Insulation of the floor in the attic of a brick house. The procedure for insulating the attic with mineral wool. Choosing the right materials and insulation

When insulating a private house, one must not forget that special attention should be paid to such a place as the attic.

Warm air tends to rise to the top, and therefore, in a temporarily unheated room, heat can escape through the space of the cold attic. Therefore, the issue of warming the attic must be solved without delay.

1 Why do you need insulation of the attic floor?

Insulation of the cold floor of the attic with stone or mineral wool, by and large, is needed in little-used rooms that are properly equipped with special roof ventilation.

The attic, or rather its overlaps, perform the function of a kind of border between heat and cold. In such places, the attic floors are exposed to intense moisture due to the formation of condensation.

However, it is possible to properly insulate the floors in the attic of the house with mineral wool with your own hands. The very process of insulating the floor in the attic with mineral wool is the creation of a durable heat-insulating coating, which will have a low degree of thermal conductivity.

The very technology of insulation with mineral wool flooring in the attic, as well as implies strict adherence to its stages and requirements.

By itself, this technology is quite simple and straightforward. Good thermal insulation of the attic floor with mineral wool helps to close unwanted gaps.

To do this, the insulation must be laid tightly. In most cases, mineral wool is used to insulate the attic of the house.

The presented insulation is the most suitable for this type of work; it can also insulate the floor surface in the living quarters of the house.

With the organization of good insulation with mineral wool, the most optimal temperature will be maintained in the living quarters.

If the procedure is not performed correctly, moisture rising from the floor of the house will lead to the formation of condensation.

It will accumulate on the ceiling and then seep through the ceilings. The resulting temperature difference in those areas where the attic ceilings are adjacent to the walls of the house, initiates the formation of mold and microscopic fungi, which can be causative agents of allergic diseases.

1.1 Requirements for insulation of the attic

The process of insulating the attic floor and, more precisely, the level of its quality has a direct impact not only on the size of heat loss, but also on the duration of the operational life of the entire rafter structure and roof covering.

The fact is that the water vapor inside the heated room diffuses to the attic of the house. In order for the insulation used to provide a high degree of calculated efficiency of the heat-insulating layer, it must always be dry.

Based on this, the insulation must be protected from excessive humidification by the vapor of the rising heated air using a special vapor-proof material.

If the attic space is well insulated, then it will provide not only high-quality thermal insulation, but also contribute to an increase in the operational life of the entire roofing structure.

If there is no vapor barrier, steam will penetrate through the unprotected attic floors and condense on the ceiling surfaces.

This will lead to the fact that moisture will drain onto the rafters, which, under its influence, will slowly begin to rot from the inside.

As a result, the likelihood of destruction of the entire roofing cake increases. The thermal insulation performance of the structure also decreases due to the fact that the tightness of the vapor barrier layer has been broken.

Before insulating the attic, you need to drain the layer and remove moisture from the entire attic space. For this, ventilation should be carried out through the windows. They may be:

Skate like;
Cornice;
Slotted;
Auditory.

In order to ensure the maximum ventilation intensity, the indicator of the total area of all ventilation openings should be equal to 0.2-0.5% of the attic floors.

If all the work is carried out correctly, then icicles will not form on the roof in winter. The very process of warming the attic space is carried out not from the side of the living quarters, but from the floor of the attic.

So it is most convenient to lay insulation, the choice of which depends on the technology used and the design features of the structure.

1.2 Features of insulation of beamed ceilings

When implementing such a thermal insulation scheme using mineral wool, heat is stored in the space between the beams. Their usual height is almost always sufficient for this, however, if necessary, several bars are stuffed on top.

The lower part of the overlap is sewn up using molded material as with. For this, lining or drywall sheets can be used.

On top of the beams, the sub-floor covering is laid. This can be a grooved board, plywood sheet or OSB board. Mineral wool is adjusted to a previously prepared special vapor barrier layer.

An alternative to it can serve as an ordinary film made with polyethylene. If the vapor barrier material is foiled, then it is laid with a shiny surface down.

The intermediate distance between the beams is filled with mineral wool with the required thickness parameters. The surface of the beams must be equipped with an additional insulation layer.

This will lead to blocking of the so-called cold bridges and significantly reduce the overall level of heat loss. If a high quality timber was used to create the beams, then the finishing material should creep directly onto their surface.

Minvata is placed between them as if, and the attic floor is laid on top. The use of this technology is especially important in houses that are made of logs or beams.

It is important to protect the mineral wool from the smallest drops of moisture with a high degree of reliability, this is especially true if the roof has minor coating defects, due to which leaks occur.

The layer of mineral wool must be reliably protected from the effects of wind from the side of the cornice. For this, mineral wool slabs with a high degree of density are used.

2 Why is mineral wool used to insulate the attic?

In most cases, when insulating attic floors, the consumer's choice falls on mineral wool. Its advantage lies in the fact that no special skills are required for its installation.

Mineral wool has excellent thermal insulation properties. Its structure consists of thin glassy fibers, the length of which ranges from 2 to 60 millimeters.

High sound insulation characteristics are provided due to the presence of a large number of air pores.

These pores are located in the space between the fibers and can occupy 95% of the total volume of the insulation. Minvata is presented in three varieties, it can be glass and stone basalt.

Basalt wool is made using molten basalt rocks, into which binding elements are added.

It can be a carbonate type rock, which regulates the acidity level of the substance, which entails an increase in the operational life of the insulation. Glass wool exhibits high heat-resistant properties and is able to withstand temperatures up to +450 degrees Celsius.

2.1 Technology of insulation of attic floors with mineral wool

When carrying out work related to mineral wool, it is important to comply with all safety requirements and regulations.

This is due to the fact that in the process of cutting and laying such material, the air is filled with the smallest particles that can enter the respiratory organs and thus harm human health.

When carrying out installation, be sure to take care of the availability of personal protective equipment. Goggles, a respirator and heavy rubber gloves should be available.

The very process of warming attic floors begins with the selection of the necessary tools and additional materials. You can't do without:

Insulation

Planks and plywood;
Vapor barrier film;
Minwaty (excellent);
Waterproofing;
Scotch tape;
Roulette;
Knife;
Construction stapler;
Spatula.

The essence of the insulation technology lies in the fact that the insulation must be carefully laid in the space between the attic floors or beams.

To enhance the thermal insulation qualities, a reliable vapor barrier should be used. Warm and moisture-saturated air will continuously rise from the living rooms and go up through the ceiling.

There, in the under-roof space, he will collide with a layer of insulation. In view of the fact that mineral wool is generally recognized as a vapor-proof material, it will take all the outgoing moisture inside itself.

If it is left without the necessary access to air and sunlight, it will gradually shrink and, in the end, will lose all its heat-insulating qualities.

In order to avoid such destructive consequences, it is necessary to lay a vapor barrier material under a layer of mineral wool.

Before starting the main work, it will be necessary to carefully calculate the required amount of insulation.

The amount of wool purchased depends on how many layers you plan to use when covering the attic. In addition, the parameter of the thickness of thermal insulation directly depends on the characteristics of the climatic conditions in the region.

2.2 Correct insulation of the attic floor (video)

August 27, 2016
Specialization: Capital construction works (laying of foundations, erection of walls, construction of a roof, etc.). Internal construction work (laying of internal communications, rough and final finishing). Hobbies: mobile communications, high technologies, computer technology, programming.

If you live in an apartment building, then you hardly ever thought about insulating an attic. Moreover, you hardly knew about the presence of such a technical room in the building, unless, of course, you ran to the roof as a child.

However, in a country house or a country cottage (which I am currently building for my son), the roof space plays a huge role. An open expansion tank of the heating system, ventilation pipes, and chimneys are often installed there. And sometimes they equip living quarters - attics.

Therefore, I will not talk for a long time how important thermal insulation measures are for this room, but I will just tell you how to insulate the attic of a private house using the example of a country house of my own son.

I think that the described technology will be useful to everyone who builds with their own hands or is going to build a dwelling outside the city.

Materials for thermal insulation

The attics have been insulated for as long as I can remember. My great-grandfather and grandfather used for this purpose hay and straw, sawdust and shavings, and some in their village - and dry leaves from trees.

Dad was already a more "advanced" builder and was cold - in a private house and in the country, he insulated the attic with expanded clay and old soldiers' blankets. By the way, expanded clay granules are also used in modern construction.

Now I will not tell you which is the best option from the above, since I can offer more technologically advanced and effective thermal insulation materials for insulating the attic.

However, before that, I will note what technical characteristics should be inherent in a heat insulator so that it can be used for the described work:

Low weight. After installation, the material should not exert a large load on the attic floor, roof rafters and load-bearing walls.

Otherwise, even during construction, more durable building materials will have to be included in the project, which increases the amount of the final estimate.

Security. The material used for insulation should not harm human health.

Therefore, both the floor of the cold attic and the roof must be insulated with heat insulators that do not emit hazardous chemical compounds into the air. Especially if you plan to equip a living room there in the future.

Easy to install. The less effort you need to spend on installing heat insulators, the better, isn't it?

In addition, there is not a lot of space in the under-roof space of some houses, so it is not very convenient to work there. I always try to buy materials that do not require complex equipment to be installed.

Low coefficient of thermal conductivity. The better this indicator is, the smaller the layer of thermal insulation material needs to be used. Accordingly, the interior space of the attic will not be greatly reduced.

Again, I think this is important, since I plan to make an attic in my son's dacha in the attic. But you, I think, are not very interested in laying thermal insulation with a thickness of 20-30 cm.

Hydrophobic properties. In attics, the air is often humid, which reduces the efficiency of the thermal insulation layer.

I advise you to choose materials that are either treated with water-repellent compounds, or those that do not change their technical characteristics as a result of wetting.

Fire safety. The roof is where there is a risk of fire due to improper installation or blockage of the chimney.

Therefore, when choosing a material, I would give preference to those varieties that do not ignite under the influence of open fire and do not support combustion.

Of course, I failed to choose the perfect insulation that 100% meets all of the listed requirements. But still I'll tell you about those of them with which I had to work.

So, I insulated the attics:

polyurethane foam;
foam;
mineral wool;
expanded clay.

I'll tell you about them in more detail.

Polyurethane foam

The raw material for the manufacture of this heat insulator is plastic. Insulating an attic with polyurethane foam is a pleasure, but this requires special equipment. The fact is that the insulator is applied by spraying, for which compressors are used.

But there is no need to buy screws, glue mixtures, lathing, and so on. And the polyurethane foam itself is applied very tightly, leaving no gaps through which cold air can penetrate into the under-roof space.

After hardening, the insulation becomes tough, therefore it additionally strengthens the structure. The material has antiseptic properties, mold, fungus and other microorganisms do not multiply on its surface.

If you need to insulate the ventilation pipe in the attic, then you can also use polyurethane foam. Only not sprayed, but in the form of ready-made shells with a protective layer of aluminum foil. They just need to be secured to the pipelines with adhesive tape or plastic ties.

The biggest drawback of the material in question is the high price. However, if we consider the total cost of the work, then it is possible to save money, because additional hydro and vapor barrier is not required in this case.

Styrofoam

This insulation, like polystyrene foam similar to it in technical characteristics, is widely used for insulating premises under the roof. I personally prefer the expanded polystyrene obtained by the extrusion method. It is more durable, does not burn, has a low coefficient of thermal conductivity and is not damaged by rodents.

The cost of insulation is quite affordable, and anyone, even the most inexperienced summer resident, can lay it in the attic. Polystyrene is processed with hand-made construction tools and fixed with dowels.

Mineral wool

Fiber heat insulators are a versatile material. Mineral fiber heaters are rolled, slab, in the form of a dry mix, and so on. They are great for insulating attic floors and roofs.

Basalt fiber, from which mineral wool is made, has a very high melting point. Therefore, this insulation can be used for installation on chimneys, the surface of which can be very hot.

There is one point here. The insulation is not waterproof and can lose its heat-shielding properties when moistened. To avoid this, when insulating, it is necessary to install waterproof and vapor barrier membranes. Or buy those varieties of mineral wool that are treated with special water-repellent compounds.

The bottleneck of some types of mineral insulation is environmental friendliness. In the manufacture of basalt mats, a certain amount of formaldehyde resins is used, which can be harmful to human health. Especially during the installation process.

Expanded clay

Granules of this material, as I already told you, were also used by my father when insulating his first summer cottage. Expanded clay has a low coefficient of thermal conductivity and weighs a little. However, it is free-flowing, therefore it can only be used to insulate the floor of the under-roof space.

But the installation process itself does not require any tweaks. It just needs to be poured onto the floor, and then thoroughly protected from moisture with a moisture-proof membrane. If you are going to later equip the attic, you can cover it with a screed on top, and then lay a decorative covering.

Self-insulation of the attic space

It seems that they have decided on the most popular thermal insulation materials, now I will tell you how to properly insulate the under-roof space so that there you can equip an attic in the future.

Let's take up the question of how to lay insulation under the crate, because this method will allow you to fill the decorative material of your choice on top without any problems in the future.

In my son's attic, I decided to use mineral wool, but I'll tell you about foam plastic right away, since the work technologies are similar, and foam plastic is easier to work with if you are a novice builder.

The whole process of warming consists of several stages:

preparation;
waterproofing;
laying a heat insulator;
vapor barrier;
arrangement of lathing and installation of decorative sheathing;
insulation of engineering communications;
thermal insulation of the floor.

I'll tell you about each stage in more detail.

Preparatory activities

Let's start, as usual, with preparation, because it is unlikely that your attic is already ready for construction work.

After all, this room is used in almost 100% of cases as a rubbish storage, where all unnecessary things are demolished (and sometimes they are taken from the apartment). In the attic of my son's dacha it was clean, since the house is new, but in my home, when sorting through the rubble, I found old books, clothes, several family heirlooms (which my wife did not consider as such) and much more.

In addition, if you have tried to carry out insulation before, then I advise you to get rid of any traces of this process. For example, remove sawdust, felt scraps, construction debris, and so on from all cracks. Believe me, I have insulated attics more than once and I know how important this is.

By the way. And drive all the spiders out of the attic, and then clear the room from the cobwebs. After all, you will build an attic for yourself or your children, and not for any insects.

Last moment. Bring the necessary tools into the attic and provide lighting. It is unlikely that you have sockets there, so you have to stretch out an extension cord with a light bulb. Although these measures seem obvious to you, since I had to return to the city for an electric one, since not a single extension cord at the construction site reached from the switchboard to the attic.

Waterproofing

A waterproofing membrane is needed in order to protect the insulation layer itself and the room under the roof from excess moisture. This is especially important if the roof was laid for a long time (for example, you are insulating the attic of an old house) and the roofing materials were not used the most modern.

The moisture-proof film is installed directly on the rafter structure. It must be stretched and overlapped so that after the end of the work an airtight layer forms. You can fasten the material with a construction stapler with staples.

Insulation laying

The thermal insulation material, as I said, must be mounted on a pre-assembled lathing. However, if you want to save a little, you do not need to design a separate frame. Its role will be perfectly played by the roof truss system.

In the latter case, in order to press the material and be able to mount the decorative cladding, it will only be necessary to equip a light counter-lattice at a certain distance from the surface of the heat insulator. Then you get a small ventilation gap that removes excess moisture from the insulating layer.

So, the scheme of work on laying the insulation is as follows:

The rock wool rolls must be cut so that their width matches the distance between the rafter supports. Then lay it under the roof surface, gluing it to the surface or temporarily attaching it with wooden slats.

To make installation easier, you can use mineral mats... Their width should slightly exceed the distance between the rafters, so that after installation they snap into place and do not fall out.

Polyfoam must be cut as accurately as possible so that it comes close to the installation site... The gaps between the insulation panels will greatly reduce the effectiveness of the insulation measures, therefore they need to be blown out with polyurethane foam.

Vapor barrier

After installing the insulation, you need to install a vapor barrier membrane. It will protect the insulating material from the penetration of moisture formed in the process of human activity.

For vapor barrier, special films are used that do not allow the heat insulator to wet, but do not prevent air infiltration through the enclosing structures. As a result, a comfortable microclimate for living will be formed in the attic, if you look at it from the point of view of humidity.

So, after installing the insulation, it is necessary to attach a vapor barrier to the rafter supports (which act as a lathing). This must be done with a stapler, carefully pulling the film.

The edges of the material overlap each other to prevent the mineral wool from getting wet. To further insure yourself against surprises, I recommend gluing the seams with adhesive tape.

Vapor barrier films allow air to pass through only in one direction. Therefore, be sure to unfold the membrane to the correct surface before installing.

Counter grill

Having finished with the films, you can proceed to the completion of wall finishing operations (well, or the roof, it depends on how you look at it). I will use it for this, but in the same way you can fix OSB plates, drywall, lining, and so on.

Here, too, there is an opportunity to significantly save on the purchase of materials and reduce the time for carrying out all the work. The fact is that the main details of the lathing will be powerful rafter legs, and you will only have to make crossbars, which will serve as additional stiffeners for the sheathing.

The material for the transverse frame can be a wooden lath or a galvanized profile. The essence of this will not change. The details just need to be screwed from above to the rafters so that they are located at right angles to them. The step between adjacent elements depends on the decorative finish, I made 30 cm so that the sheathing does not sag under load.

The decorative finish itself also depends only on your imagination. I'm going to glue the wallpaper on top for now to save money, and then I'll come up with something more beautiful. You can do the same.

Just before gluing the wallpaper, do not forget to putty the seams between the plywood sheets and perform other necessary operations (priming and so on).

Insulation of engineering communications

If you do not provide for the creation of an attic, it is imperative to insulate the ventilation ducts in a cold attic, as well as, if available, heating, water supply and smoke exhaust pipes (which term you came up with).

Of course, you can use mineral wool for this, wrapping it around the pipes, wrapping it with roofing material and securing it with wire. But why complicate your life if you can buy ready-made shells for pipes of the required diameter (made of foamed polyethylene, polyurethane foam, polystyrene, and so on). They just need to be snapped onto the pipe and fastened with tape for fidelity.

The cost of these insulators is low, so you definitely won't go broke.

Insulation of the attic floor

The floor is a horizontal surface, so it can be easily insulated with bulk material. For example, expanded clay. But since I started working with mineral wool (foam), I will not buy expanded clay, I will limit myself to what I have at my disposal.

So, the technology for insulating the attic is as follows:

First you need to clean the surface of dust, accumulated debris, foreign objects, and so on.
Then install the support beams. I make them from wooden blocks with a section of 20 by 10 cm. You can select the height of the logs based on the thickness of the thermal insulation material you have.

The entire surface is covered with a layer of waterproofing agent. Be sure to check the tightness so that the mineral wool does not get wet, as this may affect its technical characteristics.

Cotton wool is laid on the waterproofing layer. Choose a material that is specifically designed to insulate horizontal surfaces. For example, Isover KT37.

The vapor barrier membrane is again pulled from above, onto which the facing material is stuffed. I used plywood, which I plan to cover with linoleum.

If you do not plan to operate the attic as a living space, then you can not insulate the roof, but only the floor can be insulated. In this case, you need to pay attention to some features:

Wood for logs and sheathing must be treated with hydrophobic, fire-fighting and antiseptic compounds in order to maximize its service life.
For the entrance, it is better to use an insulated hatch to the attic, since it is this structural element that is often the source of large heat losses.

Now we can say with confidence that the insulation of the floor (or the ceiling from the side of the cold attic) has been completed in full. And in order to maximize the effectiveness of thermal insulation measures, I still advise you to make an insulated hatch with a ladder, as described in the video in this article.

Output

As you can see, there is nothing terrible or difficult here. If you liked the material or have any questions, you can ask them in the comments. I would also be grateful for stories about how you carry out the insulation of an attic in a private house with your own hands.

August 27, 2016

If you want to express gratitude, add clarification or objection, ask the author something - add a comment or say thank you!

For the comfortable operation of the building, it is necessary that the ceiling of the attic be well insulated to prevent the temperature of the ceiling surface from dropping below the dew point. Otherwise, spots of moisture will appear on the ceiling and walls, which will only worsen the appearance of the room, but also cause the growth of mold and the development of fungi, which is problematic to get rid of. Therefore, increased requirements are imposed on the thermal protection of the attic floor.

In accordance with the standards, the heat transfer resistance for the attic floor must be at least the following value: Ro = 4.15 m 2 ° C / W. The attic floor of a country house is insulated with slabs of mineral (basalt) or glass wool. Insulation boards should be placed in the spaces between ceiling beams or on floor slabs. Mineral wool is laid on a vapor barrier layer or on a plastic wrap.

The foil-lined thermal insulation material is laid with the shiny side down. The space between the beams is filled with a layer of heat-insulating material. To reduce heat loss through the cold bridges, another layer of thermal insulation is placed on top of the beams.

To reduce heat loss from lightweight fiber insulation under the influence of drafts, it is protected with a vapor-permeable windproof material. The use of such a material allows you to increase the thermal protection of the attic floor and protect the insulation from getting wet if moisture drops on it (in case of damage to the roof or leaks).

The layer of insulation from the eaves must also be protected from the wind by plates of high density mineral wool or boards, which are installed on the edge.

The attic or attic spaces, divided by partitions into compartments, can be insulated in different ways.

The first method: if the attic is non-residential, then only the floors should be insulated - the ceiling of the building.
The second method: if the attic has an attic, then you need to insulate, in addition to the floors, and the roof.

To insulate the roof of the attic and premises, the following are usually used:

Construction felt.
Mineral wool in various designs.
Styrofoam.
Polyurethane foam.
Basalt, glass wool, ecowool.

Attic floors can be insulated with the following materials:

Construction felt, mineral wool, glass wool.
Foam silicate boards.
Expanded clay, slag, ash, sawdust, straw, reeds.

Before insulating the attic, the joints of the floor and the roof are checked, the cracks are sealed with tow soaked in a lime solution. You can also use polyurethane foam, silicone adhesives and sealants.

Before carrying out work, all wooden structures are covered with antiseptic and fire retardants.

When insulating a roof made of asbestos-cement sheets, special attention should be paid to the gaps that are formed by waves of asbestos-cement sheets. If there are gaps, then they are filled with tow in a lime solution.

The presence of protective covers, collars and aprons is checked in the places where asbestos-cement sheets adjoin parapets, pipes and walls. The elements of the coating should be allowed to enter the protective floors at least 15 cm.

Insulation of the attic with various materials

To insulate the attic and the attic in a private house, different insulation materials are used:

expanded polystyrene
polyurethane foam
expanded clay
felt, etc.

The process of warming is the same for all materials, so we will consider warming an attic using the example of mineral wool.

Before starting the insulation of the attic, it is necessary to waterproof the roof. Mineral wool is versatile and easy to use, has low thermal conductivity and density, withstands high temperatures well and is insensitive to aggressive environments. Also, mineral wool is an excellent sound insulator.

Attic slopes can be insulated with mineral wool slabs and mats. The slabs are stiffer, and the mats are more elastic, this property helps to fit them better and more tightly. Foil-coated mineral wool mats are also used for vapor barrier.

Since the thickness of the mineral wool is usually greater than the thickness of the rafters, overlays are made on them to increase the thickness. Also, the pre-rafter system is impregnated with an antiseptic solution.

Mineral wool is placed in the gaps between the rafters on the crate and covered with a film for vapor barrier. The vapor barrier film is overlapped on the rafter system. The overlap width of the web is visible on the film - a line is drawn along the edge of the web. The film joints are insulated with special glue and adhesive tape.

Thermal insulation of the floor with expanded clay

Expanded clay should be laid on the floor of the attic on roofing material. The thickness of the expanded clay layer is determined by the thermal conductivity of the floor, but in any case, the thickness of expanded clay should be at least 15 cm, and better - 20-25 cm.

It is known that up to 15% of the heat from the house can go through the ceiling. Therefore, to reduce heat losses, the ceiling is insulated with expanded clay and other materials. Expanded clay not only retains heat, but also increases sound insulation.

Expanded clay is usually used to insulate concrete floors. To do this, it is covered with a layer of 200-250 mm, from above it is poured with a cement screed up to 50 mm thick. The screed will serve as the floor.

The cement-sand mortar for the screed must be of a dense consistency so that it does not flow into the expanded clay backfill.

Mineral wool insulation

Mineral wool should be laid from the far point of the attic.
You need to cut the insulation on a hard surface.
Beams, pipes, ventilation wells, etc. should be covered with insulation.
Mineral wool should be laid in a layer of at least 25 cm.

Personal protective equipment is required when working with mineral wool. These are goggles, rubber gloves, respirator and long sleeves. Do not work near open food and drinking water. Contact with mineral wool on the skin causes irritation and itching.

Insulation with polyurethane foam

Insulation of the attic with polyurethane foam is carried out by spraying on partitions, roof, gables and attic floors, therefore the thermal insulation layer is obtained without seams and joints, that is, a monolithic vapor barrier is obtained.

Polyurethane foam has a low coefficient of thermal conductivity, so the thickness of the polyurethane foam layer is several times less than the layer of mineral wool or foam.

The use of polyurethane foam increases the usable area of the attic space.

The attic, insulated by spraying a layer of polyurethane foam, is not affected by moisture, condensation does not form on the walls, because the polyurethane foam keeps warm air inside. Moisture does not pass through the polyurethane foam and cannot settle on a cold roof.

Insulation of the floor with sawdust is used only in non-residential attics, since when walking, the sawdust will gradually thicken, which will lead to cracks on the concrete screed. The most common recipe for a solution using sawdust for insulating an attic floor:

Ten buckets of small sawdust.
One bucket of cement, grade not less than 300.
One bucket of fluffy lime.
Ten liters of water with an antiseptic. It can be boric acid, copper sulfate, laundry soap.

The volume of water varies depending on the moisture content of the sawdust. The finished sawdust solution is laid in layers of 20-25 cm thick and tamped. All building materials used in the walls of the house must be vapor-permeable. That is, roofing material, polyethylene, roofing felt and other materials that do not allow moisture to pass through cannot be used.

From above, a layer of sawdust is covered with plywood, fiberboard or boards when insulated. The thickness of the sawdust layer on the walls should be at least 15 cm, on the floors and on the floor - at least 25 cm.When the floor is insulated, a cement screed with a thickness of 5-10 cm is made on top of the sawdust.

Insulation of the attic floor of a house allows you to save more heat inside the room, and not spend it on heating a cold attic. It is good if it is used as a utility room (technical attic) or as an attic, but what if not? Then it makes no sense to waste resources on heating an unheated attic space.

That is why it is worth making the insulation of the cold attic floor using heat-insulating materials. It is possible to carry out insulation from the side of the attic or from the side of the room (from the inside / outside). It is best to do this during the construction of the building, or just before finishing the room. But even during the operation of the house, there is no reason not to insulate the ceiling from the attic side.

The thickness of the attic floor insulation is standardized using SNiP II-3-79 "Construction heat engineering". This manual contains detailed recommendations on the selection and formula for calculating the heat transfer resistance of various thermal insulation materials. The calculations take into account not only the type of material, but also the average annual temperature, the duration of the heating season, and the wall material of the house.

The insulation technology of the attic floor depends on the selected material.

In this article, we will look at the most popular insulation materials.

Mineral wool is a heater, the fibers of which are arranged in a certain way. Namely, this randomness leads to the formation of an air cushion between the fibers, which informs the insulation of its properties. However, this same feature of cotton wool increases the ability to absorb moisture. To avoid this, you need to know how to properly install mineral wool.

Benefits of mineral wool:

high density;
long service life;
Fire safety;
ease of installation;
the use of mineral wool for insulating horizontal surfaces does not lead to its caking, slipping and the formation, as a result, of cold bridges.

Among the disadvantages: the ability to absorb moisture.

There are three main ways of laying cotton wool: continuous, in grooves or in cells (see photo). The choice of method depends on what kind of load will fall on the floor in the future. The most stable framework is obtained in the latter case.

First step

It starts with the installation of a vapor barrier film. The film will allow the steam that rises from the warm living room to the cold attic to be removed. To lay the film correctly, you need to carefully read the markings on it. It is imperative to observe an overlap of 100 mm.

If insulation is carried out on wooden beams, then the film should bend around all protruding elements. Otherwise, the beams can rot.

At the junction of the film and walls or other protruding surfaces, you need to raise it to a height equal to the thickness of the insulation plus 50 mm. and glue it with tape or wrap it on an insulation plate.

Second phase

Insulation (cotton wool) is being laid. This is a fairly straightforward process. Plates or strips are easily cut with a construction knife to the required dimensions.

When laying the sheet, you need to make sure that there are no gaps or the mineral wool material is not strongly compressed. Both will lead to a decrease in the quality of insulation. Typical mistakes in the photo.

a) insufficient thickness of thermal insulation material;

b, c, d) the thickness of the attic floor insulation was incorrectly selected.

insulation with foil will increase the material's resistance to heat loss. The sheet is laid with the foil side down.

the insulation should not protrude beyond the beam. If such a situation arises, the beam must be lengthened with a wooden beam or an additional rail to the thickness of the insulation.

a thin insulation laid in two layers retains more heat than one thick one. In this case, the plates must be laid in a checkerboard pattern.

if there are protruding structural elements in the attic, for example, a chimney pipe, you need to raise the insulation to a height of 400-500 mm. and secure it.

Stage Three

Waterproofing flooring is carried out if the attic is not intended to be used, and the rafter system is not protected by a waterproofing film. If the roofing material is separated from the attic with a film, then you can proceed with the final stage.

Rough floor. It is laid on top of the insulation and serves as the basis for the final finishing.

The installation process is similar to the insulation of an attic floor with expanded polystyrene.

The advantages of these materials:

low cost;
simplicity of work;
waterproofness.

Among the disadvantages: flammability.

Attic floor insulation technology with foam or expanded polystyrene

The process of installing rigid insulation based on is more than simple and can be done by hand. The work can be divided into two stages:

leveling the surface. To ensure high-quality insulation, there should be no significant irregularities on the base floor. It is possible to eliminate such drops by performing a screed with a sand-cement mortar.

the laying of the slabs is performed butt-joint or between the beams. The presence of a bar increases the strength of the floor.

Tip: Seal any seams carefully, incl. joints with beams. Bypassing the obstacle, try to cut the holes as accurately as possible. A homogeneous thermal insulation layer retains heat better.

Rough coating

Polyfoam must be protected from destruction with a film in a non-residential attic. In a frequently used or residential attic, you need to somehow move, therefore, it is better to equip a subfloor from OSB or perform a sand-cement screed on top of polystyrene or expanded polystyrene.

Sawdust - finely ground wood.

Advantages:

naturalness;
lack of toxic impurities;
light weight;
availability of material.

The disadvantage is flammability.

Attic insulation technology with sawdust

before proceeding with the insulation with sawdust, they need to be prepared. Namely, mix cement and water with sawdust in a ratio of 10: 1: 1.

Pour the attic floor with the ready-made mixture and level it. It is worth noting that sawdust can be used as insulation without using a frame only in a non-residential attic. Otherwise, when walking on the floor, the sawdust will be compressed, and the concrete screed will collapse.

build a cellular structure from a bar. Pour a solution with sawdust into each cell. The advantage of this method is that a sub-floor can be laid over the timber. And the attic will be usable

Expanded clay is obtained by firing clay.

Advantages:

low thermal conductivity;
naturalness;
environmental friendliness;
ease;
availability.

The disadvantage is associated with the difficulty of lifting expanded clay to the height of the attic.

Expanded clay is usually used if it is necessary to insulate the attic floor on the slabs.

Attic insulation technology with expanded clay

The work is carried out in three stages:

the slab is inspected for cracks and cracks. They are sealed with a solution or covered with thick paper. The protruding elements do not create difficulties with filling expanded clay.

mount a crate from a bar. In the future, a rough floor will be laid on it.

loose insulation is poured onto the stove and leveled using a conventional rake. Layer thickness 250-300 mm. You can move on expanded clay without restrictions.

Advice: when backfilling expanded clay, it is better to combine granules of different sizes (diameters). In this way, the appearance of voids can be avoided.

At the end, a subfloor is mounted or poured with a sand-cement screed.

Please note that the insulation of the attic wooden floor has some nuances:

the tree is subject to decay, which means that the steam that rises up must pass freely. Improper installation of films or the use of non-breathable materials, such as roofing material, will lead to the destruction of the wood in the future.

using foil insulation, you need to place it with the foil down. Thus, the wood will be protected from water ingress and, at the same time, will not accumulate steam moisture.

"Correct" - use a superdiffusion membrane or vapor barrier film

"Wrong" - to lay a special film without taking into account the marking, or even ordinary film

The attic floor insulation scheme for different types of insulation is given below.

Conclusion

In this article, we focused on the main stages and features of the insulation of the attic floors of a private house using various types of insulation. We hope this information is helpful to you.

As many remember from the school physics course, the warm air in the room rises, and the cold air, respectively, descends. It is through the uninsulated attic and the roof that the house loses 15 to 30% of its heat! Usually the attic is insulated when building a house, but if necessary, you can also insulate the attic in a private old house.

Roof insulation

We insulate the attic of a new house

As a rule, they begin to insulate the attic after the roof is completed: the covering is laid, the wind insulation is made. First, the floor is insulated, and if the layer of thermal insulation material is reliable enough, you can take your time with the insulation of the roof slopes and gables.

Keep in mind that you can start insulating the attic of a wooden house only after the building has shrunk. Usually this is done not earlier than six months after the end of construction, although shrinkage can last more than a year. Sometimes, when shrinking, wooden structures are warped or cracks appear in them. Before starting work in the attic, these shortcomings should be eliminated.

For work you will need

Insulation (chipboard plates, mineral wool, expanded polystyrene, polyurethane foam, expanded clay, sawdust with clay, etc.).
Materials for arranging steam and heat insulation:
- vapor barrier foil (polypropylene or polyethylene film, metallized membrane or fiberglass membrane);
- single or double-sided adhesive tape for sealing the seams between foil sheets;
- felt or polyurethane tape for heat and sound insulation of the floor.
Tool for cutting insulation (mineral wool, expanded polystyrene plates) and finishing materials (chipboard, lining, drywall, etc.).
Boards, plywood, lining or drywall boards.
Nails, hammer.
Construction stapler and staples.
Safety goggles, respirator and gloves for working with mineral wool.

Keep in mind that the following methods of insulating the attic are used in cases where it is not heated and is used as a warehouse, summer workshop, etc. However, if the attic will be heated or used as a summer residential attic, slopes and walls should be additionally sheathed with moisture-resistant plasterboard and paint, and lay plates of expanded polystyrene or chipboard on the floor.

We insulate the space under the roof

Many probably noticed that in old village houses only the floor of the attic is often insulated, but not the roof. The fact is that the sloping surface of the gable roof holds the layer of snow well - it serves as an additional "blanket" for the roof. Even in severe frosts, the temperature under the slopes rarely drops below zero degrees. In the attic space, small windows are made that open for ventilation in the summer heat.

In the attic, which will be used as a utility room, the space under the roof will have to be insulated. For self-insulation, it is convenient to use sheet insulation (expanded polystyrene, mineral wool mats) or rolled mineral wool. The density of mineral wool insulation is 10-55 kg / sq. m. Sometimes these heaters are used together: the first layer is fixed with expanded polystyrene, the second - mineral wool.

Before fixing the insulation between the rafters, a vapor barrier foil is nailed onto the crate with a construction stapler. The joints are sealed with insulating tape, but you can also overlap the foil. Foil mineral wool mats can also be used. In this case, no additional vapor barrier is required.

Usually, the required thickness of the sheets of insulation is slightly greater than the thickness of the rafter legs. Make thickening "padding" on them and nail in perpendicular pieces of wood or steel battens. Place an additional layer of insulation between them, then fix it with thin slats, and stuff a wooden covering on top. In residential attics, you can complete the finish with plasterboard.

We insulate the floor

As in the previous case, before laying out the insulation, a vapor barrier is made (for example, from foil-clad polyisol). When arranging a floor slab, the film is laid on top of it; when insulating a wooden floor, it is nailed with an overlapping stapler.

Thermal insulation of a concrete floor. If a reinforced concrete slab serves as the overlap, materials with a high density (> 160 kg / sq. M) are used to arrange thermal insulation. These are mineral wool or cork mats, extruded polystyrene foam, and expanded clay from bulk materials.
Thermal insulation of a wooden floor. Insulation in wooden floors is laid between the logs. Usually these are cotton wool insulation with a low density (< 50 кг/кв.м). Поверх утеплителя желательно настелить рубероид, а в качестве чистового пола уложить плиты ДСП.

Thermal insulation of the attic of an old house

Before starting work on the insulation of the attic of an old house, carefully inspect it. Check for cracks in the rafters and pediments, what is the safety of the floor. It may be that some of the beams will have to be replaced, or it may be necessary to additionally insulate the roof. Wooden parts must be impregnated with special moisture and fire-resistant solutions and an antiseptic solution against fungus and pests.

It is also necessary to perform a number of preparatory work. If the attic of the old house was insulated earlier, and the insulation has not lost its properties, additional insulation materials can be laid on top of the existing ones. For example, on top of a floor insulated with clay and sawdust, you can install a crate and lay mineral wool. Thus, "the initial level of the floor turns out to be" rough ".

Otherwise, the old insulation should be removed, and a new modern one with a higher complex of operational properties should be laid on top of it. After additional insulation, a new final floor is laid.

Features of working with common heaters

Basic requirements for insulation materials:

relatively light weight (this is especially important in houses with wooden floors);
non-toxicity;
ease of processing;
fire resistance;
moisture resistance;
good heat and sound insulating properties.

Modern insulation materials meet all these requirements to one degree or another. The most popular of them are polyurethane foam, expanded polystyrene, mineral (fiberglass and basalt) wool. In brick and stone houses with solid reinforced concrete ceilings, insulation is sometimes used "the old fashioned way". This can be done using inexpensive environmentally friendly expanded clay or clay mixed with sawdust.

Mineral wool

Insulation of an attic with mineral wool is the most inexpensive and at the same time acceptable in quality way of insulating attic rooms. Mineral wool has excellent heat and sound insulation properties, and its elasticity makes it easy to mount on rafters. In addition, it is non-flammable and not susceptible to biological pests. Mineral wool is sold in the form of mats or in rolls.

Mineral wool insulation

The most effective heat insulator is considered to be mineral wool slabs with so-called "randomly oriented fibers". A mineral wool slab with a thickness of only half a centimeter in terms of thermal protection properties replaces almost a meter of brickwork! At the same time, it is light enough and does not create additional load on the floors. Mineral wool is a durable material, its service life is at least 50 years.

When working with mineral wool, remember that it contains a certain amount of formaldehyde. In addition, the smallest mineral wool “needles” are dangerous for the eyes and for the respiratory system and irritate the skin of the hands. Therefore, it is necessary to cut and even more to lay the mineral wool in goggles, a respirator and gloves. Construction masks-respirators can also be used.

Polyurethane foam (PPU)

Polyurethane foam refers to a liquid heat insulator and is applied to any surface (wood, brick, stone, concrete) by spraying. Today it is considered the most effective thermal insulation building material. When processing with polyurethane foam, a durable, bass-based covering is created, so there will never be drafts in the insulated attic.

Insulation with polyurethane foam

By itself, polyurethane foam is an expensive material. However, before applying it, you do not need to do vapor barrier and waterproofing, and working with it is much easier than with other heat insulators. They can handle both the space under the roof between the rafters, and the voids between the logs of the wooden floor, and reinforced concrete floors.

Polyurethane foam can reduce heat loss by almost 30% (in comparison with other materials for thermal insulation). By spending a large amount of money to buy it, in winter you will save twice on heating.

Expanded polystyrene

Inexpensive, lightweight, and durable, extruded polystyrene foam sheets are commonly used in older homes with hardwood floors. It keeps heat well and does not weigh down the supporting structures, it is easy to cut (with a sharp stationery knife or saw) and mount. Its other advantages are moisture resistance (it does not absorb moisture) and environmental friendliness.

To insulate the space under the roof and floor, plates 10-15 centimeters thick are used in two layers. The first is fixed between the logs, and the second is laid on top of them. The structure is fixed with slats, a vapor barrier is laid on top (for example, "Izospan"), and then upholstered with plywood or clapboard.

It is worth insulating the attic with polystyrene foam if you will use it as a technical or utility room. But if you are going to arrange in the attic, for example, a workshop, it is not recommended to use it. This material has little to no noise protection and is unstable for organic solvents that can spill onto the floor or evaporate into the air. Some types of Styrofoam are fire resistant, but in general it is considered a flammable material.

Expanded clay

Expanded clay is an inexpensive and quite effective natural heat-insulating material that is used for thermal insulation of foundations and floors. It can be used in attics with reinforced concrete floors, as it creates a significant load on the beams. An effective layer of expanded clay on an area of 100 square meters, according to GOST, is poured in a layer of up to 60 centimeters, while the weight of the backfill is about 30 tons! In non-residential attics, the insulating layer may be smaller (25-40 centimeters), and in this case they do not make a concrete screed, but it often turns out to be unbearable for the attic floor of a wooden house.

Warming with expanded clay

Insulation of the attic with expanded clay has some features in comparison with other materials. Since this is a porous material that absorbs moisture, not only vapor barrier, but also waterproofing should be laid under the expanded clay backfill. It can be roofing material or ordinary polyethylene film, which is better to be laid with a single sheet, and not welded from several sheets.

It is not recommended to use polyethylene for a wooden floor, since the tree covered with it will not "breathe" - it is preferable to use "Izospan" as a vapor barrier.

For insulation, expanded clay of 10-15 mm fraction is used, which is poured into a wooden frame ("box") made around the perimeter of the room. A vapor barrier membrane is also laid on top of the expanded clay layer. Despite the good thermal insulation properties of expanded clay, experts do not recommend using it specifically for thermal insulation of attics. If the attic is already insulated with expanded clay, its layer is insufficient, but you cannot completely change the insulation, remove the subfloor and lay mineral wool on the expanded clay (under the upper vapor barrier membrane).

Sawdust and clay

In the days of our grandmothers, dry leaves, straw, and hay were placed on the attic floor in order to “keep from blowing”. But the most common and affordable way to make the house cozy was to insulate the attic with sawdust and clay. It is very simple to insulate an attic in a country house or in a wooden cottage in the old way. It is important that this method of insulation will cost you almost free.

Insulation with sawdust and clay

Prepare the solution:

dilute the clay to thickened milk;
add enough sawdust into the solution so that the solution can be mixed. It looks like it will be just wet sawdust, slightly smeared with clay;
pour the mixture on the floor of the attic with a layer of 15 centimeters, level and tamp.

After the mixture dries, you will get a very dense, slightly springy floor covering. From above, you can pour another five centimeters of wet sawdust and tamp it again. A mixture of clay with sawdust keeps heat well, and besides, such a floor "breathes". Fill the floor with a thin layer of lime, and top up with straw, chaff, or dry sawdust.