Options for insulating the attic floor using wooden beams. Insulation of the attic floor using wooden beams and reinforced concrete slabs. The best way to insulate the attic floor.

If you are completing a house, almost the finishing work has already been done and you don’t know whether to take on the attic or whether this matter can wait, and in general what is needed at this stage - this article will help you. Here we will look at insulating attic floors with different types of materials, with step-by-step illustrations, expert advice and useful videos.

We will also reveal many important points about why insulation is so necessary and what an attic floor pie on wooden beams and on a reinforced concrete slab should actually be like - step by step.

What insulation is suitable for the attic?

The attic floor needs to be insulated when the attic space is not planned to be used for housing. Those. we are talking about a cold attic, the roof slopes of which are not insulated at all. But not all the same materials are suitable for covering, so they are selected for slopes.

Mineral wool: no harmful dust

So, when insulating an attic floor with mineral wool, it is correct to use the so-called tension method. Its essence is that the insulating material is first laid - and so that it fits between the beams.

After this, three layers of slab or roll insulation made of mineral wool, with a total thickness of about 150 millimeters, are laid on it, and on top it is covered with a vapor barrier film. After this, it’s plywood, which should be no thinner than 18 millimeters.

Expanded polystyrene and polystyrene: ease of installation

The insulation of the attic floor using expanded polystyrene is also of high quality, the main advantage of which is that there is no need for vapor barrier, and all gaps are easily sealed with polyurethane foam.

Blown-in insulation: fashion and rationality

Recently, insulation of attic floors using the blow-in method has become especially popular.

The main advantage of blown-in insulation is that it automatically fills all the voids that exist and creates an even, continuous layer. In which there are no joints, no seams and no adjoining, and for which there is no need to cut separate small pieces of prickly insulation in order to plug something.

Today, to insulate cold attics in Russia, two types of blown-in insulation are mainly used: ecowool and blown-in wool.

Ecowool consists of up to 80% cellulose fibers, which are produced from ordinary waste paper, and 20% from additives such as Buran as a fire retardant and boric acid as an antiseptic. This insulation has high thermal conductivity.

But blown-in cotton wool is obtained by grinding ordinary mineral materials for thermal insulation, which for some reason did not pass product acceptance.

For example, they did not have sufficient density or correct fiber structure. And such material is crushed and packaged under high pressure, and therefore it is easy to transport it to the site, where everything will be loosened again upon arrival.

But still, ecowool is most often used as a material. The insulation process itself looks like this: one person must remain next to the installation and monitor its normal operation, while simultaneously loading the material. And the second person goes up to the attic with a hose, makes a cross-shaped cut on the vapor barrier (just between the beams), inserts the hose into this cut, and fills the cavity with material.

Plus, relatively inexpensive bulk materials are used to insulate a cold attic:

What insulation parameters should you pay attention to?

We in no way encourage you to purchase the most expensive thermal insulation materials to insulate your attic floor. But note that the more and longer any well-known company produces materials for this purpose, the more it pays attention to quality, changing their volumetric weight, improving their products and increasing thermal insulation coefficients. And this already says something.

Otherwise, always pay attention to the parameters of insulation that are important for a wooden floor, and have no significance for a concrete floor - and vice versa.

Parameter No. 1. Biostability

The point is to ensure that such insulation, which often remains open, does not harbor bugs or other living creatures. This is especially true for mice, which love to live in a warm and dry (and, most importantly, deserted) attic.

Another important requirement for attic insulation is water resistance. Raindrops or simply moisture that accidentally fall into it should not lead to the process of rotting.

Glass wool is recognized as one of the most durable insulation materials:

Parameter No. 2. Thermal conductivity

The main requirements for attic insulation are the ability to maintain thermal insulation properties for a long time.

When purchasing insulation, also pay attention to this interesting point: modern manufacturers of thermal insulation materials always indicate in the technical specifications three coefficients of thermal conductivity of the material: in a dry state, at temperatures of 10° and 25°, and humidity categories A and B.

You need to look at the thermal conductivity coefficient in a dry state, or at a temperature of 10 degrees, because this is the normal climate in the attic. For a more accurate and detailed thermal calculation, you will need a SNiP table.

Now let's note this moment. When choosing when purchasing insulation, you will probably be advised to take insulation with the lowest possible degree of thermal conductivity. But in fact, this only makes sense for residential attics, because when you have to insulate roof slopes, you cannot lay too thick materials between the rafters. Therefore, here we need materials that will conduct heat as poorly as possible, but at the same time have a small thickness.

But for the attic floor, the thickness of the insulation is not a critical factor, and you can save on this. Just take cheaper insulation, but thicker, albeit with high thermal conductivity. Everything is compensated by the height of the insulation itself.

Parameter No. 3. Weight

Depending on the chemical composition, each insulation has its own volumetric mass. Thus, materials such as basalt, glass and any other inorganic and organic compounds are most often used as a basis for fibers. Depending on their type, the heat-insulating material itself becomes either light or heavy. And the shape of all these materials is ensured precisely by the elasticity of the fibers: how they straighten between the floor beams.

Note that heavy insulation materials hold their shape better due to the rigidity of their fibers. And the best stability for insulating attic floors is provided by foam insulation, which in this parameter is equivalent to hard stone wool. But there is a point: the same mineral wool insulation that was inserted between the floor beams can easily straighten out and press tightly against the wood, but foam insulation will not do this, and voids are formed - the bridges are cold. Therefore, you will have to additionally use a can of foam to close all the cracks.

But if you insulate the attic floor on a reinforced concrete slab with foam-based materials, then there will only be advantages. Not to mention the fact that the concrete floor of the attic itself already has considerable weight and creates a serious load on the walls and foundation of the house, and using lightweight insulation for it is just a big bonus.

And unlike a concrete floor, an attic floor can withstand a fairly limited load. Therefore, the weight of the insulation in this regard is also not the last point. After all, there are already many variations here: the same cubic meter of thermal insulation can weigh either 11 kilograms or 350 kilograms – this is the norm.

One of the heaviest insulation materials is basalt wool:

Parameter No. 4. Moisture resistance

Rain moisture that accidentally gets into the insulation or roof leaks should not start the rotting process. It’s bad if after just six months or a year the new insulation begins to decompose from the inside, emitting an unpleasant smell of dampness.

Therefore, insulation of attic floors over wooden beams and concrete is quite often done using polystyrene foam or expanded polystyrene, which are known for their almost zero hydrophobicity.

Parameter No. 5. Environmental friendliness

One more point: the attic insulation should not emit any toxic or pungent odor substances, despite the fact that, perhaps, no one will walk in such an attic.

It's all about ventilation: sooner or later, insulation molecules are picked up by the air and carried into living spaces, which can be unsafe for the residents of the house. Therefore, choose insulation that meets sanitary standards.

Parameter No. 6. Saving the form

Another important point is the form stability of the selected insulation. Thus, special laboratory tests have shown that over time, heat loss through the cracks between the slabs or matte insulation can reach 40%. And this despite the fact that the material itself during the same time may not change its thermal conductivity coefficient at all, if it remains dry.

Therefore, the stability of the shape and size of the material over time is very important. For a concrete attic floor, such gaps will not be critical, because here the floor itself is quite heat-insulating, which cannot be said about the attic floor.

But the problem is that such a parameter as shape or stability cannot be found in the technical information for modern thermal insulators.

Parameter No. 7. Fire safety

And the last point: attic insulation must meet all fire safety requirements. Take the same popular ecowool, which is made not just from ordinary waste paper and pieces of newspapers. It would seem that everything is simple and ingenious, why don’t you also cut the paper smaller and just fill the attic with it? Would it be worse? After all, the principle of looseness is also involved here, like in animal fur, when air molecules get stuck between small elements.

Let's put it this way: yes, the insulating properties of this method will be no worse, but it is old dry paper and wood that most often leads to unexpected fires. That is why modern cellulose insulation is necessarily treated with special chemicals to prevent fire.

If we are talking about the flammability of materials, then it is important that the insulation not only does not burn, but also has attenuation. Just remember that at the epicenter of the fire everything burns, both iron and concrete, but if a spark falls on the attic floor, the insulation should not catch fire. That's what we're talking about.

This is what the attic insulation cake itself should look like:

Vapor barrier issues: how, on which side and is it necessary?

For insulation of wood and concrete roofing, the vapor permeability of the insulation is of great importance. Thus, all insulation materials that are manufactured today in the form of slabs and rolls can be divided into “cotton wool” and “foam,” as construction contractors like to do.

We include thermal insulation materials made of organic and mineral fibers as “cotton” materials - these are mineral wool, stone wool and glass wool insulation. All these materials are formed by the hardening of plastic masses of various chemical origins. And all these materials have approximately the same thermal conductivity coefficient: within 0.04.

All these materials consist of fibers that are intertwined. They do not form any closed pores, and water vapor easily penetrates and escapes through them. Therefore, all cotton insulation materials are vapor-permeable materials. Why, during production, their fibers are additionally coated with a special water-repellent substance, and the insulation also turns out to be hydrophobized: the water molecule from water vapor is not allowed to penetrate inside and wet the insulation. It can only cling to its surface, and when a critical mass accumulates, it transforms into drops and rolls down. It turns out that hydrophobized cotton insulation is not a wet, vapor-permeable material.

Therefore, until now, scientists from all over the world cannot come to an unambiguous conclusion: the vapor permeability of building insulation is good or bad. Let's just say that if you are installing an attic floor on wooden beams, you better lay vapor-permeable materials on it so that the wooden rafters, which take on moisture from the lower living spaces (and water vapor always rises upward), can easily transfer it to the insulation . And they will easily come out of the insulation - just through ventilation is enough. But in terms of insulation of concrete floors, there is not much difference. But there is a point here: when using vapor-permeable insulation, it is important that the ventilation of such an attic is organized according to all the rules, and a separate ventilation system would not hurt.

Note that there are no fibers in foam insulation, since such material is literally produced from thin air. All foam insulation consists of a cellular structure, with closed bubbles and not closed ones, like a kitchen sponge. Therefore, such heat insulators can be either vapor-permeable or non-vapor-permeable. For example, extruded polystyrene foam, which is better known to us as polystyrene foam, allows water vapor to pass between the balls, but extruded polystyrene foam does not.

What’s interesting is that you can use not only one type of insulation, but two at once to compensate for each other’s shortcomings. But at the same time, thermal insulation material with lower vapor permeability must necessarily lie in front of insulation with high vapor permeability. That is, first polystyrene foam, then cotton wool. Otherwise, in the opposite case, a material with less vapor permeability will become a certain vapor barrier for another material, which will simply begin to rot and the moisture will have nowhere to escape.

How to insulate a concrete attic floor

If we are talking about insulating an attic floor made of concrete, then the thermal insulation must necessarily be in the form of two or three layers with overlapping joints of each lower layer. Moreover, it is very important that the entire surface is leveled so that there are no irregularities of more than 5 millimeters anywhere - this is not difficult to achieve with the help of modern leveling mixtures.

For concrete attic floors, extruded polystyrene foam slabs are ideal for thermal insulation. They don’t need a vapor barrier, but if you’re putting in polystyrene foam, it’s not extruded polystyrene foam, and then, of course, it’s needed.

Additionally, if you then need to walk on such a floor, you can make a cement-sand screed up to 4 centimeters and lay two layers of plasterboard sheets. Just be sure to make paths from masonry mesh for such a screed along which you will walk. Be sure to seal the joints between the polystyrene foam boards with tape so that cement laitance does not leak between the boards.

The attic floor itself can be insulated both at the manufacturing stage and at almost any time during the operation of the house itself. Of course, for the attic it is much more correct to insulate the ceiling before you move into your new home.

More details about the process itself:

How to insulate a wooden attic floor

So, there are two main ways to insulate an attic floor: laying a heat-insulating layer inside the attic floor structure, and laying insulation on top of it. For a cold and uninhabited attic, it is not necessary to cover the insulation with something on top and build a full floor. But then be sure to leave walking ladders - separate paths made of sparse flooring throughout the entire area of ​​the attic, this is necessary for roof maintenance.

A vapor barrier must be placed under the insulation, in the form of a trough, so that it can protect the insulation from water vapor that comes from the lower living quarters. But there is an exception to this rule: if the insulation was laid with good resistance, for example, it is foam or extruded polystyrene foam, then a vapor barrier is not needed here. But if we are talking about an attic with a particularly humid environment, for example, above a kitchen or sauna, then a serious vapor barrier layer needs to be installed here.

Another method is tension, when the vapor barrier only sags slightly between the beams. The disadvantage of this method is that the insulation between the beams is not inserted tightly enough.

And if the ceiling is also made from ready-made companies, then this option is not suitable at all, because such voids quickly become so-called cold bridges. Therefore, in Russia, the more popular method is in which the insulation is first laid, then a vapor barrier is covered, and only then with the finishing flooring.

So, here's what the whole insulation process looks like:

• Step 1. A vapor barrier is secured between the beams using a construction stapler.
• Step 2. Next, mineral wool slabs are cut so that their width corresponds to the pitch of the beams.
• Step 3. These slabs are carefully inserted into the gap between the beams.
• Step 4. While the ceiling below is not yet ready, so that the insulation does not fall between the beams, it is supported by rough bars or a strong thread stretched specially for this purpose.
• Step 5. Next, a diffuse membrane is quickly installed on top of the insulation - so that steam can easily escape through it, and drops from above from the slopes do not penetrate inside.

But let us also note the following point about the last step. Many experts believe that no diffuse membranes or windproof films are needed for insulation, because in a cold attic the insulation will dry due to natural ventilation of convection air flows, which easily penetrate through openings and dormer windows.

How to leave walking ladders in insulation

If you use soft thermal insulation materials to insulate the attic floor, you need to make walking ladders over them - but only so as not to create cold bridges. Therefore, it is better to take either hard materials or insert the ladder legs directly into the insulation.

That's all the tricks for insulating attic floors of different types!

Living in your own cottage can be overshadowed by low indoor temperatures during the cold season and high costs. To avoid this, insulate the ceiling of a private house. Using traditional and new materials, ceiling, attic or interfloor insulation is performed.

The process of insulating floors in a frame house using mineral wool

According to the laws of physics, warm air always rises to the top. If it is not heated, heat from the lower floor goes out through it. Heat loss can be up to 40%. Warm air escapes through small cracks in concrete and pores in wooden ceilings. Properly performed thermal insulation will prevent freezing and reduce heating costs.

In all private houses with a cold ceiling, it is recommended to thermally insulate the ceiling. Such work can be performed at the construction stage or in an already constructed house. In the second case, insulation is carried out if the coatings were made a long time ago and over time have lost their heat-insulating properties.

Insulation materials

For thermal insulation, four groups of insulation are used:

In addition to the direct function of thermal insulation, they have. In summer they protect the house from high ambient temperatures. Among the main properties of heat-insulating agents that are important for:

Before making the final choice of thermal insulation product, it is also important to analyze:

1. Climatic conditions. The colder it is outside in winter, the thicker the insulation layer should be.
2. Budget. Quite often the choice depends only on the availability of money.
3. Additional work. What else needs to be done to insulate the ceiling?

Laying mineral wool into beams before covering the ceiling with clapboard

Perhaps this is the replacement of structural elements, finishing materials, the application of additional materials or treatment with fire-resistant preparations.

Sawdust

Sawdust can be used to thermally insulate the ceiling. This is due to its low price, availability, and low cost of work. The main disadvantage of sawdust is flammability and low moisture resistance. This leads to easy fire, rotting, and the appearance of fungus. Therefore, the sawdust is processed before laying.

The process of filling sawdust into the cavity between the beams under the flooring sheets

To reduce the moisture content and prevent mold, sawdust is dried in a special chamber for a year. Later them, fungicides.

Slaked lime will help reduce the risk of rodent infestation. To reduce flammability, they are mixed with fire retardants.

Thermal insulation using sawdust is carried out in two ways. Sawdust is simply poured onto the prepared surface.


This method is not in demand. Since the material begins to shrink quite quickly, which requires regular replenishment. For the second method, sawdust is mixed with cement mortar.

Styrofoam

The slab is breathable, has a low price, does not accumulate moisture, and does not rot. Mold, fungi, and microorganisms do not grow on polystyrene foam. It has high thermal conductivity, resistance to high temperatures, and good sound insulation. Conducts moisture well. Light weight allows it to be installed on thin floors. Durable.

Installation of foam sheets to the ceiling

Main disadvantages:

1. Flammability. This is the main drawback of the material. It is not installed where there is free access to air. When used for floors, they must be treated with plaster or fire-resistant preparations.
2. Rodents. Mice love to make their nests in polystyrene foam.

To prevent the penetration of rodents, use a fine-mesh metal mesh.

Expanded clay

Bulk material is the second most popular insulation material. It has high thermal insulation properties, is always on sale, and is easy to install yourself.

It's inexpensive. Disadvantages of expanded clay:

For installation, large and small particles are mixed. This combination will fill the empty space. To protect against moisture, cement mortar is poured. Its thickness should be no more than 20 mm.

Mineral wool

It is produced in the form of a roll, rolled out over the surface, and cut. The material is inexpensive, has good thermal insulation, and is quick to install. Among its disadvantages are:

The thermal barrier decreases when the cotton wool is compressed, so you should not step on it; the flooring is made immediately after installation.

Penoizol and polyurethane foam

Insulation of this type is poured or sprayed. This material cannot be laid on your own, because... its application requires special equipment, protective suits, and professional skills.

Foam products fill all the smallest cracks and cracks. They do not attract insects, do not burn, and are safe for humans. The substance contains a large number of air bubbles, which contribute to...
Flaws:

1. High price.
2. Fragility. The material does not restore its original shape after damage.
3. Shrinkage. Penoizol has slight shrinkage.

After complete hardening, it is necessary to replenish the settled material.

Insulation technologies

Depending on the structure, the ceiling, attic or interfloor ceilings are insulated.

Ceiling

This type of insulation involves three main steps: preparation, interior work and attic work. The preparatory stage begins with cleaning the surface of debris, dirt, and unnecessary objects. For insulation with mineral wool, polystyrene foam, and sawdust, load-bearing beams with a cross-section of 50 x 100 cm are prepared. They must be checked before installation.

Diagram with the names of the insulation elements of the attic floor in a cottage

Damaged areas are removed or replaced. Mold and mildew are removed using a grinding machine or regular sandpaper. It is mandatory to treat beams with fire and bioprotection agents.
The next step is the installation of utilities.

Detailed diagram of attic floor insulation

The process of insulating an attic includes preparation, laying thermal insulation outside and inside, thermal insulation of gables, and finishing. Bulk materials are not suitable for attic floors.

Insulation is carried out using slab or roll materials. When using reinforced concrete floor slabs, the outer and inner parts of the roof are usually insulated.

First, remove the old flooring and check the rafter system. If necessary, they change parts and carry out repairs. If the logs are thinner than the thermal insulator, they are built up with bars of a suitable size. All wooden elements are treated with an antiseptic and fire retardant.


A vapor barrier membrane is attached to the bars with a stapler so that the smooth surface is on the thermal insulation side. The insulating material itself is spread or laid. Another layer of vapor barrier material is spread on top of the thermal insulator. All seams are closed with tape. The insulation of the attic floor is completed by the production of wooden sheathing for attaching finishing materials.

Watch the video for the process of insulating an attic floor with mineral wool.

Interfloor overlap

Insulation of interfloor ceilings begins with checking the floor level. If differences are noted, it is better to eliminate them using a cement-sand screed. The beams are prepared, all traces of mold are removed, and treated with antiseptic and fireproofing agents. The space between the beams and the structure is filled with foam, and the remains are cut off. A waterproofing or vapor barrier membrane is attached to the beams.

Installed vapor barrier membrane before insulating the interfloor ceiling

They are wrapped in film so that the edges remain open. This will allow them to dry better. The next stage is to install the insulation. For interfloor ceilings, it is recommended to use polystyrene foam or mineral wool. Waterproofing is installed on top of the insulating material and finishing work is carried out at the end.

When ensuring the insulation of 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 cold attic space. Therefore, the issue of insulating the attic must be resolved without delay.

1 Why do you need attic floor insulation?

Insulating a cold attic floor with stone or mineral wool is generally necessary in lightly used rooms that are properly equipped with special roof ventilation.

The attic, or rather its ceilings, serves as a kind of boundary between heat and cold. In such places, the attic floors are exposed to intense moisture due to the formation of condensation.

However, you can properly insulate the floors in the attic of a 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 thermal insulation coating, which will have a low degree of thermal conductivity.

The technology itself for insulating floors in the attic with mineral wool implies strict adherence to its stages and requirements.

The technology itself is quite simple and understandable. Good attic floor insulation using mineral wool helps close unwanted gaps.

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

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

By organizing good insulation with mineral wool, the most optimal temperature will be maintained in residential premises.

If the procedure is performed incorrectly, 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 floors adjoin 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 attic insulation

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 service life of the entire truss structure and roof covering.

The fact is that water vapor located 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 thermal insulation layer, it must always be dry.

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

If the attic space is well insulated, it will not only provide high-quality thermal insulation, but will also help increase the service life of the entire roofing structure.

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

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

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

Before insulating the attic, you need to drain the layer and remove moisture from the entire attic space. To do this, ventilation should be done through windows. They can be:

• Skate like;
• Cornice;
• Slotted;
• Auditory.

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

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

This is the most convenient way 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 beam floors

When implementing such an insulation scheme using mineral wool, heat is retained in the space between the beams. Their usual height is almost always enough for this, but if necessary, several bars are packed on top.

The lower part of the ceiling is sewn up using molding material as with. For this, lining or sheets of plasterboard can be used.

The subfloor covering is laid on top of the beams. This can be a tongue and groove board, plywood sheet or OSB board. Mineral wool is placed on a previously prepared special vapor barrier layer.

An alternative to it can be an ordinary film made using polyethylene. If the vapor barrier material is foil-coated, then it is laid with the 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 insulating layer.

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

Mineral wool 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 reliably protect mineral wool from the smallest drops of moisture, this is especially true if the roof has minor coating defects that cause leaks.

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

2 Why is mineral wool used to insulate an attic?

In most cases, when insulating attic floors, the consumer's choice falls on mineral wool. Its advantage is that its installation does not require special skills.

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 ensured 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. Mineral wool is presented in three varieties; it can be basalt glass and stone.

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

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

2.1 Technology for insulating 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 tiny particles that can enter the respiratory organs and thus cause harm to human health.

During installation, be sure to ensure the availability of personal protective equipment. Goggles, a respirator and thick rubber gloves must be available.

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

Insulation

• Boards and plywood;
• Vapor barrier film;
• Mineral wool (excellent);
• Waterproofing;
• Scotch tape;
• Roulettes;
• Knife;
• Construction stapler;
• Spatula.

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

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

There, in the under-roof space, it will collide with a layer of insulation. Due to the fact that mineral wool is generally considered a vapor-proof material, it will absorb all the outgoing moisture inside itself.

If it is left without the necessary access to air and sunlight, it will gradually dry out and, ultimately, 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, you will need to carefully calculate the required amount of insulation.

The amount of cotton wool purchased depends on how many layers are planned to be used when covering the attic space. In addition, the thermal insulation thickness parameter directly depends on the climatic conditions in the region.

2.2 Proper insulation of the attic floor (video)

Heat, as we know, rises. And he safely leaves the premises through an uninsulated attic.

Losses in winter can reach up to 15%.

To eliminate these losses, regardless of the purpose of using the under-roof space, insulation of the attic floor using wooden beams is required.

Attic insulation is a whole complex of works, which, subject to technology and requirements, meets a number of criteria:

• High-quality thermal insulation of the attic prevents heat loss and the entry of cold air into the building, which significantly affects heating costs;
• In summer, insulation of attic floors prevents the building from heating up through the ceiling and allows you to maintain an optimal microclimate without resorting to air conditioning once again;
• Insulation in compliance with technological requirements is capable of allowing air to pass through and does not allow condensation to accumulate in the attic;
• The use of hydro- and vapor barriers protects wooden structures from the appearance of mold and mildew, which significantly increases their service life;
• Properly performed attic insulation work prevents the formation of ice and icicles.

Technology for insulating attic floors

After laying the wooden beams, the floor is waterproofed. It prevents moisture penetration and additionally protects the insulation.

The waterproofing material can be a multilayer reinforced material made of polyethylene or polypropylene.

The ideal option for fastening the waterproofing is considered to be fastening under the beams in a continuous layer. If this cannot be done, the installation is carried out overlapping between the beams, overlapping the wooden structures, and secured with tape on top for tightness.

Direct insulation of the attic floor over wooden beams is carried out by laying heat-insulating materials between them.

When using bulk raw materials, the filling of all voids and the evenness of the surface are controlled. If the thickness of the insulation used is greater than the width of the wooden beams, additional installation of sheathing is required, fixed across the supporting structure.

In addition, it is necessary to provide options for covering the beams themselves with heat-insulating material to eliminate “cold bridges.”

Regardless of the type of finishing coating, it is advisable to lay another layer of waterproofing on top of the thermal insulation.

The floor of an insulated attic is made of boards laid across beams, plywood, and chipboard.

Video tips:

Insulating the attic with mineral wool

Mineral wool is a fairly popular raw material as a thermal insulator for floors. The material is cheap, non-flammable, can withstand fairly high temperatures, retains heat well and is easy to use.

Disadvantages include susceptibility to moisture, which requires good waterproofing when using it.

Found in rolls and slabs. Both types are suitable for thermal insulation. But the use of a roll version allows you to simultaneously cover beams. Laying is carried out close to the guides, trying not to crush the mineral wool.

Mineral wool is easy to install, so it is in demand for DIY projects. It is mandatory to use protective equipment when working with mineral wool.

Clothing that covers all parts of the body, gloves, as well as a respirator and goggles are required.

Polyurethane foam as an attic insulator

If you choose the ideal insulation based on quality characteristics, then polyurethane foam will lead the leaders.

The raw material retains heat excellently, is non-flammable, durable, lightweight, resistant to external influences, non-hygroscopic, and uninteresting to rodents.

But all its advantages outweigh the cost of raw materials. In small towns and villages, purchasing such insulation is problematic.

If a decision is made in favor of the characteristics, it is necessary to decide on the type of polyurethane foam insulation.

It is easier to install ready-made slabs made from this raw material, but this method has the disadvantage of joints and uncovered beams.

Polyurethane foam in the form of foam is applied by spraying and penetrates into all possible places. A thin layer is enough to obtain a protective effect.

Spraying polyurethane foam requires special equipment and certain skills.

So is polystyrene foam good?

Laying foam plastic slabs to insulate the attic floor between wooden beams can be done even by a novice, inexperienced, self-taught builder.

Installation is carried out on top of the film, tightly adjoining the slabs to each other and to the floors. The gaps are sealed with polyurethane foam.

A waterproofing material is laid on top and finishing is done.

The popularity of this insulation is dictated by its low cost, thermal insulation qualities and ease of installation.

All advantages are crossed out by the fire hazard of the raw materials. In addition to the low melting and ignition temperature, foam releases gases that are hazardous to health when heated.

Therefore, insulating wooden floors with foam plastic is not the best option. This heat insulator is more suitable for concrete slabs and exterior finishes.

Insulation with bulk materials

For bulk insulation, expanded clay or sawdust is used. Both heat insulators are environmentally friendly natural raw materials that retain heat well.

For backfilling, sheathing is installed in the attic. The bulk layer reaches 250–300 mm. A finishing board or plywood is laid on top.

Video on the topic:

When using expanded clay, it is necessary to carry out additional calculations on the load-bearing capacity of the floors. Expanded clay is not a lightweight insulation material and the ceiling may not withstand the load.

Sawdust, despite its apparent ease of use, requires additional processing and is not poured in its pure form, but a special composition is prepared, in which sawdust is only one of the components.

To prepare the solution, the following materials are required:

• 10 parts sawdust;
• 1 part lime;
• 1 part cement;
• 5–10 parts of liquid with an antiseptic.

The choice of heat insulator for the attic and the technology for its installation depends on the required insulation characteristics and financial capabilities.

In any case, even minimal insulation will protect the structure and save on heating costs.

Heating the ceiling of a cool attic

Since the roof of a cool attic serves only the function of protecting against rain, snow and partial wind, special attention should be paid to insulating the soil. Thermal insulating heating is carried out using various thermal insulation materials with mandatory organization of wind protection, especially from the roof.

Thermal coating in two layers with mineral wool cylinders

Installing insulation is usually done directly on the floor of a cool attic.

Of course, if the attic doesn't work. This will save on a layer of waterproofing film, as well as on organizing a complete floor covering.

Read below to learn how to insulate an attic ceiling and what materials can be used for this.

How thick is attic insulation?

The thickness of the thermal insulation layer does not depend on the construction of the attic ceiling on wooden beams or reinforced concrete.

Is there a thermal conductivity coefficient on the packaging of any insulation? And it has two meanings: A - for a dry environment and? B is for wet. The lower this coefficient, the better the insulating properties of the material.

Based on this value, the insulation of the lower part of the attic is calculated.

Attic insulation thickness:

where R0 is the heat transfer resistance coefficient, which is 4.15 m in the standard? °C/W.

Floor heating over wooden beams

Most small houses and villas with cold roofs use wooden ceilings, so their thermal insulation is what we will look at first.

Installation of a ceiling on wooden beams is usually carried out as follows:

1. Ground floor;
2. Vapor barrier;
3. The beams overlap;
4. insulation;
5. Waterproofing;
6. Completion.

The ceiling installation in a private house with a cold attic begins with the installation of load-bearing beams.

Since they usually have a maximum length of 4 meters, it is necessary to build supports or use metal programs for larger areas.

Diagram of a wooden attic device by laying the heater in two layers

Once the beams are laid, a vapor barrier is created that blocks the cold attic. To do this, a vapor barrier film is attached to the bottom, which protects the insulation from moisture penetration from the lower room.

When you are performing rigid insulation on a floor, as with film, it is advisable to use special reinforced laminates made of polyethylene or polypropylene, as they are stronger and more firmly attached.

It is best for the protective layer to be hard.

However, building a wooden attic does not always allow this. If for some reason you are unable to place a vapor barrier under the beams, the film is placed between the two overlapping c's and secured with special adhesive tape to ensure a seal.

A wooden attic structure poses a risk of damage to supporting structures due to rotting.

Therefore, before the furnace is placed in a cold attic, wooden beams and strips are impregnated with special solutions that prevent the formation of rot and mold.

The attic roof is then insulated on beams, for which thermal insulation material is placed between them.

If you use loose insulation, it should be carefully aligned and tracked to fill any gaps.

The minimum thickness of insulation for attic insulation on a wooden floor, calculated using the above formula, may be greater than the width of the supporting supports. In this case, the correct size is attached to you.

Then another layer of insulation is laid between them, with the obligatory covering of the joints of the previous layer.

The fact is that they are formed by so-called cold bridges, due to which it loses heat in the house.

Mansardi wood beams typically work with floor decks of regular treated stacked box panels or cross beams.

However, thick plywood, particle board, MDF and other similar materials can also be used as the final covering.

If you want to use a leveling screed as a finishing layer, the cold attic above the insulating layer must be watertight.

Heating the attic over a reinforced concrete slab

If you need to insulate your attic over reinforced concrete slabs, you can do it in two ways: with or without a box.

The first method is universal, but is most often used for light types of insulation.

In the attic in this case you will see:

1. The vapor barrier is carried out in a cool attic, which should cover the entire layer of insulation, even on the sides.

   Since the vapor barrier must be easily installed on the floor, there is no need to use special materials for this purpose - inexpensive polyethylene film will usually be made.

2. At the top of the film, a wooden stick with a width equal to half the required thickness is placed on the narrow side, which should have a cold attic heater.

   The distance between the rods is usually equal to the width of the cylinder or panel of the selected brand of insulation.

3. Among the boards is an attic heater. If the thickness requires more layers of thermal insulation material, it is laid by overlapping the joints of the previous layer.
4. They are completely identical to the already installed sticks. at the same distance from each other. Between them is a second layer of insulation in the attic.
5. Waterproof cool attic waterproofing installed on top.

   which is secured either with a special adhesive tape or with a thin stick adapted along the box. This level can be lowered if high-quality waterproofing of a cold corrugated roof has already been completed.

6. Sex lanes or traffic bridges are connected through sticks.

Since it is important that the ceiling under a cold roof is sufficiently insulated to save on heating costs in the home, I recommend using an overlay insulation system.

This decking will minimize the possibility of cold bridging across the wood studs since most of them will be insulated by the heater.

Another method of heating a cold attic of reinforced concrete slabs without using boxes is suitable where they are used to insulate solid, wet insulation that can withstand heavy loads without loss of property.

Scheme of a pressure block on a reinforced concrete block

In this case, the first section is in the attic.

The insulation of the attic plates is then completed with a layer of thermal insulation of the designed thickness.

A leveling screed is poured onto it. Estrich is already covering the first floor.

If the insulation of a concrete attic is made of aerated concrete and similar density and properties of materials, you can dispense with hydro- and vapor barrier and screed.

Attic Heater: Which Choice?

Before you insulate your attic roof, you must remove the insulation material that matches your enclosure.

Unfortunately, there is no universal option; it is better to insulate the attic. This choice depends on a number of factors, the most important of which are:

• Thermal insulation properties of the material;
• Fire safety;
• Expenses;
• Easy to install;
• Environmental compatibility;
• hygroscopicity;
• Power;
• Resistant to fire, temperature, acid and alkali.

You need to decide which of these factors is most important to you and which you can ignore.

Heating the first floor of a cool attic with mineral wool

Mineral wool is one of the most popular materials for floor insulation.

The best features of home attic insulation are the varieties based on basalt fibers called stone (basalt) cotton.

Insulation based on basalt fibers belongs to the class of non-combustible materials with a melting point above 1000 ° C; and has excellent thermal insulation properties.

Heating the attic on wooden beams - 5 levels of ceiling insulation work

However, it easily absorbs moisture, so the requirements for hydro- and vapor barrier are particularly high in use.

Drain in two layers of mineral wool between the warmth of the attic

Heating the mineral wool overlay is best done using rollers, since the joints between the plates are not strong, but they reduce the effectiveness of the thermal insulation. If you want to fold it, you need to close the beams close or direct it without disturbing the interference.

Installation of mineral wool is very simple, which is why this insulation material is most often chosen when people want to insulate their attic themselves without the help of experts.

While working, do not forget to use personal protective equipment: thick rubber gloves, goggles and clothing that cover the entire body. For people who are prone to allergies, this kit should be supplemented with a respirator.

• Fire safety;
• Environmental compatibility;
• Ease of use;
• Relatively low price.

flaws:

• Possibility of forming fillings, good wrinkles;
• Hygroscopicity.

Insulating the bottom of the attic with foam.

However, all its advantages are offset by one drawback - this material is a fire hazard.

Already at a temperature of 80 ° C; polystyrene melts, releasing a huge amount of harmful substances at a temperature of 210 ° C; there is fire. Therefore, insulating the attic over polystyrene foam carriers is not a good idea. However, it can be used in non-combustible materials, such as when they are laid on a concrete block by casting as concrete.

flaws:

• nausea;
• Highly flammable;
• It is already deformed at 60°C;
• This is an excellent mosquito refuge.

Heated attic with expanded polystyrene foam

However, insulating wood floor slabs is not recommended.

Despite the fact that open ignition of this thermal insulation material occurs at a fairly high temperature, fire is still dangerous. Firstly, extruded polystyrene supports combustion, and secondly, it releases highly corrosive and toxic substances by heating at very low temperatures, causing death in most cases in a fire. Therefore, penoplex is far from a better option than insulating the attic of a house, although it is reinforced.

• High thermal insulation properties;
• Resistance to humidity;
• Resistant to decay;
• High density;
• A light weight.

flaws:

• When heated above 80°C; it begins to release toxic substances;
• Fire;
• Deforms when heated.

Heating the attic of a house using polyurethane foam

flaws:

Heated ceiling of a cool attic with sawdust

Previously, due to the lack of other materials, cold roof insulation with sawdust was widespread.

Now this method of thermal insulation is used by those who love environmental compatibility. In this case, despite popular belief, designing an attic using such a heater is not cheap at all. Sawdust is not placed “dry”, but in a special solution, the production of which requires money and a lot of time.

The structure of a sawdust solution for insulating a cold attic is as follows:

• 10 tablespoons (wood is necessary, which is formed when cutting and processing wood, furniture dust is too small for this purpose);
• 1 bucket of hydrated lime (thrusters);
• 1 bucket of cement;
• 5-10 pieces of water with antiseptic.

  for example, with boric acid, soap or copper dome (gradually poured into the feeding vessel, the final amount depends on the size of the sawdust).

The resulting mixture is placed on a substrate between the beams and wrapped. The thickness of the layer of such insulation for the attic ceiling should be at least 300 mm, but it is better to do more, because the thermal insulation properties of sawdust can vary greatly. Moving bridges are installed on top of this attic-covering heater, which can be used as particle board leaves or thick plywood.

• Comparatively cheap;
• Environmental compatibility;
• Good thermal insulation properties.

flaws:

• Intensive independent production;
• The thickness of the attic is large;
• Complex installation;
• Differences in thermal insulation properties depending on the composition.

Thermal insulation of the lower part of the attic with expanded clay

Another relatively cheap material that can be used to insulate an attic in a private home is expanded clay.

It is made of baked clay and is one of the most environmentally friendly building materials. In addition, expanded clay has good thermal insulation properties, is stable, durable and inert to acids and alkalis.

With expanded clay you can insulate reinforced concrete and wood attic floors. But in the latter case, the calculation of the load-carrying capacity of the carriers must be carefully weighed, since expanded clay insulation weighs much more than modern insulations.

Concrete floor slabs simply carry very high loads, so they can be used without additional calculations.

A layer of expanded clay insulation covered between attic roof beams

If the wooden attic of the house is insulated, the bar is first made at the top of the beams, and only then the insulation is poured out.

Spread the clay in a layer of 250-300 mm and level it thoroughly. It is then covered with floor boards.

If you are insulating concrete attic floors, waterproofing the coating with filler or coating materials, then the expanded clay is mixed with cement and filled with a layer of 350-400 mm.

• Environmentally friendly material;
• Good thermal insulation properties;
• Fire;
• Resistant to acids and alkalis;
• Not subject to rotting;
• constant;
• Low cost.

On the materials pages: http://oprofnastile.ru

During the cold season, 25 to 40% of the heat is lost in a heated room. To avoid heating the streets in the future, at the initial stage of construction it is necessary to decide how to properly insulate the ceiling under a cold roof.

An insulated ceiling performs three important functions:

1. By its composition, the insulating material is a sound insulator.

   He's a good supporter.

2. During the cold season, insulating material keeps the room warm.
3. In summer, the heater creates a thermal insulating effect without entering hot air.

With the development of construction technologies, new materials, tips and methods for making ceiling insulation in the house. To choose the right material based on your budget and stacking complexity, consider several options.

If you choose an insulating material, you should consider some properties:

1. Thermal conductivity.
2. Water resistance.
3. Material security.
4. Durability of operations.

The following materials are widely used to insulate the ceiling and attic:

• mineral wool;
• sawdust;
• expanded polystyrene;
• polyurethane foam.

Previously, straw or hay were used instead of these heaters.

Some craftsmen still use them, but insulation requires compliance with installation technology.

Ceiling insulation is lightweight and does not overload the roof structure.

Mineral wool insulation material

Mineral wool is the leader among all materials that insulate the ceiling.

It is used for heating inside the house and attic, according to the data, which is excellent for this.

Glass wool

This insulation is made from molten high temperature glass with fine fiber extraction.

In addition, continuous foil and roll-to-roll are formed. Glass wool has weak thermal conductivity properties, such as basalt insulation, but there is much more to casting. It is commonly used for attic insulation.

To install glass wool we only need the interior of the attic, so it is not advisable in rooms.

Polyurethane foam

This material is used by spraying, special equipment is needed for polyurethane foam insulation.

If necessary, it can be dispersed in several layers, which is why it is often used in northern regions. When sprayed, polyurethane foam fills the entire space and forms a tight, sealed lid without stitches.

After choosing the insulation material, you can continue with the main task - how to properly insulate the ceiling under a cold roof.

Also read: How to insulate an attic floor

Ceiling insulation from the inside

You can do this in two ways:

1. Bonding onto ceiling slabs for thermal insulation and fixation with special clamps.
2. Making a special container made of wood or metal on the ceiling and laying insulating material between the guides.

If you want to warm up either option, you need to do some prep work, otherwise the insulation won't have the desired effect.

Ceiling preparation

The installation of the ceiling depends on the material from which it is made.

A wooden ceiling requires the following parts:

1. The entire surface of the ceiling must be cleaned with an antiseptic and fire-resistant material.

   Coat the wood surface with antiseptic to slowly treat each slot.

2. Then you need to fix any cracks. If there are large cracks between the plates, they can be sealed with whales, but it is better to use foam, and when the foam has hardened, the excess part is cut with a knife.

Concrete ceiling

The concrete ceiling is prepared in different ways:

1. If the ceiling has decorative elements, they should be removed and any plaster that can be cleaned should be cleaned.
2. Cracks on the surface must be widened, thoroughly cleaned of dust and prepared.
3. Small gaps can be closed with liquid cement mortar or sealant.

   We heat the attic above the wooden beams

   Large cracks should be sealed with foam. After hardening, the foam is leveled according to the level of the entire surface.

4. The ceiling is covered with an interior base designed for use on concrete surfaces.

   After complete drying, installation work on insulation should begin.

Installation with glue

To heat using this method, all materials will be made in the form of plates of different sizes. This can be basalt wool, expanded polystyrene, expanded polystyrene.

Cement-based mortar and prefabricated foam should be used as glue.

The glue on which the cement is based is prepared according to the recipe on the package.

Pay attention to the specific drying time as it affects the amount of solution required for mixing.

If you choose precast foam, apply it to the heater with a special gun.
The panel with the adhesive attached should be pressed against the ceiling and held for about a minute.

After installing several heater squares, there are holes in the ceiling designed to attach a mushroom to which a spacer nail is later launched. If there are gaps between the plates, they must be carefully filled with foam. The basalt wool heater is installed in a similar way.

This method is carried out under suspended ceilings.

Installation between rails

Thermal insulation with a container is used if plasterboard or lining will be covered by the ceiling.

You should first place marks on the ceiling to give up the lines where the container pieces will be attached.

They should be located at a distance corresponding to the width of the insulation.
The wooden frame is attached to the ceiling with screws. The metal profile is fixed with special springs, which allow the hopper to lower to the required distance from the ceiling.

Next you need to install the insulation. The wooden rods are built by the enemy.

The mineral wool itself is well distributed and has, and it can also be grabbed by shelves with pendants.

The foam is installed very carefully as it can interrupt the panel with a good load.

If after installing the heater there are gaps between the box and the foam, they should be filled with pre-assembled foam.

After installing the insulation, the ceiling should be covered with vapor barrier film. It is attached to a wooden frame with staples or staplers and to a metal profile using double-sided construction tape.

The stretched vapor barrier film is finally covered with sheets of drywall or backing.

The hybrid plates are attached to guide screws with an inclination of 150 mm. The seams between them are reinforced with mesh and applied to the coating layer. After drying the joints, you can fill the entire surface of the ceiling and then finish the finishing work.

Are you insulating your house for winter and don’t know how to insulate the attic floor using wooden load-bearing beams? Having gained experience in this matter, I will accurately convey the technical aspects of thermal insulation, and also describe step by step the procedure for carrying out the work.

Why insulate an attic?

We must not forget that a significant part of heat loss occurs through the roof. Therefore, when constructing buildings with cold attics, it is very important to pay attention to proper thermal insulation of the ceiling between the heated room and the attic.

Below I will try to explain in an accessible language how attic insulation affects the internal microclimate and overall heat loss in the house:

1. Purpose of the attic. Any unused attic under a sloping roof is, in fact, a buffer technical floor between the street and the living space. Its purpose is to smooth out significant changes in air temperature inside the house and outside;
2. Temperature conditions. At any time of the year, during the day the air temperature inside the attic will be several degrees higher than outside. Thus, in winter there will almost always be negative temperatures in the attic, and on sunny summer days there will be intense heat;
3. Heat losses in winter. When the temperature of any substance increases, its density always decreases. Therefore, in heated rooms, heated air from household heating appliances always rises up to the ceiling. If the ceiling has insufficient thermal insulation, then during the cold season, all the heat from the room will go outside through the attic;

1. Excess heat in summer. On hot summer days this process will occur in reverse. The air in the attic will become very hot from the hot roof in the sun, and then transfer its heat through the uninsulated ceiling into the apartment.
2. Reverse air circulation. After touching an uninsulated ceiling, the heated air quickly cools down, and due to the increase in density, it sharply sinks down. Indoors, this leads to excessive reverse air circulation and the constant formation of drafts, which have an adverse effect on the health of residents;
3. High humidity. When heated, humid air comes into contact with a cold, uninsulated ceiling, small drops of condensation may form under the ceiling. This will lead to an increase in air humidity in the house, and will also contribute to the appearance and development of mold on the walls and ceiling;

1. Economic factor. Confirmed heat loss through an uninsulated roof is at least 20-30%. This means that proper insulation of attic floors using wooden beams will save up to 30% of fuel during each heating season. Air conditioning in summer will also require lower costs;
2. Damage from a “warm” attic. Among other things, the penetration of warm air into an uninhabited attic, from time to time, can lead to unpleasant consequences:

• As warm and cold air mixes, condensation will begin to form in the attic. Drops of water will settle on all surfaces, which will lead to rotting and destruction of the wooden supporting structures of the roof;
• From the warmth of the attic, the snow masses on the roof slopes will gradually begin to melt. Thawed water will freeze as it flows down. This can lead to the formation of large icicles along the edges of the roof, as well as freezing of rain gutters and downspouts.

All the factors described are typical not only for residential buildings. They should be taken into account when designing and constructing any outbuildings on the site in which the heating system will be used (for example, a garage, bathhouse, barn, etc.).

Stage 1: Selecting insulation

When choosing materials for ceiling insulation, you should be guided by several criteria. In addition to low thermal conductivity, attic insulation must have the following qualities:

• Moisture resistance and mechanical strength. The material should not be deformed or destroyed under the influence of mechanical load, and should not change its properties in the event of direct contact with water;
• Heat resistance. The insulation must be absolutely non-flammable and should not be destroyed under the influence of high or low temperatures;

• Light weight. In order not to create additional load on the load-bearing structures of the building, the thermal insulation of the attic floor should be quite light, so you need to choose insulation with a low specific gravity;
• Vapor permeability. To ensure normal temperature and humidity conditions in residential premises, all finishing and building materials must freely allow air and water vapor to pass through;
• Environmental Safety. Insulation for residential buildings must be hypoallergenic and chemically neutral. It should not contain harmful volatile compounds or toxic substances;
• Lack of organic matter. I recommend using exclusively mineral or polymer based materials. They do not contain organic substances, therefore they are not susceptible to mold, and are not suitable for food for small rodents and pests.

Taking into account all these factors, several types of thermal insulation materials can be used to insulate attic floors:

1. Mineral wool. Produced in the form of rolls or rigid mats, from intertwined frozen fibers of molten sedimentary rocks. Mineral basalt wool is characterized by all of the above qualities, so it can be considered the most suitable material. Below I will give some recommendations for its use:

• Basalt wool itself is very soft. To prevent it from being pressed or dented while walking, plank flooring should be laid on top of it in the attic;
• When choosing insulation, I advise you to give preference to rigid slabs that are covered on one side with aluminum foil;
• They need to be mounted with aluminum foil inside the room. It simultaneously reflects heat and acts as a vapor barrier layer.

1. Glass wool. It has a similar manufacturing technology, only molten glass is used as the raw material for its production. I do not recommend using this material for insulating residential buildings for the following reasons:

• Glass fibers are more fragile, so they can break under load;
• The price of glass wool is much lower, but after creasing or getting wet, it partially loses its heat-insulating properties;
• Small particles of glass penetrate deeply into a person's skin and cause severe irritation.

1. Expanded clay. This bulk insulation is produced in the form of small round pellets of light brown or red color. Expanded clay balls are formed as a result of sintering special varieties of red clay under high temperature conditions.

Expanded clay has the following characteristic qualities:

• The internal structure of the material has many closed pores, so it has low thermal conductivity;
• Each pellet is covered on the outside with a dense glassy layer of baked clay, so moisture practically does not penetrate inside it;
• Small crumbly expanded clay pellets freely fill the entire volume, so they are convenient to use for insulating hidden cavities and hard-to-reach places in building structures;
• Thanks to its mineral base, this material does not burn at all, does not emit harmful substances, is not susceptible to mold, and is not suitable for rodent food.

1. Styrofoam. This polymer thermal insulation material is made by hot molding from small round granules of polystyrene foam. It is usually produced in sheets measuring 1000x1000 mm, which can be from 10 to 150 mm thick. The following features are characteristic of polystyrene foam:

• Of all existing types of insulation, it has the lowest thermal conductivity;
• The foam contains no organic substances, so it is absolutely not afraid of water, does not rot and does not contribute to the formation of mold;
• By itself, polystyrene foam does not burn and does not support combustion, however, when exposed to high temperatures, it can emit toxic gases and acrid thick smoke;
• Due to the polymer base and closed porous structure, foam sheets do not allow air and water vapor to pass through. For this reason, it is not very good to use for insulating living rooms and rooms with high air humidity.

1. Extruded polystyrene foam Abbreviated as EPPS. It has the same composition as polystyrene foam, but is made by hot extrusion from a molten mass of polystyrene foam. The technical characteristics of these two materials are also very similar, however, EPS still has some differences:

• Expanded polystyrene has a porous, uniform structure and a higher specific density;
• Due to this, it has higher thermal conductivity, but at the same time is more durable, and therefore is able to bear higher weight loads;
• For this reason, I recommend using it for insulating unheated attics that will be used for storing seasonal items or household equipment.

1. Foil polyethylene foam. It is also called “Penofol” in another way. This roll material consists of thick polyethylene foam film, which is covered on one or both sides with a thin layer of aluminum foil. I recommend using it in combination with other types of insulation, because by itself it has specific properties:

• The porous structure of polyethylene foam provides a low heat transfer coefficient, so it functions as an additional insulation;
• Polyethylene film does not allow air, drops of moisture and water vapor to pass through at all, so Penofol can be used as waterproofing;
• Mirror aluminum foil reflects infrared heat waves well. In other words, it does not allow radiant heat to pass through itself, and returns it back to the room.

1. Wood sawdust. This cheap and accessible material is still often used to insulate ceilings in bathhouses, heated barns or small country houses. It is applied to the wooden floor from the attic side, in the form of a homogeneous thick mixture of sawdust with a liquid clay solution. Despite the seeming primitiveness of this method, it has its advantages and disadvantages:

• Sawdust or small shavings can be bought inexpensively, or even taken for free, at almost any large sawmill;
• There can be no problems with clay either, so such insulation is easy to prepare with your own hands in the required quantity at any time;
• The mixture of sawdust and clay has a low specific gravity, and after hardening it becomes quite hard. Therefore, it does not place a significant load on the load-bearing beams, and allows you to walk on it with your feet;
• Due to the mineral components, such a coating is permeable to air and steam, however, due to sawdust, mold may form on it, or mice may chew on it.

All mineral-based thermal insulation materials, to one degree or another, are capable of allowing water vapor and air to pass through. To protect such insulation from the formation of condensation or moisture penetration from the outside, they must be installed using a vapor-permeable waterproof membrane.

Stage 2: Preparation of materials and tools

In addition to insulation, for the work you will need lumber, waterproofing, as well as the usual set of carpentry and carpentry tools:

1. Two hammers: one medium, weighing 200-300 grams, and one heavy, weighing 800-1200 grams;
2. Longitudinal and transverse hacksaw for wood. Instead of a cross saw, it is more convenient to use an electric cutting machine;
3. A carpenter's plane, a large wooden mallet and a set of chisels;
4. As for electric tools, you need to have an ordinary household drill, and it is advisable to have a cordless screwdriver with a set of replaceable attachments;

1. To fasten rolled materials (waterproofing, vapor barrier), I recommend using a construction or furniture stapler with a set of metal staples;
2. You will also need a straight metal ruler, a tape measure 3-5 meters long, a building level and a simple rope plumb line;
3. To work near the ceiling, it is most convenient to use a folding stepladder. If you don’t have one, you can use a high, strong table or homemade trestle made from scrap boards for this purpose;
4. From lumber you will need wooden blocks with a cross-section of 62x62 mm, and planed edged boards with a thickness of 25-30 mm;

1. As a waterproofing layer, you can use a film of foamed polyethylene and a vapor-permeable waterproof membrane;
2. To seal the joints of the panels, you will need metallized aluminum tape, which is usually used in ventilation systems;
3. Each homeowner chooses materials for finishing the ceiling at his own discretion. This could be lining board, drywall, laminated OSB or plywood, or other finishing materials;

If you plan to use mineral or glass wool for insulation, then I recommend purchasing a special protective suit that is designed to work with these materials. Otherwise, severe irritation may occur on exposed areas of the skin from small glass fibers.

Stage 3: Filing the rough ceiling

When building an attic floor or erecting a sloping roof, you can do without expensive and heavy concrete floor slabs. Instead, the entire load from the roof is carried by wooden load-bearing beams made of logs or timber, with a cross-section of at least 120x120 mm. They are usually laid on top of two main exterior walls, perpendicular to the long side of the house.

Such beams serve as a supporting structure for the ceiling of the top floor and for the floor of the attic. The same beams will also be used for installing insulation between the residential building and the attic. This type of ceiling is called hemmed, because both the rough and the finished ceiling are hemmed from below to the load-bearing beams.

Before insulating the attic floor, you need to mount the rough ceiling:

Illustration	Description of work
	Installation of a rough ceiling. To hem the rough ceiling, you should use dry edged boards 25 mm thick, or plywood sheets 10 mm thick or more.
	Hemming boards. They must be secured to the lower plane of the supporting beams and beams around the perimeter of the room. Hemming boards must be fastened without gaps or cracks, close to each other. For fastening, use galvanized self-tapping screws 5-6 mm.
	Waterproofing. When the entire rough ceiling is hemmed to the load-bearing beams, panels of foiled polyethylene foam need to be secured to it from below. This can be done using a stapler. "Penofol" will perform the functions of heat and waterproofing. It should always be placed with a foil layer towards the warm room.
	Sealing joints. To prevent moist air from the room from entering the insulation, the ends of the polyethylene film must be wrapped on the walls by 150-200 mm. The joints between the panels must be glued with metallized tape on an aluminum base.
	Attaching the sheathing. From below, across the entire area of ​​the rough ceiling, nail a counter lath made of wooden slats 15-22 mm thick. It is needed in order to provide a ventilation air gap between Penofol and the finished ceiling. The distance between the slats should be about 400-600 mm. In the future, a finishing ceiling covering will be attached to them from below.

Before starting work, all wooden structural elements must be treated with antiseptic and fire-retardant impregnations. Antiseptics are needed to protect wood from rotting and mold development. Fire retardants give dry wood fire retardant properties.

Stage 4: Installation of thermal insulation

After filing the rough ceiling, the transverse load-bearing beams will be on the side of the attic. Insulation will be laid in between them.

Depending on the thermal insulation materials used, further installation technology may have some differences. Therefore, below I will briefly discuss the use of the most common types of insulation.

1. Laying mineral wool. Mineral insulation materials, when wet, partially lose their properties. To prevent condensation from forming in the mineral wool, the entire thermal insulation layer of the cold attic floor must be permeable to air and water vapor:

Illustration	Description of work
	Vapor barrier. First, you need to lay a vapor-permeable waterproofing membrane on top of the rough ceiling. Its peculiarity is that it freely allows water vapor molecules to pass through, but does not allow bound liquid water molecules to pass through. The membrane panels must overlap each other by at least 150 mm;
	Installation of insulation. Place sheets or rolls of mineral wool in the spaces between the wooden beams. If it is very soft, then it does not need to be squeezed or squeezed much. Lay another layer of vapor-permeable membrane on top of the mineral wool. To prevent it from moving over time, it must be stapled to the beams and walls, throughout the entire area and along the perimeter of the attic.

1. Installation of foam plastic. Polymer-based insulation does not have breathable properties, so it does not allow air and moisture to pass through. There is no point in using a waterproof membrane in this case:

Illustration	Description of work
	Laying foam. Foam or extruded polystyrene panels can be laid between the cross beams, directly on top of the sub-ceiling boards. I advise laying them in two layers, so that the joints of the sheets are located in different places and do not intersect with each other.
	Polyurethane foam. To prevent the insulation sheets from moving to the sides, they can be glued to the sub-ceiling using a special glue for polystyrene foam or polyurethane foam. Thus, it is necessary to fill the entire area of ​​the attic floor with insulation. If there are gaps and cracks between the sheets of foam plastic, then they must also be blown out from a balloon with polyurethane foam.

1. Clay with wood shavings. Insulating the attic floor with a sawdust-clay mixture does not require any additional materials, and is also quite simple:

Illustration	Description of work
	Preparation of the solution. To make the sawdust-clay solution plastic, the clay must be soaked in water 2-3 days before starting work. To prepare the solution, you need to take 3-4 volume parts of sawdust, and 1-2 parts of dry red clay without large solid particles and foreign impurities. Mix the soaked clay with water until a liquid, flowing solution is obtained; Add sawdust to the resulting mixture and mix thoroughly until smooth. To protect against mold formation, a small amount of copper sulfate can be added to the prepared solution.
	Laying sawdust-clay mixture. Lightly moisten the supporting beams and boards of the rough ceiling with liquid clay milk. After this, fill all the gaps between the beams with sawdust-clay mortar and leave for several days until completely dry.

1. Expanded clay backfill. I want to say right away that expanded clay does not have very good heat-insulating properties, therefore, in individual construction, such insulation of floors is rarely used. At the same time, it is considered inexpensive, unpretentious and the easiest to install:

Illustration	Description of work
	Preparatory work. Expanded clay pellets do not absorb moisture, and therefore are not afraid of water ingress or condensation. Therefore, they can be used both with and without a waterproof membrane. To prevent condensation from seeping through the ceiling into the house, I still recommend laying a waterproofing membrane under the pellets;
	Filling of pellets. Expanded clay pellets should be poured on top of the rough ceiling boards and evenly distributed in a thick layer over the entire area of ​​the attic. No covering material is required on top of expanded clay.

To prevent expanded clay pellets from bunching up and spreading throughout the attic, a retaining plastic geogrid is used. It needs to be stretched in the spaces between the load-bearing beams, and then expanded clay should be poured into its cells.

Stage 5: Arrangement of the floor in the attic

Many residents use the cold attic in their private home as a storage room for storing long items, seasonal items and all sorts of unnecessary rubbish. In order for a person to safely walk on the insulated floor, a durable subfloor must be installed in the attic.

The choice of material for installing the floor in the attic will depend on the type of insulation used:

Illustration	Features of application
	Mineral wool and polystyrene foam. These materials themselves are very soft. To prevent them from being destroyed or wrinkled while walking, the top floor covering must be sufficiently rigid. In such cases, OSB or plywood sheets with a thickness of at least 18 mm should be laid on the load-bearing beams. You can also use unplaned edged boards with a thickness of 25 or 30 mm.
	Extruded polystyrene. It has higher rigidity, so it can withstand significant loads. To prevent it from being pressed when walking, it is enough to put a light flooring of thin boards or plywood 5-9 mm thick on top of it.
	Under the weight of a person, they will crawl in different directions. To prevent this from happening, you need to lay 10 mm thick plywood sheets or light wooden ladders made of boards on top of the beam floor.
	Sawdust-clay insulation. After the solution hardens, it becomes hard like cement. A person can move freely on its surface, even without installing additional flooring.

When installing rough flooring in the attic, you should always leave gaps 15-20 mm wide between boards or sheets of plywood. This is done so that moisture and condensation can freely evaporate from the insulation.

Conclusion

Using this operating algorithm, you can easily insulate the attic floor in your own home. More visual information on each method of insulation can be viewed in the attached video in this article, and I suggest leaving all your comments and questions in the comment form.