Reliable insulation of the foundation with expanded polystyrene (foam). Slab foundation insulation technology Extruded polystyrene for foundation

Construction country house– this is the dream of many of us. But in order to ensure the necessary conditions For favorable living of the whole family in winter and summer, it is imperative to insulate the foundation of the house from the outside. Without thermal insulation, not only does the level of heat loss increase, but there is also a danger of destruction of the underground structures of the structure.

On a suburban area

Thanks to high-quality insulation of the foundation and plinth, heat is retained in the room and penetration is prevented groundwater, and also provides protection from low temperatures. In order to prevent exposure to aggressive environment on the foundation of the house, protective measures are carried out, and the most important of them is external thermal insulation.

Requirements for insulation

To obtain a high-quality result, it is not enough just to carry out all activities professionally.

Important factors are also the right choice Supplies and their high quality.

It is quite difficult to choose insulation that is optimally suited for a specific purpose, both in quality and financially. After all, today you can find many options for insulation of various price category and from different manufacturers.

Do-it-yourself installation of extruded polystyrene foam on a plinth

Therefore, when choosing, you should pay special attention to the following qualities of the material:

1. Low hygroscopicity. This parameter is very important, as it determines the degree of moisture absorption. At a high rate, the material will absorb moisture and as a result will collapse, which will lead to the destruction of the base itself.
2. High strength. The thermal insulator must withstand heavy loads of underground compressive forces. For example, the impact of soil, which increases in volume when frozen.
3. Low thermal conductivity. The thermal insulator must have a reduced thermal conductivity coefficient to ensure good thermal insulation.
4. Long service life. The thermal insulator should have approximately the same service life as the building, because replacing it is a rather labor-intensive process.

Taking into account all these requirements, you can choose the most suitable material for insulating the outside of your house with your own hands.

Coating waterproofing and penoplex

Selecting a thermal insulator

To insulate the foundation of a house from the outside, it is important to select a material whose properties are most suitable for the building, taking into account all its features and the climatic conditions of the area. Today, the following are especially popular among many consumers:

• expanded polystyrene;
• liquid polyurethane foam;
• extruded polystyrene foam.

Expanded polystyrene

It is an improved version of polystyrene and its derivatives and is a gas-filled material. Widely used in various branches of construction and industry.

Penoplex installation

The main advantages are:

1. Low degree of thermal conductivity. Allows you to keep the room warm. For example, a material 11 cm thick gives the same results as a two-meter brick wall.
2. Waterproof. Moisture absorption is about 6%, which allows the material to be used in conditions high humidity without fear of deformation.
3. Long service life. Withstands up to 60 cycles of operation in temperature conditions from -40 to +40 C.
4. Insensitivity to biological effects. The material is not exposed to microorganisms, mold and fungi.
5. Environmental friendliness. During production, substances that are harmless to human health and the environment are used, so expanded polystyrene is also used in the food industry.
6. A light weight. Thanks to it, the insulation of facades becomes labor-intensive and does not take much time.
7. Heat resistance. When ignited, fire-resistant types of polystyrene foam tend to self-extinguish.
8. Soundproofing properties. This is especially important for owners of houses and apartments in noisy areas. The use of 3 cm thick polystyrene foam sheets for insulation can reduce noise by 25 dB.
9. Vapor tightness. The indicator depends on the density and structure of the type of polystyrene foam. Varieties with low vapor permeability are similar in this indicator to certain types of wood: pine, oak.
10. Chemical resistance. The substance is not subject to the aggressive effects of ethers and alcohols, but is destroyed under the influence of solvents.
11. Resistance to mechanical stress. Mechanical strength during tension is approximately 20 MPa.
12. Relatively low price, which increases the availability of the material for many consumers.

Wiring diagram

So, polystyrene foam is an ideal option for use in for various purposes, especially for thermal insulation of foundations.

Liquid polyurethane foam

Liquid polyurethane foam is a polymer insulation material that is widely used to obtain a uniform insulating coating.

This is one of the few materials that are simultaneously a thermal insulation, vapor barrier and waterproofing layer. They allow you to significantly save money and labor costs when performing thermal insulation work.

In the context

The advantages of liquid polyurethane foam are:

1. Low degree of thermal conductivity. This allows you to significantly reduce heat loss.
2. Long service life. The service life is more than 30 years.
3. The ability to create a favorable microclimate in the room due to optimal thermal conductivity and sound insulation.
4. Considerable strength. Due to its good density and strength, the material is able to withstand large mechanical loads without losing its performance properties.
5. Absolute sealing, which is very important when performing any type of insulation work.

Liquid polyurethane foam

Thermal insulation of the foundation using liquid polymer can be carried out both from the inside and from the outside. For external use, additional protection from direct sunlight may be required.

Protection is carried out by applying liquid rubber or facade paint, which prevents loss of waterproofing properties and increases service life.

Extruded polystyrene foam

It is a relatively young type of polymer heat insulator and is produced by foaming raw materials during the extrusion process. Due to a number of advantages, the material has won the trust of many consumers and today is widely used in various fields construction.

Formwork for blind area

The advantages of the material are:

• low water permeability;
• low thermal conductivity;
• chemical resistance is not organic solvents;
• ability to withstand a wide range of temperature changes: from -50 to +75 C;
• long service life;
• a light weight.

Installation drawing

Extruded polystyrene foam is widely used for interior and external insulation buildings, roofs, is integral part sandwich panels, etc. One of the most common types is penoplex.

Insulating the foundation from the outside with penoplex is relevant and popular due to its excellent performance qualities. Such slabs have increased strength and can withstand enormous loads, providing excellent waterproofing and drainage of groundwater.

Do-it-yourself thermal insulation of the foundation with penoplex allows you to solve several problems related to the construction of the foundation and equipment of the basement.

Foundation thermal insulation

Usage modern methods thermal insulation has great value, especially in areas with harsh climatic conditions. This prevents a significant portion of heat loss and freezing of soils, which increase in volume, which leads to a rise in their level.

Foundation insulation with polystyrene foam

Insulating the foundation of a house from the outside with polystyrene foam is excellent option to improve the thermal insulation qualities of the base of the house and prevent freezing.

Expanded polystyrene is an improved type of foam. Its use is more profitable, and installation is easier.

The video describes in detail how to insulate the base of a residential building with your own hands.

The process works as follows:

1. Preparing the base. This stage can be carried out both during the construction of the building and after its completion. To do this, you need to dig out the foundation, clean it of soil, debris, rust and grease.
2. Selecting sheets. In this case, you need to pay attention to two factors: density and thickness. They mainly use sheets with fire retardant additives and a density of 35 kg/m3.
3. Waterproofing. This will prevent the influence of groundwater and its penetration through the insulator layer.
4. Fastening polystyrene foam sheets with contact adhesive. You can attach two layers, but so that the panels of the second layer cover the joints of the first.
5. Protection of insulation with a reinforcing mesh to avoid strong mechanical stress and the penetration of rodents. A layer of cement mortar can be applied to the protective mesh.
6. Providing drainage. This step is considered mandatory when constructing a building on wet soils.
7. Basement insulation. The base also needs to be insulated in the same way, followed by finishing. After the glue has dried, the panels are additionally secured with nails.
8. Soil insulation. The event involves isolating the surrounding land with a blind area insulated with polystyrene foam slabs.

Insulating the foundation and blind area can significantly increase the temperature in the structure and protect the foundation from destruction.

Insulation of the foundation with liquid polyurethane foam

Considered quite effective way, which reduces heat loss by 20–25%.

The main difference is the method of application using a special spray installation.

To do this, two liquid components are mixed with each other, forming a thick foam. When applied, it increases in volume and hardens, forming a protective seamless layer with excellent thermal insulation and waterproofing properties. Optimal thickness application is considered 60 mm.

Wooden building

The polyurethane foam layer can be applied at a temperature not lower than +5 C. Surface preparation involves cleaning from contaminants, and surface quality is an unimportant factor.

As the foam hardens, it changes color. When performing work, various problems may arise related to equipment and neglect of weather conditions.

For example, when applied under conditions subzero temperature Cracks may appear that need to be repaired in the future, otherwise water may accumulate in them and freeze. After polymerization, the polyurethane foam layer has low plasticity.

Foundation insulation using EPS

As a rule, not all insulation materials are suitable for thermal insulation of the base. To choose the right material for this purpose, you need to consider its service life: it must be as durable as the building itself.

Insulation with extruded polystyrene foam (EPS) is considered a more reliable method than, say, polystyrene foam, since this material more durable and has excellent performance characteristics.

Blind area with trays

For this purpose, you need to purchase heat insulation boards and suitable glue for attaching it. After this, a number of preparatory activities should be carried out:

1. Dig a trench around the foundation, digging into the ground.
2. Apply EPS to the freezing depth of the ground.
3. Clean the foundation from debris and dirt.
4. Apply a special primer in two layers, wait for it to dry and absorb into the concrete.
5. Provide waterproofing bitumen mastic.
6. Apply glue to the boards.

Attaching the slabs to the outer part of the foundation is allowed 1 minute after applying the glue. If the panels have a large area, you need to apply the glue in several strips using a comb spatula. If there are locks on the slabs, then a few days later the seams are sealed polyurethane foam, and the slabs themselves are additionally secured with dowel nails.

Two-story mansion

How to insulate the foundation of a wooden house

Many owners wooden houses They believe that to ensure favorable living conditions, it is enough to insulate the walls and floor. However, this is not so, because through wooden floor Serious heat losses can occur - up to 20%. Therefore, thermal insulation of the foundation is mandatory, especially if the house is located in an area with harsh weather conditions.

Insulating the foundation of a wooden house from the outside will not only create favorable conditions indoors, but also prevent adverse effect on him. For this purpose, polystyrene foam and its varieties, as well as expanded clay, are usually used.

Stone finishing

Insulation of the foundation of PPS or EPS

Expanded polystyrene has excellent consumer properties, such as low thermal conductivity and moisture absorption, resistance to negative influences weather conditions, affordable cost, ease of installation, etc.

These and other characteristics have made this material one of the most relevant and in high demand among many consumers.

To insulate only the above-ground part of the foundation or plinth, a fairly simple installation is required. PPS sheets are simply attached to the surface using glue or special fasteners.

After this, cladding or plastering is performed. However, you should know that installing insulation does not mean complete waterproofing, so it should be carried out separately to avoid groundwater from penetrating under the floor.

At the summer cottage

If you have a basement, you should insulate not only the above-ground part of the base, but also the part that is underground.

In this case, it is necessary to completely waterproof the walls. For this purpose, a trench is dug around the wooden house, then the foundation is cleared of soil and debris. Next, EPS panels are attached to the surface, after which the whole thing is backfilled and compacted.

The insulated base can additionally be finished with brick or other types of cladding that can withstand adverse weather conditions.

Foundation insulation with expanded clay

Often wooden house insulated from the outside with expanded clay. However, it has increased moisture absorption.

To avoid negative impacts To prevent this phenomenon, a trench is dug around the house and formwork with waterproofing is installed, after which the expanded clay itself is filled in.

Blind area

This method is no less effective, but requires special attention and the need to adhere to all installation rules.

DIY insulation video

The video explains in detail how to insulate the foundation of a house yourself.

Thermal insulation is necessary if the building has a basement or heated basement. It is also advisable to insulate an unheated room, especially if the height of the base is large enough. This will protect the walls and floors from freezing as much as possible. Insulating the foundation with foam plastic from the outside - affordable and effective method. But it has its own disadvantages and limitations that must be kept in mind when building a house.

There are three main reasons for carrying out thermal insulation measures. The first is reducing the building's heat losses and increasing the level of comfort. An insulated foundation allows you to reduce thermal energy losses and significantly save on heating costs. In addition, the floor in such a house will always be warm, even in severe winter.

The second reason is the fight against frost heaving. This phenomenon is typical for clay soils, which retain water well. In winter, moisture in the soil freezes and increases in size ( unique property water). In this case, increased pressure occurs on the foundations of the building, and part of the walls may rise. This will lead to cracks and deformations.

To prevent swelling, you need to exclude at least one of the factors of its occurrence: water or cold. Insulating the foundation with foam plastic allows you to maintain a positive temperature of the soil under the building and prevent the soil from freezing. This reduces the risk of damage.

The third reason lies in additional protection foundation structures from mechanical damage and other negative influences. Typically, thermal insulation is attached over a waterproofing layer. The insulation protects the moisture-resistant material and extends its service life, and, accordingly, the service life of the foundations.

Features of foam

Polystyrene foam or expanded polystyrene is a slab of small balls. This structure allows you to keep the material inside a large number of air. It is this that has the best insulating properties (except for inert gases). Air is used in all heat insulators, in the manufacture of windows, etc.

The thermal conductivity of polystyrene foam is comparable to that of mineral wool and extruded polystyrene foam. The thickness is assumed to be almost the same.

But when choosing the material in question, it is worth knowing that it is afraid of the simultaneous action of moisture and cold. Manufacturers may be silent about this point, but when the liquid between the balls freezes, the foam crumbles into separate particles. Without proper waterproofing, such insulation will not last long.

Advice! When insulating the foundation, it is safer to use extruded polystyrene foam. This is the closest relative of polystyrene foam. It costs more, but has greater strength and moisture resistance. Does not require additional waterproofing.

The advantages of polystyrene foam include:

• accessibility and affordable cost;
• ease of cutting and installation;
• good thermal insulation properties;
• safety for humans (except in cases of fire, therefore it is applied only outside the building).

Expanded polystyrene is not recommended for use if there is a risk of flooding. The reason is poor resistance to moisture. At the same time, the balls themselves do not absorb liquid and are not afraid of it, as many manufacturers indicate. But the connections between them are easily destroyed by the action of water and sub-zero temperatures.

Calculation of insulation thickness

Most manufacturers produce slabs with a thickness of 3 to 12 cm. Before insulating the foundation of a house with foam plastic, in each specific case a thermal engineering calculation is performed according to SP 50.13330.2012. This calculation takes into account the following initial data:

• type of structure (in our case, basement wall);
• outside air temperature;
• indoor temperature;
• operating mode of the building.

You can be guided by average values ​​for a specific climatic region. In most cases for middle zone In Russia, the thickness of the foam is 8-10 cm. In warmer climates, consumption can be reduced.

Advice! For accurate calculations, you can use special programs (for example, Teremok). In this case, it is possible to choose as the calculated design outer wall. But it’s worth checking the temperature and humidity indicators in the basement (they may differ from those indicated by default).

Preparatory work

Before insulating the foundation with foam plastic with your own hands, you need to prepare outer surface. To do this, follow the following procedure:

1. They dig out foundations to the depth of freezing.
2. Clean the structure from dirt, dust, and soil residues.
3. Prime the surface with a special compound. This layer will allow the wall and waterproofing to firmly adhere to each other. You can buy a primer (primer) in a store or make it yourself from a mixture of bitumen and fuel (diesel, gasoline). The mixture is prepared in a 1:1 ratio. The primer will take at least an hour to dry.
4. Next stage - . It will help protect the structure from moisture and premature destruction. It will also prevent basement flooding. Various materials are used as insulation. An inexpensive and popular method is. But it can be replaced with more modern and reliable types, for example, liquid rubber or. Of the latter, linocrom, hydroisol, technoNIKOL, etc. are often used. Another replacement option is a waterproofing profiled membrane (not to be confused with a smooth one for roof insulation).

Another important event that is included in the general complex of works on insulation and waterproofing of the foundation is laying drainage. It is mounted just below the base of the foundation at a distance of no more than 1 m from the structure. Drainage pipes with a diameter of 10-20 cm are laid with a slope in a layer of crushed stone 200 mm thick on each side. Extra layer bulk material wrapped in geofabric. This will avoid clogging the system.

Insulation technology

A rigid base is provided for the bottom row of slabs. This may be a protrusion of the foundation, provided at the stage of pouring or assembly, sand and gravel backfill(high quality compacted). Insulation is carried out along the perimeter of the building, without breaks. It is advisable to do this along the entire height of the foundation. The minimum layer of heat insulation should go 1 m into the ground (for central Russia).

The foam is glued to the waterproofing using glue. This can be bitumen-polymer mastic or polyurethane glue. The composition is applied both over the entire surface and pointwise (at least 5 attachment points per slab). When choosing an adhesive, it is important to carefully study the composition. It should not contain substances that can damage the foam. This will affect the service life of thermal insulation, waterproofing and the entire foundation. Hazardous substances include:

• acetone;
• petrol;
• toluene;
• other organic solvents.

It is advisable that the packaging indicate that the composition is suitable for the work being carried out.

Foam plastic slabs are usually joined together into a lock. To do this, the manufacturer provides recesses and ridges around the entire perimeter. It is recommended to additionally coat the seams with mastic or glue. This will prevent the formation of cold bridges and the penetration of liquid.

The layout of the slabs is done in a checkerboard pattern. It is important that the vertical seams are not too long.

Important! Mechanical fasteners (fungi) are not used to insulate the foundation. This may lead to damage to the waterproofing.

After fixing the polystyrene foam, it is necessary to backfill. In order to prevent contact of the foam with the ground and its displacement during ground movements, an additional layer is used roll waterproofing, geotextile fabric.

For backfilling, non-heaving materials are used: coarse or medium sand, sand and gravel mixture. The backfill is laid in layers with compaction. The thickness of one layer is 15-20 cm.

Insulated blind area

The logical continuation of the thermal insulation of the foundation will be the blind area. Its width is usually from 70 cm to 1 m. The blind area prevents moisture from entering the surface of the foundation and also protects it from the cold. The structure can also play the role of a pedestrian path. For this purpose, the covering is made of asphalt, concrete, paving stones, crushed stone, etc.

For insulation, you can use the same material as for vertical thermal insulation of the foundation. But it is better to choose extruded polystyrene foam. It has greater strength and will not wrinkle when people walk on the blind area.

The blind area pie in most cases looks like this:

• waterproofing;
• a compacted cushion of sand or crushed stone approximately 30 cm thick;
• Styrofoam;
• blind area material.

Proper foundation insulation is a whole range of measures, which includes thermal insulation, waterproofing, drainage and blind area. Individually, these elements do not provide effective protection against flooding and frost heaving.

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The foundation is the basis of any home, without it no one can be built real home. A properly designed and constructed foundation is one of mandatory conditions stability and durability of the entire building.

Even this reliable support is threatened by dangers - groundwater and soil freezing in winter, because of which the foundation of your house begins to collapse, and after it everything else risks collapsing. Insulating the foundation with polystyrene foam will effectively solve this problem and provide the house with many years of life.

Many professionals optimal material for insulating the foundation, as well as the basement and the entire plinth, extruded polystyrene foam is called - durable, resistant to moisture and has minimal thermal conductivity. Thanks to it, the structure will be reliably protected from dampness and frost, and the house will remain warm longer.

Not everyone clearly understands what polystyrene foam actually is. In general, this is nothing more than ordinary and well-known foam plastic used in everyday practice, mainly for packaging fragile items. This is a durable, lightweight, heat-saving, biodegradable and almost insoluble material obtained by filling styrene granules with gas and then heating them.

When exposed to temperature, the granules “swell” until they occupy the entire volume available to them and sinter together.

Extrusion or has a special manufacturing technology. For ordinary polystyrene foam, polystyrene granules are simply heated with water vapor, while to obtain EPS, several processes are used at once: the granules are mixed and heated, a foaming agent is introduced, and then extruded under high pressure, i.e. pushed through the molding hole.

This technology provides greater uniformity and, therefore, greater strength of EPS compared to foam plastic.

Pros and cons of EPS

Expanded polystyrene insulation at the lower level of the building confidently competes with the more familiar mineral wool. The latter loses its effectiveness when wet, so it is not advisable to use it underground. Expanded polystyrene for whole month direct contact with water (for example, with groundwater that becomes active in the spring) will absorb less than 1% of its total volume. In addition, this material does not rot and does not give in chemical influences and is able to withstand up to a thousand freezes without deforming or losing its properties.

The main positive quality of extruded polystyrene foam, which is extremely important for thermal insulation of foundations - low thermal conductivity - is explained by its unique closed-porous structure. Expanded polystyrene is, in fact, a cluster of closed cells filled with gas. Together they form a kind of air cushion, which does not let out heat from the inside and does not let in cold from the outside. That is, EPS ideally meets the requirements that high-quality insulation must meet.

The density of expanded polystyrene significantly exceeds the “ceiling” required to insulate the basement and basement (up to 35 kilograms per cubic meter).

Finally, the clear benefits for consumers are:

• light weight of the material;
• ease of cutting;
• ease of installation, ensured by connecting tenons and grooves along the edges of the slabs;
• resulting from the previous point, the ideal joining of the plates, so that the cold will not penetrate between them.

Expanded polystyrene also has its negative sides. The main one is the flammability of the material. Treatment with a protective compound will help solve this problem.

When and in what order to insulate?

The foundation is insulated with extruded polystyrene foam both during the construction process and when the house is already ready. You don’t need to be a professional to do everything yourself - EPS processing methods do not require any special skills.

Thermal insulation of the basement floor requires strict adherence a certain order actions:

• foundation preparation;
• installation of waterproofing material;
• laying insulation;
• installation of a protective layer;
• final finishing of the base;
• backfilling the trench;
• installation of a blind area.

Preparation and waterproofing

The preparatory process has its own nuances for each type of foundation. A “tape” of standard depth should be manually dug into a trench up to one meter wide and to the freezing depth. No technique is used in this case, so as not to accidentally “injure” the foundation. The surface is cleaned and leveled - the protrusions are chipped off and cracks are sealed with cement.

Waterproofing

Then a waterproofing layer is applied: bitumen mastic using a roller or liquid rubber from a spray bottle. It is important that the waterproofing material is applied in a continuous layer and does not contain organic solvents that have a destructive effect on EPS.

Even more effective protection The strip foundation will be provided by a combination of bitumen and rolled material. Ruberoid, fiberglass, etc. are applied to the mastic in a heated state with an overlap of up to 150 mm, the joints are coated with bitumen. In the same way, a slab foundation can be insulated from moisture.

If the foundation is on stilts

With a pile foundation, a combination of a waterproofing compound and a drainage system is required to protect against groundwater. The drainage is installed in the following sequence:

• a shallow trench is dug;
• the bottom of the trench is covered with crushed stone;
• geotextiles are laid on top of the crushed stone;
• pipes for drainage of water are laid at an angle from the house;
• on top of the pipes there is another layer of geotextile;
• is placed upper layer crushed stone

Installation of EPS

When the waterproofing is finished and the bitumen has finally cooled down, insulation of the foundation with polystyrene foam proceeds to the main stage. The thickness of the insulation is determined in accordance with the parameters of the foundation and the climatic characteristics of the region. For example, if the winter in the area where you live is harsh and long, it would be reasonable to lay the thermal insulation in two layers, five centimeters each.

Foundation insulation with extruded polystyrene foam

Expanded polystyrene sheets are available both corrugated and smooth. To ensure optimal adhesion to glue, the former are better suited. But if you nevertheless purchased smooth slabs, immediately before installation, treat them with a needle roller.

How to attach?

Fastening polystyrene foam below ground level requires the use of exclusively special glue that does not contain organic solvents. It is applied to the insulation with dotted strokes in the corners and in the center of the sheet. Then the insulation sheet should be firmly pressed against the foundation and held until the glue sets.

Under no circumstances should you fix the thermal insulation in the basement using dowels, as they will damage the moisture-resistant layer. Above ground, the sheets are attached to the wall with hardware three days after installation, when the glue has completely dried. Each sheet contains approximately five dowels, which are driven into holes drilled through the insulating material.

How to lay it?

EPS sheets should be laid from the corner of the house, checking the correct installation using a level. At the corners, it would be better to lay the material in two layers, with a meter extending in each direction from the corner. The slabs are mounted to each other using a connecting locking system at the edges. If there are gaps between the sheets, they are sealed with polyurethane foam sealant.

Thermal insulation protection

Thermal insulation must be protected from rodents and unexpected ground movements. There are two main protective technologies: using geotextiles and roofing felt or reinforced fiberglass mesh. The cost of the glue on which the mesh is attached is quite impressive, so it is permissible to use cement mortar instead.

Backfilling the trench

A trench dug around the perimeter of the house, after completion insulation works should be backfilled only when all materials are dry, including cladding ground floor.

This process occurs in several stages:

• the bottom of the trench is covered with a layer of sand up to 150 mm thick;
• the sand should be moistened, leveled and compacted well;
• Expanded clay or gravel is laid on top of the sand layer, the layer thickness is from 200 to 300 mm;
• the excavated soil is poured on top of the gravel cushion and compacted very carefully;
• The trench should not be completely buried; approximately 300 mm should remain to the ground level for the blind area.

Installation of blind area

Insulation of the foundation cannot be considered complete without the final installation of the blind area. The latter is a narrow path along the perimeter of the building, concreted or covered with asphalt. Its width varies depending on the extension of the roof, the minimum is 600 mm. The sloping surface protects the foundation from rain and melt water flows. In addition, the blind area insulates the soil along the house, which is especially important for regions with cold climates.

Insulation of the blind area

In frosty winters and clayey soil prone to uneven freezing, for additional insulation It is advisable to equip the blind area with slabs of extruded polystyrene foam. The strength and elasticity of this material fully corresponds to the functions assigned to the blind area.

Work order

To install the blind area, you must first pour sand into the residual trench in a layer approximately 100 mm thick, compact it and cover it with roofing felt. A formwork made of wooden beams is installed on top of the roofing felt, into which the insulation is tightly placed. This is followed by a layer of waterproofing film (in in this case it is permissible to use polyethylene), a layer of fiberglass mesh and, finally, concrete or asphalt.

Nuances of insulation for different types of foundation

With a slab foundation used on soft soil, insulation of the base is possible only during the construction process.

Installation is carried out in the following sequence:

• sheets thermal insulation material attached to the foundation with glue in a checkerboard pattern;
• a polyethylene film is laid (the overlap should be 150 mm), the joints are fastened with a special adhesive tape;
• a reinforcing metal frame is installed;
• concrete screed is poured.

When insulating pile foundation specially mounted outdoor wooden frame sheathed with polystyrene foam insulation with a thickness of at least five centimeters. The slabs are fixed with dowels, the joints are additionally reinforced with sealant. Appearance the design is not very aesthetically pleasing, so it involves finishing through decorative cladding.

Conclusion

High-quality thermal insulation of the foundation, especially in areas with an unfavorable climate, frequent precipitation, large amounts of groundwater and unstable soil, should be one of the first concerns of the homeowner. With properly selected materials and carefully executed installation, foundation insulation will not only help you save money on heating your home, but will also significantly increase the “shelf life” of your home.

The stability and durability of the entire house depends on the correct design and construction of the foundation. The installation of hydro and thermal insulation will protect the base from freezing, moisture and soil movements. Before starting work, it is necessary to decide which material will withstand difficult operating conditions with constant load. Extruded polystyrene foam (EPS), which has a low heat transfer coefficient, excellent moisture resistance and strength, will become optimal choice. Insulating the foundation of a house with extruded polystyrene foam will significantly reduce heat loss and protect the structure from destruction under the influence of water and frost.

Before starting thermal insulation work, there is a choice of what material to use on the ground floor and basement area. Most of the outside of the house is insulated with mineral wool, but when it comes into contact with moisture, it loses its properties, so it becomes ineffective underground. Expanded polystyrene, made by extrusion, has all the characteristics necessary for do-it-yourself insulation of the base of a building:

1. Low thermal conductivity (0.28-0.32 W/m*K) due to the structure of the material, consisting of closed, air-filled cells. It actively prevents heat transfer.
2. The slabs do not absorb moisture even in direct contact with it; water absorption is 0.6% of the volume of the material over a month.
3. Load-resistant, its compressive strength is 0.2-0.5 MPa.
4. The material does not lose its shape and characteristics up to 1000 freezing cycles.
5. Eps boards are easy to cut and mounted on walls, and have little weight. The presence of a tongue-and-groove joint along the edge facilitates joining of sheets and eliminates the formation of cold bridges.
6. The insulation is resistant to rotting and chemical attack.
7. EPPS sheets are produced with a density of 25-45 kg/m3. To insulate the foundation with your own hands, a material with a density of 30-35 kg/m3 is suitable.

Disadvantages of the material:

1. • high flammability; to enhance fire safety, you should choose slabs with the addition of fire retardants or apply a protective compound;
   • the material is used by rodents as a home.

Preparing the foundation for thermal insulation

You can insulate the foundation from the outside at the stage of building a house or when the building is already in use. The technology for doing the work yourself is simple; it does not require professional skills and tools.

1. A strip foundation is dug up to the very bottom, to the depth of soil freezing. The work is done manually so as not to damage the foundation. The trench width is 0.5-1 m, it should provide comfortable conditions doing the work.
2. The base is carefully cleaned of soil and concrete residues. During inspection, possible cracks and level differences are revealed. It is necessary to knock down particularly protruding areas, and cover cracks and depressions with cement mortar.

The correct trench for performing foundation insulation work

Base waterproofing

The application of the moisture-protective layer to the base must be carried out carefully, without the slightest omission. The material for waterproofing is selected depending on the type of structure. Isolation of shallow strip foundation performed using bitumen mastic. The composition is applied to the surface of the house with a roller, this will fill all the cracks. Waterproofing with liquid rubber is also used, which is applied from a sprayer. It is important to choose a mastic that does not contain organic solvents. These substances destroy polystyrene foam. A reliable protective barrier can be obtained by combining bitumen mastic and roll materials. First, mastic is applied, roofing felt is attached on top, and the joints of the strips are coated with bitumen.

Slab foundations require roll insulation. Modern weldable materials: fiberglass, roofing felt, rubitex heat up gas burner and are attached to the base treated with bitumen mastic as a primer. The insulation sheets are laid with an overlap of up to 15 cm. On top of the layer of rolled waterproofing, the foundation is insulated with polystyrene foam.

Roll waterproofing

The technology for protecting pile foundations from moisture requires careful application coating mastic or coloring composition. You can protect your walls and basement from water by making your own drainage. Its installation diagram is simple:

• crushed stone is poured onto the bottom of the trench;
• geotextile fabric is laid;
• drainage pipes are installed at an angle towards the well;
• the pipes are wrapped in geotextiles and covered with crushed stone.

Selection of expanded polystyrene

The quality of thermal insulation depends on the right choice material thickness. An insufficient value will produce minimal effect, and an excessive value will lead to unnecessary waste of funds. The effective thickness of slab insulation depends on the temperature of the region, parameters and base material. In cold regions, it is recommended to install two layers of 50 mm thick EPS on the outside of the strip foundation.

Sheets of extruded polystyrene foam are made with a smooth and corrugated surface. They do not differ in their characteristics, and gluing the sliding plate will be difficult. When purchasing such material, before installation, go over its surface with a needle roller or a wire brush. This will roughen the board and enhance adhesion to the adhesive.

Fastening technology

To insulate a shallow strip base, the insulation sheets are fastened with special glue. It should not contain organic solvents. The layer of bitumen mastic applied for waterproofing must cool before installing polystyrene foam. The adhesive composition is applied pointwise to the slab; 7-8 strokes will be required in the corners and in the middle. Pressing the material against the wall with your own hands, you need to hold it for a while to fix the glue.

Laying insulation outside starts from the corner of the house. To avoid distortions, the correct installation is checked building level. Each next row of slabs is fixed with an offset of half a sheet. Contributes to ease of installation lock system tongue and groove material. The remaining gaps between the plates are filled with foam. Even if the thermal insulation technology does not require laying EPS in two layers, it is better to provide double protection at the corners, extending 1 meter in each direction.

Fixation of extruded polystyrene foam requires only an adhesive composition. Hammering plastic dowels into the underground part is strictly prohibited, as it will break the tightness waterproofing coating. When insulating the basement floor, disc dowels are driven in 5 pieces per slab. To install the fastening, holes are drilled in the slabs and the wall of the house into which plastic dowels are driven. Work begins 3 days after gluing, when the composition has dried. Finishing the base is made of facing material.

Protection of the thermal insulation layer

The action of expanding soil and rodents can damage the insulation of the strip foundation. Fiberglass reinforcement will ensure the safety of the coating. An adhesive solution is applied to the outside of the insulation, into which the reinforcing mesh is embedded. Instead of expensive glue, you can use cement-sand mortar to attach the mesh. One of the ways to protect EPS is to install a layer of geotextile and roofing felt. These materials will prevent exposure to moisture and mechanical damage. To prevent freezing in unprotected areas, the external insulation scheme for a strip foundation should include simultaneous insulation of the blind area and the basement floor.

Backfilling the trench

Before digging a trench with your own hands , you need to wait for the plaster to dry. Sand is poured onto the bottom in a layer of 10-15 cm, it is leveled and compacted. A 20-30 cm cushion of gravel or expanded clay is placed on top. Then the excavated soil is backfilled with obligatory compaction of the layers every 30 cm. The trench is not buried flush with the site, 30-40 cm is left for installing the blind area.

Purpose and insulation of the blind area

A blind area is a concrete or asphalt strip around the perimeter of a house. It serves to protect the foundation from erosion by rain and melt water, improves the territory, and insulates the soil. The effectiveness of the last function of the blind area will be increased by placing a layer of extruded polystyrene foam under the concrete. Insulation of the blind area is necessary in the presence of clayey, heaving soil, characterized by uneven freezing and movement.

Eps boards high density specially designed for high loads, they are used on highways and airfields. This material will be the best option for constructing a blind area for a shallow foundation. The thickness of the plates used is 50 mm. The insulation technology includes the following stages:

• backfilling with sand or gravel in a 10 cm layer and compacting with wetting;
• laying roofing felt;
• installation of wooden formwork;
• EPS sheets are tightly placed in the formwork;
• the insulation layer is covered with polyethylene for waterproofing;
• reinforcing mesh is laid;
• concrete is poured.

The width of the blind area depends on the extension of the roof and the type of soil, its minimum size 60 cm, and the total thickness reaches 25-50 cm. The slope of the blind area is selected according to the type of material; for concrete it is 3-5º, and for stone – 5-10º. Installing the structure at an angle helps drain rainwater away from the house.

Nuances of insulation of various types of foundations

The thermal insulation scheme for a pile foundation involves covering the grillage with extruded polystyrene foam. The thickness of the plates used is at least 50 mm. When insulating the outside, a frame is pre-installed and sheathed with EPS sheets. The plates are secured with plastic dowels, and their joints are treated with polyurethane foam. Thermal insulation ends with decorative finishing.

A slab foundation is built on soft soil. Its thermal insulation is carried out on initial stage construction after applying roll protection against moisture. Sheets of extruded polystyrene foam are laid in a checkerboard pattern and are secured with an adhesive composition. The insulation is covered with a polyethylene film of 150-200 microns, which will protect the material from damage by the reinforcing frame. The film is laid with an overlap of 15 cm and taped with special tape. A concrete screed is poured onto the metal frame.

High-quality insulation of the foundation with polystyrene foam and finishing the base yourself will reduce heating costs and extend the life of the entire building structure.

Build highly effective thermal insulation of a stone house, perform insulation basement or the foundation of a building without the use of modern insulating materials is almost impossible. Of all the options available at cost and do-it-yourself, owners of new buildings and old houses most often choose the foundation insulation scheme with polystyrene foam. The main argument decision taken there was durability and high efficiency of polystyrene foam at relatively in a simple way installing it yourself. At the same time, the craftsmen, without going into the subtleties of technology, simply glue the base and foundation polystyrene foam board followed by sealing the insulation with a layer of thin plaster, as in the video:

Foundation insulation with extruded polystyrene foam - EPS

Expanded polystyrene itself is a type of foam that has undergone hot extrusion, resulting in a stronger and denser structure. EPPS has gained wild popularity as an insulation material due to a number of positive qualities:

• The highest ratio between price and insulation efficiency;
• The material is very light, a cubic meter weighs no more than 35 kg, which allows you to perform most insulation operations with your own hands without helpers;
• Expanded polystyrene does not rot and is not affected by microflora, it has high strength, which makes it possible to insulate the foundation with relatively large sheets.

Important! The most common mistake in using extruded polystyrene foam as foundation insulation is failure to apply additional system waterproofing.

The manufacturer states that the water absorption of EPS is about 0.8% per month of the sample being in water. In fact, the cells of expanded polystyrene are quite large and collect water vapor well, which means that the material, allowing diffusion moisture to pass through, will swell, thereby reducing the effectiveness of insulation to a minimum.

To install sheets of extruded polystyrene foam, a flat surface is required, without protrusions, seams and traces of formwork, which are always sufficient on foundation walls. However, when proper insulation foundation with expanded polystyrene, the technology of EPS stickers allows for thermal insulation much more efficiently and cheaper than using backfill methods, installing blocks of foam glass, foam concrete, polyurethane foam.

Effective insulation of the foundation with polystyrene foam

To insulate the foundation of a small private house, polystyrene foam in the form of small sheets of 60x100 cm, 30 mm thick, is best suited. This size of material allows you to work with a foundation with a height of 120 cm. They are simpler and more convenient to use. There are groove elements at the long ends of the sheet, which make it possible to obtain a “blind” joint without losing the thermal insulation properties of the joint.

Each sheet has inside, which is adjacent to the foundation, longitudinal grooves measuring 5x3 mm. If the extruded polystyrene foam sheet is installed correctly, the resulting water condensation will flow through the grooves into the lower part of the insulation system and be removed by drainage. Dried soil increases the effectiveness of foundation thermal insulation.

Methods of fastening extruded polystyrene foam

All methods and recipes for foundation insulation using sheets of extruded polystyrene foam can be divided into two main groups:

• The classic scheme for installing the material on the insulated surface using glue or adhesives;
• Easier and cheaper fastening of EPS using dowels.

The latter option is most often used for cladding facades; dowels provide strong fastening of extruded polystyrene foam boards to any surface. Most often, the facade, walls, and basement of the building are insulated in this way, and often, in order not to change the method of fastening, sheet insulation is installed with polystyrene foam and concrete blocks foundation. It is believed that fastening the sheets in one way on the base and on the foundation avoids the destruction of polystyrene foam boards due to temperature changes.

This method can only be used if concrete walls foundations do not have waterproofing or are covered with a fresh, undried layer of mastic coating, liquid rubber or a similar composition. It is clear that it can be installed over film or roll waterproofing only as a last resort, and only with obligatory coating of the dowel installation sites. Otherwise, pinpoint tears in the waterproofing film will lead to soaking and failure of the entire foundation insulation system.

Insulation by gluing polystyrene foam onto foundation concrete

Gluing insulation boards onto a concrete foundation base with your own hands is actually no more difficult than using dowels. All technological process very similar to sticking facing tiles, with the only difference that when installing a heat insulator it is necessary to achieve the tightest possible joints of individual sheets.

Insulation is carried out in three stages:

1. Carefully clean and level concrete surface foundation using a grinder and cutting wheels for stone, pass with a brush with metal bristles and blow air on the walls;
2. We coat the walls with liquid waterproofing composition, and you can install insulation boards. If waterproofing is carried out in a double layer, for example, by coating with bitumen mastic and knurling roll material, it is best to use a special glue that allows you to get good adhesion to polystyrene foam without dissolving the insulation;
3. The laid polystyrene foam is covered with a reinforcing mesh and plastered with a waterproof compound.

Advice! In the professional version of insulation, the laid layer of thermal insulation must be covered with film waterproofing, a thin steel mesh, a layer of geotextile and covered with grated clay.

Popular adhesive compositions for polystyrene foam insulation

In the professional version, bitumen-rubber or silicone adhesive mastic with the addition of rubber and special substances that enhance adhesion is most often used. It is enough to open a jar of the composition, apply it to the foundation, lay a sheet of extruded polystyrene foam and carefully press the slab to the concrete surface. The mass consumption is in the range of 1.5 kg/m2.

After about 10 hours, the installed insulation must be treated over the surface of the glued heat insulator with another layer of mastic, and dense polyethylene film and geotextiles must be laid. Thus, you get a “warm” cake that is not afraid of moisture, open water, temperature changes and even mechanical contacts with stones or gravel. To avoid damage to the insulation by rodents, before backfilling with soil, you can lay steel mesh or pour a layer of foam glass granules.

In addition to bitumen-rubber mastic, slabs can be strengthened using polyurethane foam, as in the video:

For work, use frost-resistant foam options that do not have secondary expansion due to the deep dissolution of the foaming agent in the polyurethane mass. Otherwise, rising layers of foam can distort and lift the edges of the slabs and expose the joints. One of the most commonly used foam for gluing insulation boards is Ceresit ST84 foam.

For direct laying of extruded polystyrene foam on a concrete surface the best option there will be a mixture of “SK 106P” “Aqualit” or “Ceresit ST85” or “ST83”. Both options are diluted with water and have a relatively short hardening period, so they are prepared adhesive mass immediately before laying the insulation.

Insulating the foundation of the blind area with polystyrene foam

Insulation of the foundation is unthinkable without additional measures for thermal insulation of the blind areas of the walls. About 30% of the heat from the concrete base of the foundation system is lost in the near-surface layers of the soil. Installing even a relatively thin layer of extruded material under a concrete base will reduce the depth of soil freezing by 15-20%. Extruded polystyrene foam is best suited for these purposes due to the high strength and elasticity of the sheets.

The blind area is made in the form of a wide concrete strip, 8-10 cm thick, with reinforcement cage. Most often, the function of the foundation blind area is protection from moisture and compensation for heaving of the soil under the walls.

The easiest way to do the insulation yourself is at the stage of building the blind area. To do this, you will need to dig a mini-pit the width of the blind area, to a depth of at least 30 cm. A thick waterproofing film will need to be laid at the bottom of the pit, which will drain water from under the blind area to the drainage area. Next, a 5-7 cm layer of sand and crushed stone is poured, geotextiles are laid and sand is re-filled. Before laying the insulation, the base is carefully compacted and leveled.

On next stage a layer of extruded polystyrene foam is laid out. Two or three layers of 30 mm sheet are best suited, depending on the required insulation power. Next, a separating membrane, reinforcement and formwork are laid to form a concrete layer of the blind area. The outer edge of the foundation blind area should overlap the edges of the insulation by at least 10 cm.

Conclusion

Today, foundation insulation using foam materials is the most effective and inexpensive compared to using silicate blocks, filling with expanded clay, laying aerated concrete slabs. The material of expanded polystyrene boards is calculated for cyclic strength when the temperature changes “winter-summer” for 80 years, therefore, if the installation technology is followed, the service life of the foundation insulation will be more than sufficient.

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