Detailed technology of wall insulation with foam foam. The principle of thermal insulation of the facade with foam, the necessary materials

Manufacturer Penoplex has developed a number of design solutions for thermal insulation of load-bearing structures of buildings. Individual developers most demand the STO 36554501-012 standard, which allows them to produce with a minimum construction budget. The technology was created specifically for shallow foundations, it makes it possible to exclude freezing of soils under the sole of the cottage, adjacent to the reinforced concrete structures of the layers.

Application of thermal insulation technology Penoplex

Preserving the heat of the bowels along the perimeter of the building is one of the methods for eliminating frost swelling. However, the technology is effective only in combination with drainage, the use of non-metallic materials in the backfill, the underlying layer. The developers of the standards STO 36554501-012 called insulation of the foundation with Penoplex by the TFMZ method (thermal insulated foundation of small depth).

Technology suitable for 1 - 3 storey buildings on seasonally swelling soils with normal design soil resistance. Standard Penoplex boards made of high density extruded polystyrene foam or similar products from other manufacturers that correspond to the XPS class are used.

Attention: With a guaranteed absence of swelling of the sole of the MZLF, columnar foundations are laid at levels of 30 - 40 cm, allowing you to significantly reduce the construction budget. For permafrost, unstable soils, the technology cannot be used.

Design nuances

Suitable for any heaving soils, uses two heat-insulating contours - vertical along the outer surfaces of the foundation, horizontal at different levels (under the base of the foundation + under the blind area). At the same time, different tasks are solved:

Attention: The technology has modifications for cottages of permanent residence (heating in winter), houses for seasonal, temporary operation (without heating or with periodic switching on of the boiler).

Thermal insulation technology step by step

Produced in several stages. Horizontal thermal insulation is laid on top of the underlying layer (sand, crushed stone) before installation / concreting of the foundation. After gaining strength with monolithic reinforced concrete structures, stripping, waterproofing of the outer edges of the foundation tape, pillars, and slabs is carried out.

Extruded polystyrene foam is then glued on top of this protective layer. Lastly, the blind area is insulated. If the project uses technology floor on the ground or it is planned to operate the building seasonally, periodically, the heat insulator is laid around the entire perimeter of the house.

foundation pit

With a foundation laying depth of 30 - 40 cm, taking into account the thickness of the underlying layer of non-metallic material, the depth of the pit is:

To determine the size of the pit, it is necessary to take into account a number of factors:

if floors are laid on the ground in the project, it is necessary to remove the entire arable layer of chernozem in the development spot, since it is impossible to pour the screed on such soil rich in organic matter - it will sag
for heated houses, trenches are torn off, the width of which is equal to the size of the base of the foundation + the width of the insulation of the blind area (0.6 - 1.2 m)
for unheated buildings, a pit is required to the specified depth, the insulation will lie in a continuous carpet

Attention: Expanded polystyrene in the TFMS technology is located under the sole of the foundation structures (without heating), therefore, it is necessary to use only modifications of the high-density heat insulator XPS or XPS to avoid drawdown. The blind area can be insulated with PSB-S materials, which have a lower density and are much cheaper.

Foundation pad, drainage

The underlying layer is necessary to replace heaving soils, level the bottom of the trench / pit, and drain the space around the foundation. It is allowed to make it from materials:

The sinuses of trenches and pits should be filled with the same materials to eliminate the tangential heaving forces that tend to push the foundation to the surface. In both cases, a platform vibrator (vibrating plate) compacts layers of 10–15 cm.

Attention: If crushed stone is used, the surface of the foundation pad must be leveled to the minimum sufficient for this layer of sand. Otherwise, the Styrofoam can be destroyed by the sharp edges of the stones when transferring serious loads from the building that presses on it.

It is produced by plates with a thickness of 5 - 10 cm in one or several layers. In any case, the contour must be continuous, the slots are filled with mounting foam.

Heated cottage

If the dwelling is operated year-round, insulation of the foundation with Penoplex produced according to the scheme:

In the case of overlapping along the beams, the interior of the building is not insulated. Under it, in any case, a positive temperature is maintained, heat loss through the ceiling is prevented by laying thermal insulation between the rough, finishing floor.

Thus, the foundation is covered from the outside with a layer of expanded polystyrene, cold bridges are completely absent.

Attention: If the wall does not have insulation inside, then the expanded polystyrene in the upper part of the basement is brought inside, under the wall material, in order to exclude a cold bridge at the end of the basement.

Building of seasonal, periodic operation

In garden houses, dachas (without heating, with periodic heating, respectively) insulation of the foundation with Penoplex done in a different way:

This is due to the following factors:

Attention: In the corners of the strip foundation, the concentration of reinforced concrete is greater, which causes intense freezing of the adjacent soils. Therefore, two layers of XPS are used here with the capture of straight sections of 0.5 - 1.5 m, depending on the width of the tape, the dimensions of the MZLF.

The main mistakes of the TFMZ

In the lower diagrams, the reasons for the occurrence of cold bridges in the foundation insulation structures, as well as ways to eliminate them, are considered.

In the first case, the expanded polystyrene layer is protected from mechanical damage by brickwork, on which the lining of the basement and facade rests. The continuity of the circuit is broken, which is very difficult to fix later. Therefore, laying should begin on top of the thermal insulation layer of the blind area.

In the second version, the cold bridge is the upper end of the basement part of the MZLF. Correcting the error after facing the facade is also not possible. Therefore, the insulation should be brought inside before the start of the masonry.

In the latter scheme, the cold bridge is the basement section of the MZLF tape not lined with expanded polystyrene. This error can be corrected at any stage of construction, operation.

Thus, the manufacturer Penoplex not only produces high-quality insulation, but also developed standard solutions for all load-bearing structures of residential, industrial, office buildings. This will help the individual developer to avoid design and manufacturing errors.

At present, the demand for effective heat-insulating materials is increasing on the domestic market. As you know, heat loss through the foundation is 10-15% of the total heat loss, and therefore the insulation of the outer walls and basement enclosing structures, as well as the thermal insulation of the floors, are one of the main measures for the thermal insulation of the building. Effective thermal insulation not only improves the microclimate in the room, but also increases the service life of building structures.

The rational use of thermal insulation materials reduces heat loss and reduces the cost of building operation. A modern thermal insulation material must combine low thermal conductivity and hygroscopicity with durability and ease of use. This requirement is fully met by Penoplex heat-insulating boards, which are made from general-purpose polystyrene by extrusion. The only domestic manufacturer of such products, which also occupies the strongest position in the Russian market of extruded polystyrene foam, is Penoplex. To date, the company produces two grades of plates ("Penoplex-35" and "Penoplex-45"), differing in density, strength characteristics and, as a result, application features (numbers characterize the average density of the material - 35 and 45 kg / m3) . Heat-insulating boards "Penoplex" are produced with a width of 600 mm and a length of 1200 to 2400 mm with a straight processed edge and with a quarter.

The process of extruding polystyrene is the production of a foam material with a homogeneous structure, consisting of small closed cells with a size of 0.1-0.2 mm. This structure provides almost zero water absorption. Thus, tests carried out with complete immersion of the material in water for 24 hours showed the percentage of water absorption not more than 0.1-0.2% of its total volume. The same tests, carried out for 30 days, increased this figure to only 0.4%.

At the same time, the coefficient of thermal conductivity of the plates is 0.028-0.03 W / m * K, which is significantly lower than the average values for most other insulating materials. So, for comparison, a 30 mm thick Penoplex heat-insulating board gives the same heat transfer resistance that 40-50 mm thick foam or 50-60 mm mineral wool, or 170-320 mm wood, or 510-740 mm brick masonry.

In addition to the fact that Penoplex does not absorb moisture and has better thermal insulation properties, it has a number of other advantages compared to traditional thermal insulation: it does not shrink, it has high mechanical strength (withstands a load of at least: 25 tons per 1 m2 - brand 35, 50 tons per 1 m2 - brand 45), resistance to deformation, chemically resistant to most building materials and substances, not subject to biological decomposition (rotting) in the environment, does not pose a danger to the environment and human health (all the necessary conclusions are available and certificates), and the addition of effective flame retardants significantly increases the resistance of Penoplex boards to combustion. All physical and thermal characteristics of the material remain unchanged in a wide temperature range from -50 to +75°C. No other thermal insulation material has so many advantages. For comparison, due to its structure, ordinary foam plastic absorbs up to 3% moisture within 24 hours, and over the next 24 days - more than 10% (recall that Penoplex has the corresponding indicators: no more than 0.1-0.2% moisture in 24 hours and not more than 0.4% in 30 days). Consequently, the coefficient of thermal conductivity of the foam is rapidly changing for the worse. After 10-12 years, such thermal insulation is destroyed. Absorbs moisture and mineral wool, which begins to sag in the construction of "well masonry". In Penoplex plates, the low ability to absorb moisture over time remains practically unchanged regardless of humidity, which allows you to work with the material in all weather conditions without any means of protection from atmospheric precipitation.

Rice. 58. Thermal insulation of walls, basements and foundations:
1 - outer wall; 2 - waterproofing layer; 3 - plinth lining; 4 - blind area design; 5 - foundation wall; 6 - "Penoplex"; 7 - plastic sealant; 8 - floor tiles; 9 - cement-sand screed; 10 - concrete base; 11 - technological layer (polyethylene); 12 - gravel base; 13 - soil; 14 - sand and gravel backfill; 15 - drainage pipe (if necessary)

The main consumer of extruded polystyrene foam is the construction industry. About half of the material produced goes here. The design of the floors is essential for keeping the heat inside the building. Through the floors, arranged without thermal insulation, large heat losses occur, as a result of which the operating costs of the building increase. The most common construction of buildings with ventilated undergrounds. The thermal insulation of the floors of the first floors in such buildings can be carried out both after the installation of the slab, and ready-made floor slabs with Penoplex thermal insulation can be used. The advantage of Penoplex boards becomes especially relevant in the construction of "basementless" buildings, when the floors of the first floors are directly on the base. Due to their closed cell structure, Penoplex slabs can be laid under waterproofing membranes on a crushed stone base with a leveling layer of sand with an underlying layer thickness of at least 100 mm. With this method of thermal insulation, there is no need for concrete preparation.

The use of Penoplex is especially effective when insulating loaded floors (in car dealerships, ice palaces, swimming pools), as well as at many private housing construction facilities (winter gardens, greenhouses, garages, in heated floor structures). In the presence of a floor heating system, thermal insulation is absolutely essential. Its function in this case is to reduce heat transfer in undesirable directions. Otherwise, not only your floor is heated, but also the ceiling of a neighbor or basement. Heat-insulating plates "Penoplex" are laid on the floor panel. Directly on them is the installation of a "warm" floor.

Structural elements of the underground parts of the building during operation experience significant physical loads from the effects of temperature factors, groundwater, heat flows, which leads to cracks and destruction. The penetration of moisture into the structure not only creates the prerequisites for early aging, but also reduces its thermal performance. The most reliable and economical when constructing buried foundations is continuous external thermal insulation with slabs of extruded foamed polystyrene "Penoplex". Thermal insulation works can be carried out in parallel with waterproofing works.

In order not to violate the integrity of the waterproofing layer, the plates must be fixed to a vertical surface with bitumen-based adhesives that do not contain solvents. It is enough to apply adhesive compositions pointwise, since gluing is necessary only until the moment of backfilling. When installing insulation of foundations from rolled welded materials, it is possible to glue extruded polystyrene foam boards by melting the outer layer of waterproofing. After the installation of the insulation boards, the foundation is backfilled with soil with layer-by-layer compaction. With this type of thermal insulation, there are no “cold bridges” in the structure. Plates "Penoplex" reliably protect the waterproofing membrane from mechanical damage, which significantly increases its service life.

A massive foundation is not always a protection against the tangential forces of frost heaving of the soil. The resulting deformations lead to damage and even destruction of some building structures already in the first year of operation. When designing shallow foundations, it is necessary to provide for measures aimed not at overcoming the forces of frost heaving, but at reducing the deformations caused by them to the maximum allowable values for a particular building or structure (VSN 29-85). In this case, it is advisable to install less powerful and less expensive shallow foundations (recommended by SNiP 2.02.01-83).

It is recommended to lay a heat-insulating layer with a thickness determined by calculation near the external foundations (under the blind area) at a depth of 20-30 cm with a slight slope from the building, at least 1 m wide. Thermal insulation in this case will additionally ensure the removal of surface water from the base.

The material was provided by LLC "Termopol"

About 20 years ago, the list of heaters was replenished with such material as penoplex. During these years, the new insulation has won the trust of both professional builders and ordinary people.

The manufacturer of the material is the Russian company Penoplex. The insulation itself is a high quality extruded polystyrene foam. It is produced in the form of plates of uniform density. They are distinguished by a porous gas-filled structure with small cells (whose diameter is 0.1-0.3 mm), each of which is isolated from its neighbors. This structure of the material provides sufficient mechanical strength of the plates and high thermal insulation performance.

Wall insulation boards

The company's enterprises produce slabs of various densities and thicknesses, suitable for insulating various building structures.

For thermal insulation of walls, plates of two brands are currently being produced: Penoplex-Facade and Penoplex-Comfort.

By most indicators, they are absolutely identical, but a special flame retardant has been added to the facade material, due to which its fire resistance class is slightly higher. Also, the compressive strength of the front plates is slightly different.

The main characteristics of the plates are given in the table:

Name of indicator	Penoplex Facade	Penoplex-Comfort
Compressive strength (at 10% linear deformation), MPa	0,2	0,18
Density, kg / cu. m	25 — 35	25 — 35
Fire category	G3	G4
Thermal conductivity coefficient, W/(m×deg.С)	0,030	0,030
Temperature range of operation, hail. WITH	-100 to +75	-100 to +75
Water absorption for the first day,% of the volume	no more than 0.5	no more than 0.4
Water absorption for the first month,% of the volume	no more than 0.55	no more than 0.5

A little more about the characteristics of the material:

The coefficient of thermal conductivity of penoplex is perhaps the lowest among all modern heaters. What is important, it practically does not change when the plates are used in various conditions, including high humidity. Such material can also be used for interior work.

The moisture resistance of the material is also surprisingly high. Under any conditions, it absorbs water no more than 0.5% by volume. This mainly occurs in places where the plates are cut. After a month, this process almost completely stops.
The closed nature of the pores does not contribute to the spread of moisture and steam throughout the volume of the plate. Therefore, subject to the installation technology, there is no need to install additional vapor barrier membranes.
The mechanical strength of foam plastic allows it to be used to protect structures such as foundations and floors.
According to the degree of fire resistance, the material belongs to self-extinguishing polymers and does not contribute to the spread of fire. If the insulation is protected by a layer of plaster, this reduces the possibility of its ignition to almost zero.
The material does not decompose even over time and is therefore safe for human health. It also does not rot and has a high bio-resistance.
The plates have precise geometric dimensions, and their edges are equipped with special protrusions that ensure a snug fit of adjacent elements.

Extruded polystyrene foam is resistant to most solutions and compounds used on the construction site. But there is a list of substances that can adversely affect it.

This:

oil paints;
petroleum products - diesel fuel, kerosene, gasoline;
acetone and other solvents of the ketone group;
formaldehyde and formalin;
xylene, benzene, toluene and similar hydrocarbons;
esters and polyesters;
coal tar.

The service life of high-quality foam plastic is about 50 years. But this applies only to the original product. No one guarantees the properties of fakes found on the market.

Therefore, when purchasing a material, pay attention to its color and the company logo printed on the plates, and also check the quality certificate.

Which side do you need to insulate the walls - from the inside or outside

It would seem, what difference does it make where exactly the insulation layer will be located? Indeed, in any case, it isolates the room from atmospheric cold, which means that the house will be warmer.
The difference is significant. Based on the fact that the insulation of the house is carried out in order to improve its internal microclimate, the work must be carried out so that after them this microclimate does not suffer. And this can happen if you approach the matter superficially.

By changing the thermal conductivity of the outer walls with the help of a heater, we simultaneously cause a shift in the dew point, which can lead to the appearance of moisture on the inner surface of the outer walls.

And this, in turn, will cause the appearance of mold and mildew, and can also increase the humidity in the house, making it uncomfortable to live in.

The dew point is the temperature at which the moisture in the air turns into water. Its location directly affects whether the walls in the house will be wet or remain dry throughout the winter period.

The location of the dew point depends on many factors:

material of external walls;
its thermal conductivity;
wall thickness;
temperature and humidity of the internal air in the house;
temperature and humidity outside the building.

Ideally, it is necessary to make a heat engineering calculation of the external enclosing structures, taking into account all these factors.

This will determine exactly where moisture condensation will occur:

in the thickness of the wall;
on its inner surface;
in the thickness of the heater.

Experienced builders will never advise the owner of the house to insulate from the inside, if it is possible to do this from the side of the facade. It is this option that is guaranteed to provide a shift in the dew point towards the outer surface of the wall or even into the thickness of the insulation layer. Then the walls in the house will always be dry, and the microclimate healthy.

If we are talking about our own home, then no one and nothing can prevent the owners from insulating the walls from the outside. It is more difficult with an apartment in a high-rise building - it is impossible to change the appearance of the facade of the building without permission, so the outer wall will only have to be insulated from the inside, from the side of the apartment.

This option requires a more careful approach in terms of calculating the thickness of the insulation. It should be such that the dew point is eventually located in the thickness of the wall, and not on its surface or in the insulation layer, even at very low outdoor temperatures.

Otherwise, you run the risk of getting an eternally “weeping” wall, which will eventually lead to the destruction of the wall material, insulation (if it absorbs enough moisture) and all the attendant troubles.

We will consider the option of external wall insulation with foam plastic, as the most frequently implemented.

The principle of thermal insulation of the facade with foam, the necessary materials

The best way to insulate a house with extruded polystyrene foam is the wet facade technology, when the thermal insulation layer is protected after installation by applying plaster. At the same time, it will also be a decorative decoration of the building.

So, if we consider the outer wall of the house in section, we will see the following layers:

interior decoration of the walls of the room (drywall, plaster, etc.);
directly the wall of the building;

a layer of glue used to fix the insulation boards on the wall;
thermal insulation layer;
protective and reinforcing layer, consisting of an adhesive composition and a reinforcing mesh of metal or fiberglass recessed into it;
layer of decorative and protective plaster.

The reinforcing mesh not only combines the insulation boards into a single structure, but also serves as the basis for applying plaster.

To carry out the work, the following materials will be required:

Insulation plates of the required thickness (thickness must be calculated based on the amount of required thermal insulation). Since the thickness of the foam panels varies quite widely (20, 30, 40, 50, 60, 80, 100, 120 and 150 mm), it will not be difficult to choose the right material. The amount of material should correspond to the total area of the outer walls with a margin of 10%, since the material will have to be cut. The plate size is usually 600×1200 mm.
Primer - used to treat walls before applying thermal insulation. The type of composition and its consumption depends on the material of the walls. If the walls are made of monolithic concrete, then it is better to purchase the Betonokontakt primer for outdoor work, which contains fine quartz sand. If the walls are brick or plastered, then Ceresit CT-17 primer can be used.
Starting profile - necessary as the basis for the first row of plates. Installed on a level at the border of the wall and the plinth, it facilitates the installation of thermal insulation. To fasten and install the profile, you will need accessories such as washers, connecting elements, dowels.
Adhesive composition for working with expanded polystyrene. There are many suitable mixtures on the market. The consumption of the mixture is quite large - about 5 kg / sq. m for sticking plates and about the same for the subsequent protective and reinforcing layer.

Dowel-fungus for additional fastening of foam to the walls. The length of the dowel is selected based on the thickness of the insulation (it must exceed it by at least 45 mm), the dowel consumption is approximately 6 pcs/sq. m.
Reinforcing mesh. Although metal mesh can be used, fiberglass is still the best option, which is not afraid of alkaline attack.
Primer for the treatment of the reinforcing layer before applying the plaster. Its use is necessary to improve surface adhesion.
Facade plaster. Its choice and consumption depends on the chosen texture of the surface of the facade.

Preparing walls for insulation

The quality of thermal insulation work largely depends on the tightness of the foam boards to the wall surface.

In order to ensure tight contact of materials, it is necessary to carry out preparatory work.

Need to:

Clean the walls of flaking sections of old paint or plaster. You also need to remove dirt, dust, oil stains from the surface - all this reduces the adhesion of the adhesive mixture.
If there are colonies of mold, fungus, moss on the walls, they must be removed, and the surfaces affected by them should be treated with a bactericidal or fungicidal composition and allowed to dry.
Any bumps and protrusions of the walls must be knocked down. If there are cracks or potholes on the surface, they must be repaired with a conventional mortar or a special repair compound.

If, after checking the verticality or evenness of the walls with a level, deviations of more than 20 mm were found, it will be necessary to carry out leveling plastering of the facades. After that, the walls should dry for 4 weeks.
If in the future there will be any metal supporting structures on the walls (brackets, elements for fastening drains, etc.), they must be installed before the start of insulation work. In this case, all metal parts that go under a layer of insulation and plaster must be treated with an anti-corrosion compound.
The preparation of the walls ends with the application of a primer composition on them. To do this, you can use a roller or brush. Areas where the surface actively absorbs the primer. Needs to be processed again.

After the primer has dried, you can proceed with the installation of thermal insulation.

Technology of thermal insulation works

Penoplex installation is carried out in several stages, each of which has its own rules and features.

The start profile is set as follows:

The profile is attached to the wall according to the markup using dowels. The width of the profile must correspond to the thickness of the insulation boards. At the same time, it is very important that it fits as tightly as possible to the wall. If the fit is not tight enough, washers must be used.
Separate elements of the profile must be connected to each other using special connecting plates. The gap between adjacent elements should be 2-3 mm.

Preparation of the first composition should be carried out at a temperature not lower than +5 degrees. Glue needs to be diluted just enough to have time to use it before the mixture hardens. It is forbidden to dilute it with water again.

The glue is applied along the perimeter of the sheet with a strip, the width of which should be 8-10 cm. In the center, the glue is applied in slides (1-3 pieces). If the slab is laid on a slope or corner with a release, then glue is not applied to its protruding part. The thickness of the applied adhesive layer depends on the quality of the wall surface (its evenness), but should not be more than 20-25 mm. The area filled with the mixture should be approximately 40%. If the wall is even, then you can apply the mixture over the entire surface of the plate, using a notched trowel for this.
Next, the first row of plates is installed on the starting profile. The edge of the plate should fit snugly over the edge of the profile. If you find that there is a gap left, then not enough glue was applied.
Each installed plate must be firmly pressed to the surface and leveled without loosening the pressure. Spilled adhesive must be removed immediately.
When gluing the following plates, it is necessary to achieve full alignment of the side joint lamellas present on the plates. If the lamellas are cut off during fitting, then you need to achieve a minimum gap between the insulation elements.
Having pasted the next plate, it is necessary to check whether it is in the same plane with the already installed plates. To do this, use the rule with the level. While the glue has not yet set, it is possible to correct the position of the plate.
Further work is carried out similarly, in order, in the direction from bottom to top.
At the end of the installation, you need to pause for 3 days so that the glue finally hardens. After that, the elements are additionally fixed with fungal dowels, which are placed in the corners and in the center of the plate.

If the work is not done perfectly, then gaps may remain between the plates, which can be filled with wedges cut from the remnants of the foam.

Then the surface is finally sealed using Penoplex mounting foam.

If a break is provided for in the work, then the insulation must be closed from the sun, since when exposed to its rays, it begins to quickly decompose. But it is better to carry out the installation of a protective layer in a short time.

The device of a protective and reinforcing layer using a fiberglass mesh with a specific density of about 140-160 g/sq. m is carried out according to a certain algorithm.

The glue for creating the layer is the same as for sticking the plates. It is also bred in the same way, but the consistency can be made a little less thick.
Work begins with the corners of the building and slopes. To do this, they prepare grid strips 100 cm long and about 30 cm wide, bending them in half along the length, they get something like a corner. On sale there are special corners for reinforcing these areas. Their use will speed up and facilitate the work.
Strips of mortar about 10 cm wide and 2 mm thick are applied to both surfaces of the corner. The corner is installed and leveled, its side mesh sides are sunk into the solution using a spatula.
Next, reinforce the remaining sections of the facade. To do this, the mesh is cut into strips about 100 cm long.
Next, the cut strips are glued into the solution applied to the surface. Adjacent strips are glued with an overlap of 10 cm (both horizontally and vertically).
After the solution has dried, the primary grouting of the surface is carried out with a grater equipped with sandpaper.
Then a second leveling layer is applied. The total thickness of the reinforcing layer should be approximately 4 mm. At this stage, you need to try and give the surface maximum evenness, because it will serve as the basis for applying decorative plaster or facade paint.

If further painting of the facades is supposed, then the quality of the re-grouting should be almost perfect, since the paint will reveal all, even small, errors.

If it is necessary to insulate the facades of a wooden house with the help of Penoplex, we must not forget that the insulation is not able to pass air and moisture. Therefore, here it is necessary to exclude a tight fit of the insulation boards to the wood, using the ventilation gaps between the wall and the thermal insulation layer.

For a person who undertakes the construction of his own house for the first time and has not studied the “materiel” enough, the very fact that the foundation, it turns out, also needs thermal insulation, may seem strange. It would seem - why insulate a reinforced concrete tape if neither a basement nor a basement is supposed to be? If there is no direct contact with living rooms, are they located higher? Which is better to apply? Such a misunderstanding of the importance of the issue often leads to the fact that thermal insulation work on the foundation is not initially planned and not included in the estimate.

Meanwhile, such neglect of this stage of work entails a lot of negative consequences - a little lower we will talk about this. Moreover, the condition of the entire house as a whole directly depends on the strength of the foundation of the building and its durability. And a negligent owner, looking for savings in such matters, lays a "time bomb" under his possessions.

This publication will consider the insulation of the foundation with foam plastic technology, calculations, important nuances of implementation, up to step-by-step instructions. Read, get acquainted, immediately provide for one of the mandatory stages of construction. Well, if someone’s house already stands on an insulated strip foundation, it’s not too late to correct the situation.

Is it really necessary to insulate a reinforced concrete foundation?

So, for starters, it seems necessary to dispel doubts about the advisability of insulating a reinforced concrete foundation. And several reasons can be cited as justification.

It would be very naive to believe that the problem of thermal insulation of the ground floor premises is solved by insulating walls and floors. If the foundation in its recessed and basement parts remained "bare", then it, due to the huge heat capacity, turns into a powerful cold accumulator. And it will literally “pull on itself” the heat generated by the heating system. The consequences are clear: these are difficulties in providing comfortable living conditions, and unnecessary energy overruns. And with an insulated foundation, heating costs are very sensitively reduced.
If the foundation is not insulated, then the temperature of its upper buried part, above the freezing level, and even more so the basement, will always be strikingly different from that in the sole area (here it does not change much throughout the year). Such a temperature difference and the resulting difference in the linear expansion of the material create very significant internal stresses in the reinforced concrete foundation belt. And this, in turn, becomes a prerequisite for the appearance of cracks, accelerated aging of the structure, deformations and even gradual destruction. This means that it is necessary to take measures to eliminate such a “temperature gradient” - this will just help to make a layer of thermal insulation.

The eternal "enemy" is water, which penetrates into the pores of the material and leads to its erosion during freezing and thawing. Thermal insulation fights this too. First, most of the insulation materials used in this area of the building make a good waterproofing barrier on their own. Secondly, the thermal insulation layer brings the dew point out, namely to the insulation layer, and the foundation material no longer suffers so much from high humidity in combination with temperature changes. Of course, high-quality concrete, according to its characteristics, has a rather high frost resistance index (permissible number of freeze and thaw cycles). But this pledged reserve of its strength is still not worth spending thoughtlessly.
As a rule, the insulation of the foundation is carried out in conjunction with the creation of an insulated blind area around the perimeter of the house. This combination of vertical and horizontal thermal insulation will not allow the soil to freeze in the area of \u200b\u200bthe foundation tape. And this, in turn, means that the forces of frost heaving will not act on the foundation.

In the importance of waterproofing the buried part of the foundation, it is wrong, no one needs to be convinced. And the layer of insulation here plays another very prominent role. Firstly, it does not allow direct contact of wet soil with reinforced concrete tape. And secondly, it protects the waterproofing layer applied to the foundation from mechanical damage.

Pay attention to an important nuance. All the positive properties of the thermal insulation layer listed above will be possible only when it is located on the outside of the foundation tape. You should not leave it "for later", with the expectation of sticking the walls from the inside, "when the hands reach". Yes, perhaps this will somewhat improve the microclimate in the basement or basement. But in fact, the foundation still remains without any kind of protection. So - only on the outside!

Why is penoplex seen as the optimal material for insulating the foundation?

The variety of modern thermal insulation materials is quite wide. But not all of them are suitable for the specific conditions of foundation insulation.

It is understandable - the insulation, in fact, is buried in the ground, that is, it will be subjected to a very serious mechanical effect. In addition, it is constant contact with the soil, which, especially in the upper layers, is saturated with soil moisture, often containing very aggressive chemical compounds.

That is, the material must have sufficient rigidity and strength, minimal hygroscopicity, a high degree of inertness to chemically aggressive substances, and at the same time not lose its thermal insulation qualities throughout the entire service life. There is such a material - it is extruded polystyrene foam (EPS). One of the most famous Russian manufacturers of XPS is the Penoplex company. And its name, having slightly changed, has become a household name in our time - penoplex is often called any high-quality extruded polystyrene foam.

Nevertheless, let's look at Penoplex branded products. For individual construction, the company's product range offers four brands of insulation boards - "Comfort", "Foundation", "Wall" and "Pitched Roof". It is very convenient with the names - you can immediately see which parts of the building are mainly intended for insulation.

By the way, all of the listed brands have a sufficient degree of versatility. But still, Penoplex ® Foundation slabs are adapted to the maximum extent to the specific operating conditions mentioned above.

These plates are given increased rigidity and mechanical strength in compression and fracture. And the fact that they do not undergo special treatment to increase resistance to fire or ultraviolet radiation is absolutely nothing to worry about. It is clear that hidden by a layer of soil, they are completely protected from both fire and sunlight. At the same time, their thermal insulation qualities are no worse than those of slabs intended for walls, roofs, ceilings, etc.

The main characteristics of Penoplex ® Foundation are shown in the table below:

Name	Test method	Unit	Numerical indicators
Compressive strength at 10% linear deformation, not less than	GOST EN 826-2011	MPa (kgf/cm²; t/m²)	0,27
Static bending strength	GOST EN 826-2011	MPa (kgf/cm²; t/m²)	0,4
Density	GOST 17177-94	kg/m³	27 ÷ 35
Water absorption in 24 hours, no more	GOST 17177-94	% by volume	0.4
Maximum water absorption during the first month of operation (it will not become higher later)	GOST 17177-94	% by volume	0,5
Vapor permeability coefficient		mg/(m×h×Pa)	0,005
fire resistance category	F3-123	group	G4
Thermal conductivity coefficient at (25±5) °С	GOST 7076-99	W/(m×°С)	0,032
Operating temperature range	THAT	°C	-70 … +75
Standard sizes	Width	mm	600 (useful - 585)
	Length	mm	1200 (usable - 1185)
	Thickness	mm	50; 100
Estimated service life		years	at least 50
Approximate cost of one plate 50 mm		rub.	200

As you can see, the material is very light and quite durable. Almost complete water resistance gives it the function of additional waterproofing. The chemical structure is highly stable (unlike, for example, a close "relative" of foam plastic - ordinary white foam), and is completely unaffected by biological decomposition and damage.

You may be interested in information on how to do it yourself

The convenience of working with penoplex (as it will be called in the course of the article further, meaning "Penoplex ® Foundation") lies in the presence of mating edges along the perimeter of the plates. L-shaped grooves (quarters) when laying the material overlap the lines of joints, thereby making the thermal insulation coating continuous, without through cold bridges.

If necessary, the material is easily cut - cut with a hacksaw or even a sharp construction knife.

According to what scheme is the strip foundation insulated?

Approximate scheme for performing thermal insulation of the foundation with foam plastic

In order to move on and analyze all the nuances of the foundation insulation technology, first you need to understand the general scheme by which it will be produced. The scheme, of course, is given in some simplification, but still reflects all the main elements of the structure being created.

1 - soil at the construction site.

2 - sand (sand-gravel, sand-gravel, depending on the characteristics of the soil) cushion under the base of the foundation.

3 - shows a pipe of an annular drainage system, which is often provided along the perimeter of the foundation if it is being built on waterlogged or seasonally waterlogged soil.

4 - reinforced concrete foundation tape. (By the way, the foundation can also be prefabricated, made of reinforced concrete blocks, rubble stones, etc.)

5 - a mandatory outer layer of reliable waterproofing of the vertical walls of the foundation tape.

The best choice for self-insulation of the foundation (in terms of price-quality ratio) is Penoplex. In terms of performance, only polyurethane foam spraying is better than this material. A base without high-quality hydro- and thermal insulation is not a reliable support for a building due to the effects of frost heaving and groundwater, as well as temperature changes.

Reinforced concrete has a high thermal conductivity. Its periodic freezing gradually leads to destruction. Heat loss through the foundation is up to 20%.

Advantages:

reduction of heat loss through walls, saving heating costs;
protection of communications from exposure to low temperatures;
additional waterproofing, no mold, dampness in the basement;
reduction of soil heaving, the deformation of structures caused by it, extension of service life;
on the insulated base, the dew point is outside, which eliminates the appearance of condensate on the walls and communications from the difference between internal and external temperatures, which prevents dampening of concrete and failure of pipes;
increasing the level of soil freezing, which allows laying at a shallower depth;
in winter, the above-ground part is exposed to lower temperatures than the underground, which leads to the appearance of internal stress in concrete, thermal insulation compensates for the difference.

Penoplex insulation effectively copes with all these tasks. The technology allows you to independently mount it both on a new and on a long-established basis, the old one is previously dug in.

Characteristics Penoplex Foundation

Penoplex - a plate made of extruded polystyrene foam, an improved version of polystyrene. It has a porous structure with small cells (up to 0.3 mm) filled with air. Thickness - from 20 to 100 mm, dimensions - 600x1200 mm. At the ends there is a tongue-and-groove lock, which makes it easier to connect the sheets to each other.

Advantages:

easy to cut with a regular hacksaw;
simply mounted with your own hands;
has a low specific gravity;
very low level of thermal conductivity;
does not require additional waterproofing, moisture penetrates only into incised pores;
good soundproofing characteristics;
withstands from 50 freeze-thaw cycles;
not subject to rotting, development of fungi;
high degree of compressive strength - from 0.2 to 0.5 MPa;
operating temperature range - from -100 to +75°C.

You need to purchase XPS only from trusted manufacturers, as many small companies add components that eventually begin to release substances hazardous to human health. Penoplex is an officially recognized brand of expanded polystyrene. It is produced by the Russian company of the same name.

There are several varieties of this material. The name of each type indicates for which surfaces it is intended. You can insulate the base of the building with the help of Penoplex Foundation, Geo, Comfort. They differ from other types in the absence of flame retardants (additives that impart fire resistance) and increased density.

Flaws:

fire hazard (not suitable for baths at all), during combustion it can emit harmful gases;
damaged by rodents;
relatively high cost;
upon contact with some chemically aggressive compounds, it softens and melts.

List of substances that can damage Penoplex:

acetone, methyl ethyl ketone, other ketones;
gasoline, kerosene, diesel fuel;
formalin, formaldehyde;
coal tar, toluene, benzene, similar hydrocarbons;
ethers;
oil paints;
epoxy resin hardeners (polyesters).

Step-by-step instructions for thermal insulation of a strip foundation

Do-it-yourself vertical insulation technology:

1. After the poured foundation has dried, remove the formwork. Dig a trench along the perimeter to a width of 1 m. Its depth should coincide with the sole of the base of the building.

2. Clean the sides with a stiff bristle brush. Remove the sags with a grinder with a grinding wheel for concrete. It is not recommended to skip these operations, otherwise you will not achieve high-quality waterproofing and insulation. If defects are found, repair them with cement mortar.

3. Apply with a roller on the top and side parts several layers of waterproofing bituminous mastic (primer). In the corners it is more convenient to use a brush.

4. Paste over, starting from the sole, the smeared surfaces with roofing felt or welded roll material (such as TechnoNIKOL). To work, you need a gas burner. One person heats with a flame, the second one unwinds the roll and glues the heated fragment onto the base. The strips should overlap each other by 100 mm.

5. If possible, then according to the technology it is recommended to paste over with a second layer of waterproofing. The foundation will withstand any pressure of water, even floods.

6. Prepare a special adhesive for thermal insulation work according to the instructions. Instead, you can use water-soluble bituminous mastic (see the list of substances incompatible with Penoplex). On sale there is a special mastic.

7. Apply the adhesive pointwise with a notched trowel. Calculate the amount in such a way that the excess does not come from under the glued boards. Allow the glue to set, this will take about one minute.

8. Press the insulation firmly against the area covered with glue. It is recommended to glue in two layers so that the seams of the first are covered with sheets of the second. Start from the bottom, the thermal insulation layer must exactly follow the shape of the base.

9. In the upper above-ground part, according to the technology of insulation of the foundation with Penoplex, you can additionally use fungal anchors.

10. If there are gaps left, seal them with mounting foam, cut off the excess after drying.

11. Attach a reinforcing mesh on top and plaster. Sometimes, instead of a plaster layer, they are finished with a profiled membrane.

12. Fill the trench with soil.

Step-by-step instructions for insulating a slab foundation with Penoplex

1. Create markup according to the scheme. Mark the first corner, use a square and fishing line (rope) to set the position of the rest. At the same time, take into account that the base protrudes beyond the walls by at least 10 cm, and the pit is always 50-100 cm larger than the slab on all sides. This stock is needed for drainage and blind areas. Measure the distance between the diagonal corners to make sure that the discrepancy does not exceed 2-3 cm.

2. Remove the top fertile soil layer. Many people continue to use it.

3. Dig a pit. If the soil is dense, then a depth of 50 cm is sufficient, but if the soil is very weak, then it is removed completely. In this case, the depth can be more than 100 cm.

4. Level the bottom.

5. Pour sand (approximately 20 cm). Tamp, pour water or cement milk.

6. Lay the geotextile so that it completely covers the bottom and goes to the walls of the pit. According to the technology, a layer of geotextile is placed under the base itself and the blind area.

7. Pour crushed stone (also about 20 cm). Pour concrete M50 on top (up to 10 cm). It is needed so that the waterproofing material is not damaged by the sharp edges of the rubble.

8. Spread on a concreted slab with an overlap in two or three layers of a strip of roofing material or polyethylene film.

9. Insulate from above horizontally with Penoplex Foundation or GEO (up to 30 cm).

10. Install the formwork, tie the frame from the reinforcement, pour concrete.

11. After complete drying, clean the side surfaces with a brush. Remove the sags with a grinder with a grinding wheel for concrete. If there are small gaps, seal them with cement mortar.

12. Apply two layers of waterproofing bituminous mastic to the ends with a roller and brush. The upper part of the slab base is insulated during floor installation.

13. Glue roofing material or welded rolled waterproofing material with an overlap on the smeared planes, with a 100 mm approach in two layers.

14. Spread the adhesive pointwise with a notched trowel or bituminous mastic in a continuous layer with a brush.

15. Press the insulation firmly against the surface smeared with glue. Paste over all the side parts of the foundation, connecting the sheets with the help of grooves and ridges at the ends. Then create a second layer of Penoplex so that the seams of the first are closed. In the above-ground part, you can additionally use mushroom-shaped dowels.

16. Fill gaps with mounting foam. Cut off excess after drying.

17. It is also better to isolate the blind area with Penoplex. Fill the bottom with sand and gravel. Lay drainage pipes parallel to the walls. Pour another layer of sand on top. Then lay Penoplex horizontally, making sure that the boards fit snugly against the thermal insulation on the sides of the base. If you leave a gap, then cold will pass through it.

18. Finish the ends with plaster or profiled membrane.

19. Cover with the last layer of sand and gravel and pour concrete.

Effective insulation requires the installation of thermal insulation in a horizontal and vertical position. The horizontal layer is laid out in a continuous layer at the level of the sole of the base along the perimeter of the building to prevent freezing and heaving of the soil, creating cold bridges under the house. Often, insulation is laid directly under the blind area.

The most common mistakes:

Applying waterproofing to wet concrete. The plates will peel off along with the roofing material.
Glue, which includes substances softening polystyrene foam.
Use of glue instead of bituminous mastic.
The complete absence of coating waterproofing.
Use of materials that have been damaged as a result of improper storage.
Fixing Penoplex to the underground part of the foundation with fungal dowels, which are designed for mounting on walls. This violates the integrity of the waterproofing, and due to the pressure of the soil, a strong fixation to the side parts of the base of the building will be ensured, so additional fasteners in this part are not needed according to the scheme.
Lack of blind area.
Gap between horizontal and vertical layers.

Price

The final price of work per m2 consists of the necessary materials:

Bituminous mastic - from 65 rubles / kg, consumption - 1 kg / m2.
Built-up waterproofing TechnoNIKOL - from 135 rubles / m2.
Glue - from 24 rubles / kg, consumption - 6 kg / m2.
Penoplex Foundation, thickness 50 mm - from 1900 rubles / m2, when calculating, take into account that two layers are needed.
Reinforcing mesh - from 30 rubles / m2.
Plaster - from 10 rubles / kg, consumption - from 12 kg / m2.
Profiled membrane (instead of mesh and plaster) - from 85 rubles / m2.

If it is not possible to make thermal insulation yourself, then it is advisable to hire professional builders. Work on the insulation of the foundation with Penoplex will cost from 460 rubles / m2. The price includes the application of mastic, pasting with rolled material, installation of insulation, finishing (membrane, plaster).