walls of the room. The mineral wool of this brand creates good sound insulation. Therefore, when using it, you can not only insulate the building, but also create good sound insulation.
- PZh-175. This is a dense material with increased rigidity. It is used for insulation of ceilings and walls made of profiled metal or reinforced concrete.
- PPZH-200. Mineral wool of this brand has increased rigidity. It is used in the same cases as PZh-175. The difference between PZH-200 and the previous brand is that it is fireproof.
How to cut mineral wool?
It is advisable to cut stone wool insulation with a special knife with a serrated blade or a hacksaw. The tool used for this purpose must be well sharpened.
This is necessary so that the torn out fibers of the insulation are as small as possible. Many manufacturers of thermal insulation materials offer customers special cutting tools. These are knives, the length of which is approximately 300 millimeters, as well as saws with straight teeth.
If there are no special tools, then you can use a kitchen bread knife with a wavy edge and fine teeth. For cutting mats with a thickness of 50 millimeters and soft plates, you can use a conventional mounting knife.
It is important to note that the heat-insulating material must cover the insulated space very tightly. Therefore, it is necessary to leave allowances before cutting.
Thermal insulation of the floor
Interfloor and attic floors are made of load-bearing beams or reinforced concrete. In the first case, the heat insulator is placed in the space between the floor beams, and in the second case, on the surface of the slabs.
Attic floor insulation
First of all, you need to install a vapor barrier. It will protect the thermal insulation from moisture and steam. Before laying the vapor barrier film, it is necessary to study the instructions for its use. If the vapor barrier is laid incorrectly, then it will not fulfill its tasks.
Flat roofs are usually insulated with rigid mineral wool boards with a density of more than 150 kg/m3. A layer of waterproofing is laid on top of it. It is necessary to lay the plates very tightly to each other. In this case, the seams should not be located on the same line. Optimal Thickness layer of mineral wool is 25 centimeters.
You can also insulate interfloor and attic floors with sawdust. They are used together with sand, clay, lime and cement. The composition provides good thermal insulation.
Expanded clay is also often used to insulate the attic. This material contains a large number of pores, due to which the function of thermal insulation is provided.
When using these materials, financial costs will be less, and the quality of thermal insulation is no worse than in the case of mineral wool insulation. When choosing a heater, one should take into account the height and area of \u200b\u200bthe building, the materials from which it is built and other parameters.
Video about the thermal insulation of the attic floor:
Pitched roof insulation
To insulate the roof with mineral wool, it is necessary to install steam, hydro and thermal insulation. The pitched part of such a roof is a multilayer cake. It is mounted both inside and outside the roof.
To create high-quality thermal insulation of the roof, you must perform the following steps:
- perform the installation of a vapor barrier layer. It will protect the thermal insulation from air saturated with moisture;
- as thermal insulation material use mineral wool;
- to protect the rafter system and insulation from precipitation, a waterproofing layer should be installed;
- it is necessary to provide ventilation gap. It is created by mounting a counter-lattice;
- on the last step roofing material is laid.
Laying a waterproofing membrane
- When insulating the roof of a building with mineral wool, it is necessary to ensure that it does not block the ventilation hole.
- If during installation work If a superdiffusion membrane is used, then the heat insulator should be laid tightly on it. This is necessary so as not to block the ventilation gap.
- If a conventional roofing film is used, then two gaps must be made: top and bottom.
- When laying mineral wool boards in rows, make sure that the joints do not coincide with each other.
- In order for the insulation to fit snugly against the surfaces of the rafter legs, it is necessary to choose mineral wool of such a size that its width is slightly greater than the distance between the rafters.
- Mineral wool slabs should fit very tightly to each other.
- When insulating the roof with mineral wool, it is necessary to install a waterproofing layer. In this case, it is necessary to monitor the quality of the connection of the waterproofing film.
Mounting errors
Before installing mineral wool, you must perform the following steps:
- check the truss structure. If rotten elements are present, they must be replaced;
- treat the roof with antiseptics;
- check communication systems: water supply and electricity;
- pitched roofs are best insulated with material in the form of slabs or rolls, since they fit well on the crate.
Between a layer of mineral wool and roofing material ventilation space must be present. When warming pitched roof in a private house, not only thermal insulation is provided, but also sound insulation.
Inexperienced professionals often make the following mistakes:
- do not use a heat insulator whose width is less than the distance between the rafter legs. In this case, heat loss will occur through the cracks;
- do not insulate the roof with material with high level humidity. It will cause rot wooden elements roof frame;
- if you do not install hydro and vapor barrier, then the thermal insulation system will not work properly, moreover, its service life will be significantly reduced.
Video on how to insulate the roof from the inside with your own hands:
Mineral insulation has a fibrous structure, violation of which leads to a decrease thermal insulation properties . This makes it inefficient to use scissors for thick fabrics or cardboard, as well as cutlery or stationery knives. Therefore, the answer to the question of how to cut mineral wool correctly without violating its structure will be useful for beginner builders.
On an industrial scale, special machine tools are used to cut mineral insulation. Consider how to cut mineral wool insulation yourself at home.
Often, a mounting knife is used to cut mineral wool. But it has one drawback - a short blade, which is not suitable for working with thick insulation boards. In addition, the blade becomes dull quickly and needs to be replaced.
Sometimes a special hacksaw is used for wood or metal, and craftsmen have found how to cut mineral wool at home - a serrated kitchen knife for cutting bread.
But still, when choosing how to cut stone, glass or slag wool, it is better to use special tools.
Knife with stainless steel blade
Knife for cutting insulation with a long blade made of durable stainless steel suitable for working with mineral wool of any thickness. To cut the insulation of different hardness, there are larger and smaller teeth on each side. Such a blade easily enters the thickness of the plate, allowing you to make even curly cuts thanks to the sharp tip.
Knife with carbon steel blade
Mineral wool cutting knife with carbon steel blade It has high quality cutting and easy to sharpen. However, it requires more care than a stainless steel blade, as prone to rust. It must be wiped dry after each use and lubricated.
Example: MORA knife for cutting mineral wool
The Swedish company MORA produces tools for cutting mineral insulation. Knife with a blade stainless steel is used for cutting stone wool and glass mineral wool. The blade is made of special cold-rolled stainless steel and has a serrated edge. Ergonomic and comfortable plastic handle suitable for use with gloves. Its characteristics:
- total length - 500 mm;
- blade length - 335 mm;
- blade thickness - 1 mm;
- weight - 0.238 kg.
Knife with a blade carbon steel is used for cutting various types of mineral insulation. It has a smooth, high-quality carbon steel blade with a length of 350 mm. plastic handle provides a good grip when wearing work gloves.
How to cut mineral wool
Mineral wool in structure - fibers, and, accordingly, when it is opened, small particles of these fibers enter the air. To prevent them from getting into the respiratory tract and on the skin, it is important to create safe working conditions:
- ensure good ventilation in the work area;
- use overalls and protective equipment - overalls, gloves, a mask or respirator, goggles;
- Wash thoroughly immediately after finishing work. cold water hands and then face.
To minimize the amount of harmful dust in the air, cutting mineral wool should be done with tools with a well-sharpened, sharp working edge. Better to cut across the grain.
To obtain strips of the same width mineral insulation, produced in rolls, it is recommended to first cut directly in a roll, without unfolding, and mineral wool boards are cut one at a time.
To ensure even and accurate cuts, you must first mark the material or cut directly along the ruler.
What to do with scraps and mineral wool residues
If trimmings remain after working with mineral wool, you can use them for insulation, for example, a garage or a barn. Some choose this a budget option insulation, so that you can sell the leftovers at a low price.
There is also the option of recycling waste for recycling purposes. In this case, the remains of mineral wool boards are crushed using special equipment.
Mineral wool cutting video
On the video - cutting mineral wool with a special tool.