Do I need to insulate the foundation of the house from the outside with foam. Features of warming the basement of the foundation from the outside with foam plastic with your own hands. Insulation of the slab foundation with Penoplex

Before the invention of modern heaters, the foundations of private and multi-storey buildings were insulated in the old fashioned way, and most often the function of warming the base was performed by heating pipes that ran through the basement. That is, energy resources were wastefully spent, and heat was supplied to apartments and houses with great losses. With the advent of penoplex and other effective heat insulators, the situation has changed radically - do-it-yourself insulation of the foundation with penoplex gives a powerful economic effect, and the heat generated by the heating system at home is not wasted (the total savings while maintaining heat reaches 20%). In addition, foam insulation improves the moisture resistance of the base and walls of the building by an order of magnitude, and this increases the service life of concrete and brick structures of the house.

What is penoplex and why is it better than analogues

Traditional mineral insulation, rags went into the shadows after the appearance of extruded polystyrene foam on the construction market, even despite its high cost. Penoplex is not one material with certain properties, but a line of heaters, the distinguishing characteristic of which is the formation of a heat-insulating layer by foaming the original substance at high temperatures. In order for expanded polystyrene to start foaming, a gas mixture of carbon dioxide and freon (CFH 3 and others, CO 2) is added to it. The result of the interaction is a high-strength and dense substance, which has a uniformly distributed structure with granules Ø 0.1-0.2 mm in the composition. Expanded polystyrene is produced in plates of different sizes and dimensions.

Speaking of "penoplex", builders mean insulation, but in fact it is a branded Russian trademark of a company that produces extruded polystyrene foam for construction needs - this is insulation of the basement and other surfaces and structures of buildings, and thermal insulation of communication pipes, and protection from road frost coatings. Each brand of PPU is endowed with its own unique characteristics, optimally suited to the place of application of the insulation. So, the thermal insulation of the foundation from the outside with foam is carried out mainly by the brands Penoplex Foundation, Penoplex Comfort or Penoplex 45.

The advantages of this substance are obvious:

1. The minimum coefficient of thermal conductivity among analogues: λ = 0.03-0.032 W / (m × K). In practice, this means that polystyrene foam boards are used in much smaller thicknesses than conventional ones;
2. High compressive strength - 27000 kg / m 2;
3. Low coefficient of moisture permeability. If you keep such a plate in water for a month, then it will be saturated with moisture only by 0.6%. This indicator is very important, since the basement and foundation of the house are constantly in an environment with high humidity, being affected by precipitation and groundwater;
4. Extruded polystyrene foam can be operated in the temperature range -50 0 С/+75 0 С;
5. The small mass of the plates makes the installation of the insulation simple and quick, while it is practically not loaded with additional weight of the material, therefore, the insulation of the foundation with foam plastic is considered the most effective and least expensive;
6. PPU is not infected with fungi, does not decompose under the influence of moisture and aggressive external environment, is non-toxic and is recommended for use in residential and sanitary construction;
7. The ease and speed of mounting the plates is ensured not only by their low weight, but also by the presence of the "groove-thorn" system. Also, the material is easily amenable to any mechanical processing. Including manual;
8. The guaranteed service life declared by the manufacturers is at least 50 years.

Thermal insulation of the basement or foundation from the outside with foam plastic is the maximum duration of operation of the building material of the base plus fire safety according to group G4. This means that the material can catch fire, but given its constant presence in the ground without air access, plus the protection of the insulation layers with plaster, this is almost impossible. The dimensions of the expanded polystyrene plates are 600 x 1200 mm, the standard plate thickness is from 20 to 100 mm (in steps: 20 mm, 30 mm, 40 mm, 50 mm, 60 mm, 80 mm, 100 mm).

Which is better - external or internal insulation of the foundation

When insulating your house, in particular, the foundation, you should first of all calculate the thickness of the material and its properties for the correct choice of the brand of insulation, and you can make fairly accurate calculations on your own. The formula looks like this:

R \u003d h 1 / λ 1 + h 2 / λ 2;

1. R is the resistance to heat transfer in the region;
2. h 1 - the thickness of the walls of the base, mm;
3. λ 1 - thermal conductivity of the base building material;
4. h 2 - the thickness of the expanded polystyrene plate;
5. λ 2 - .

Example: when insulating a reinforced concrete foundation with characteristics λ = 1.69 W / m K and a wall thickness of 400 mm, the calculations will look like this:

1. 3.2 \u003d 0.4 / 1.69 + H 2 / 0.032;
2. 3.2 \u003d 0.24 + H 2 / 0.032;
3. 2.96 = H 2 / 0.032;
4. H 2 \u003d 0.0947 m, or ≈95 mm.

Result: With a foundation wall thickness of 400 mm, it is necessary to purchase foam plastic slabs 100 mm thick. When calculating, rounding should be done up, providing a margin.

In order to prevent the appearance of "cold bridges", "dew points", and to bury all the cracks, cracks and joints, it is recommended to fix the outer foam in two layers in a checkerboard pattern. That is, with an estimated thickness of the heat insulator of 100 mm, two layers of plates 50 mm thick can be used. The total number of plates is easy to calculate: in one package - 8 units.

Thermal insulation technology

When insulating the foundation with foam plastic, the technology must be strictly observed, taking into account the cost of the material. - a very technological material. If the foundation tape is insulated from the inside to the outside, then the installation sequence will be as follows:

1. Foundation;
2. waterproofing layer;
3. A layer of foam boards;
4. A layer of cement-based plaster;
5. Ground pillow;
6. Again, a layer of foam boards - under the blind area;
7. The blind area itself.

When warming from the bottom up, the following sequence is used:

1. sand cushion;
2. A layer of foam boards;
3. Foundation;
4. waterproofing layer;
5. Subfloor concrete screed;
6. A layer of waterproofing along the end of the foundation wall;
7. A layer of foam slabs along the end of a part of the foundation slab. The slabs are laid from the beginning of the sand cushion and above the level of the soil surface by 0.4-0.5 m;
8. A layer of foam boards under the blind area;
9. The blind area itself.

How to insulate the foundation with polystyrene foam

The first step is earthwork with the foundation. An option is being considered with an already built house and insulation of the finished foundation. A foundation is dug in along the perimeter to the full depth - it is necessary to make a trench up to 1.5 m wide parallel to the base. If the foundation is laid higher, then the insulation is still laid to the freezing depth, that is, below the base.

Important: extruded polystyrene foam (penoplex) should not come into contact with acetone and its derivatives, as well as with benzene and alcohol-based solutions.

In parallel with the trenching, the foundation is drained - for this, drainage pipes are laid along the perimeter of the building at a distance of up to 0.6 m from the base. For them, a separate trench is dug with a crushed stone-sand cushion at the bottom with a layer of up to 10 cm. The last layer in the cushion will be geotextile, on which drainage pipes are laid. Pipe slope - 20 mm per 1 meter. From above, the pipes are covered with the same pillow and wrapped in geotextiles. Pipes are discharged to a local storm drain.

The walls of the base are aligned using the following technology:

1. Beacons (perforated ribbed metal corner), on which the insulation will be mounted, are attached in increments of up to 1.5 m from each other. Height for beacons - from the lower surface of the base and 0.5 m above the ground;
2. The solution is prepared in a ratio of 4: 1 (sand - cement) to a thick state, is thrown onto the entire surface of the walls between the lighthouses, leveled with the rule;
3. After hardening of the draft layer, the last layer is applied for general leveling of the surface.

The next layer - waterproofing, should consist of two layers. These are bitumen and TechnoNIKOL plates. Bitumen is applied with a brush or roller in a layer up to 5 mm over the entire surface. After it dries, the TechnoNIKOL plates are glued from the bottom up, with the rear side heated by a gas burner. The plates must be overlapped, with an overlap of 10 cm, the joints are smeared with bitumen.

The first and second layers of penoplex are fixed vertically pointwise, in the direction from the bottom up, using acrylic glue, or inorganic-based adhesives. All plates are connected by the “groove-thorn” system, the joints are filled with glue or construction foam.

Plastering a heat insulator performs two tasks - protecting the walls and leveling them. On top of the plaster, a metal or fiberglass reinforcing mesh is attached, and it is also plastered with a thin layer. After the plaster has hardened, the trench is covered with soil.

Backfilling with soil is the last step in warming the base of the house. First, a pillow is made of sand and small gravel, followed by ramming at a depth of 0.3-0.4 m from the surface of the covered soil. Then any waterproofing agent (polyethylene, roofing felt) is laid on the sand, and foam plastic is laid on top. Joints and seams (both roofing material and foam plastic) are coated with bitumen or acrylic glue.

The blind area is made in the form of an inclined cement screed - to drain rain and melt water. The foundation can be finished with natural or artificial stone, ceramic tiles, siding or lining. The quality of foundation protection will be much higher if certified materials are used and the technology of all processes is followed. With the proper arrangement of the foundation with insulation, you can completely forget about repairing the foundation.

We continue our series of articles on the thermal insulation of the base of the house. Today we’ll talk about the insulation of the foundation with Penoplex with our own hands. Why Penoplex? How much will such thermal insulation work cost, and finally, how to carry out the entire installation yourself?

The material that is designed to insulate the base of the house has to perform functions in conditions that, as they say: "You won't wish it on your enemy." It will be surrounded by:

• Soil that may contain construction waste;
• groundwater;
• And also, it will experience the physical and mechanical load of the weight of the soil.

Already at this stage, it is clear that the material must not only be heat-insulating, but also have sufficient density and hydrophobicity.

Why Penoplex?

Penoplex or, to be more correct - Penoplex is a Russian brand for the production of polystyrene foam insulation (high-density foam). For the sake of justice, it is worth mentioning other brands, for example:

• Technoplex;
• URSA;
• Primaplex.

However, in the domestic space, the word "Penoplex" has become an eponym - the case when a proper name becomes a household name. And, in fact, now the name of this brand is applied to many types of polystyrene. However, for the sake of justice, in this article we will focus on Penoplex insulation in the classical sense of the word. Why is this material so good?

By the way, in one of the articles we compared two grades of polystyrene:

Material characteristics

Under this brand, several types of polystyrene are produced, we are interested in Penoplex Foundation insulation. These are plates measuring 1200 by 600 mm. They have different thicknesses from 20 to 100 mm. We highlight 3 features of this material in particular:

• - 0.030 W/(m×°K);
• Compressive strength (density) - 0.27 (2.7; 27) MPa (kgf/cm2; t/m2);
• Water absorption for 28 days - 0.5% by volume.

The table below shows more complete characteristics of Penoplex.

Simply put, the material has sufficient density to withstand the mechanical load of the soil, practically does not absorb moisture and retains heat well. However, various characteristics of the thickness of the insulation make you think, what exactly should the insulation be for my situation?

Minuses

Unfortunately, it didn't work without them.

Penoplex is more expensive compared to analogues. But, the high popularity of this material, despite the price, is a clear proof of its good performance. For the foundation, this is especially important. If, after backfilling, the insulation is damaged, the savings on the material will come out “sideways”.

Rodents spoil Penoplex, however, in the foundation it will be protected by soil.

It is destroyed upon contact with alcohol-containing solutions, so you need to take this moment into account when choosing waterproofing.

Required thickness

The thickness of the insulation depends on two factors:

• The region in which the insulation of the foundation of the house is carried out;
• The thickness of the concrete layer of the foundation walls.

For each region, building codes establish minimum indicators of thermal resistance - the ability of the building envelope to prevent heat from escaping from the premises. This indicator can be viewed in the SNIP dated February 23, 2003 "Thermal protection of buildings". The diagram below shows the indicators for the main regions.

In addition, we will need indicators of the thermal conductivity of the material from which the foundation is made and the same indicator of Penoplex. That is, in fact, you first need to figure out what the thermal resistance should be, and then how to get it.

Let's take for an approximate calculation the insulation of the foundation with Penoplex in Surgut. The required indicator for walls is 4.03.

We take for example a wall thickness of 550 mm. The thermal conductivity of concrete is 1.69.

0.550 m / 1.69 \u003d 0.2958 - as you can see, out of the required 4.03, only a minuscule amount of concrete is given.

Now, this amount must be subtracted from the total thermal resistance.

4.03-0.2958 \u003d 3.7342 this is the minimum indicator you need to achieve with the help of a heater. How thick should it be? The ability of Penoplex to conduct heat is 0.032.

We multiply 3.7342 by 0.032 and we get the thickness figure we need in meters, namely: 0.119 mm, we round it up and we need a Penoplepex Foundation with a thickness of 120 mm.

The cost of insulation

How much will it cost to insulate walls with this material?

If the house has a perimeter of 42 meters, and the depth of the foundation is 1 meter, then 42 squares need to be insulated.

Sheets with a thickness of 120 mm do not exist. But, there is Penoplex Foundation 100 mm and 20. You will have to insulate in 2 layers. A sheet 100 mm thick costs approximately 375 rubles and has an area of ​​0.72 m3. A sheet 20 mm thick costs about 70 rubles. In total, we need 59 sheets of each type. Weaving will cost us 22,000 rubles and the second layer 4,200, a total of 26,000 rubles for insulation.

If you add a few cylinders of glue-foam, then you can definitely meet 30,000.

Technology

How to carry out the insulation of the foundation with Penoplex? You need to start with the situation in which the installation is carried out:

• If you are just building a house, most likely its foundation is free from soil and nothing needs to be done first;
• If we are talking about an already arranged foundation, you must first free it from the ground. To clear a surface and only after that to carry out warming.

Also, it is worth noting that when insulating the foundation of a house, three components are insulated from the outside:

• blind area;
• Horizontal insulation on the pillow of the future foundation (carried out only during construction);
• Vertical installation of plates on the plinth.

We talked about how to make an insulated blind area cake separately, so here we will write in more detail only the last of these three points.

Preparing the workplace

If you need to insulate the foundation outside the already built house, you will have to dig it out. To do this with:

• own shovel,
• special equipment,

A trench is being dug around the entire perimeter of the building. The depth of the trench should be equal to the depth of the foundation. The width should be such that you can work comfortably. Please note that when you fix the foam to the foundation, the width of the trench will narrow, in our example by as much as 120 mm.

After that, you need to let the foundation dry, then the insulation will be valid. This takes at least 2 weeks. By the way, this nuance imposes some restrictions on the time of year in which work can be carried out. In the fall, the dug trench can fill with sedimentary water. Inspect the foundation and evaluate its condition. Plaster large irregularities, if any.

Waterproofing

We talked about this important step for the foundation separately, it’s only worth repeating here that waterproofing is mandatory for the foundation of a house with a basement. If there is no basement, perhaps Penoplex itself can handle it, because it repels moisture. If you use waterproofing, choose a composition that does not contain alcohol so that it does not corrode the insulation.

Mounting plates

Although you can find examples of penoplex being attached to dowels, this approach is considered unacceptable. Nails break the waterproofing layer, and even the insulation itself, which, unlike the “wet” facade, will not be particularly protected. You need to fasten the material to the glue-foam or other adhesive for fastening.

The fixing of the plates starts from the bottom row. With the help of the level, you need to mark the strip of the upper edge of the plate. The lower part of the plates is cut so that the upper edge always goes along the level.

If, as in our example, the installation from the outside with foam plastic occurs in 2 layers, the second layer must be fixed only after the first is completely fixed (solidified), usually not less than 2 hours later. That is, at first the entire foundation tape is covered with the first layer, then the second. Sheets are stacked in a checkerboard pattern, without joining seams.

After the insulation is covered with a membrane for additional protection against moisture and mechanical damage.

By the way, external insulation is considered the most effective.

Finally, a video: how to insulate the foundation of a house with Penoplex.

Insulation is an important part of any construction. It is necessary to isolate all external parts of the building from heat loss: walls, roof, basement and foundation. Insulation of the base of the building not only limits heat loss, but also prevents frost heaving of the soil. How is the insulation of a monolithic foundation performed? And what are the features of installing insulation on the wall and floor

Foundation insulation

Insulation of the foundation is necessary in those parts that are located in the zone of soil freezing. The basement and the top of the foundation wall are covered with insulation. In addition, heat-insulating plates are laid under the outer blind area around buildings. These measures help to protect the ground and walls from freezing and therefore avoid the earth around the house.

Different foundation designs have different ways of insulation. Tape deep - insulate only vertical walls near the surface of the earth, tape shallow - walls and soles. The pile foundation rests on non-freezing soil, therefore only the side surfaces of the piles are insulated.

Insulation of a monolithic slab of the foundation base is carried out from the sides and from below. This is necessary due to the location of the plate in the zone of soil freezing. The monolithic slab foundation is a shallow structure. The depth of its occurrence rarely exceeds 50 cm. Therefore, the entire plate is located in the zone of freezing soil and requires high-quality insulation. What materials are used to insulate the foundation slab?

Foundation insulation material: foam

The foundation insulation is subject to increased requirements for moisture and water resistance. It is in contact with moist soil, therefore, in addition to insulation, it must prevent moisture from penetrating into the walls of the house. In addition, the foundation insulation must withstand compressive loads.

The ideal material for foundation insulation is extruded polystyrene foam. The trade name of the material is penoplex. It has a closed cell structure, due to which water and moisture do not penetrate into the material and do not form its destruction. Fluctuations in temperature around zero create a variable state of "liquid-ice". When moisture is absorbed, the insulation cracks (as a result of freezing and expansion of water in the pores of the material). Therefore, ordinary expanded polystyrene (polystyrene) is not used in foundation insulation. You can use only moisture-resistant types of insulation: PPU or foam.

In addition to resistance to the penetration of moisture and steam, foam foam insulation can withstand significant compressive loads. Its price is higher than ordinary polystyrene. But it pays off with durability.

How to insulate: inside or outside?

How to properly insulate the foundation with foam plastic - from the outside or from the inside? Theoretical calculations show that the location of the insulation on the outside protects the wall and the slab from freezing. The location of the insulation inside the wall does not protect the wall and the slab, but it improves the microclimate in the room. This means that external insulation is the best option for any building surfaces.

However, it is not always possible to perform insulation from the outside. So for the foundation, external insulation is possible only at the construction stage. After isolating the base from heat loss is possible only from the inside.

Warming the foundation slab from the inside gives a noticeable positive result: the house becomes warmer and drier. At the same time, the plate itself continues to freeze in the winter season, so its durability remains small.

If the slab was insulated during construction, then the foundation does not freeze through and bears the load of the built house for a long time. How to insulate a slab foundation from the outside?

Foam insulation at the construction stage

Insulation at the construction stage involves laying insulation on the ground before pouring concrete. We list the sequence of actions for insulation during construction:

• To exclude uneven pressure of the foundation on the ground, part of the soil is removed and gravel and then sand backfill are made. A layer of sand is shed with water and carefully rammed.
• After that, a layer of waterproofing and insulation boards are laid.
• Reinforcing rods are placed on top of the insulating material and concrete is poured. At the same time, the reinforcement rods are placed in two rows, the bottom row is supported by plastic beacons (so that after pouring the reinforcement is inside the concrete).

In this way, a light, strong and warm foundation is obtained, on which the walls of the building can be erected in a month.

swedish foundation

The foundation, insulated from below with polystyrene plates and equipped with warm pipes, is called Swedish. The abbreviated abbreviation for the foundation sounds like "USHP" or Insulated Swedish Plate.

The thickness of the base plate can vary from 10 to 30 cm (depending on the type of soil and the severity of the building). The depth of such a foundation is above the soil freezing line. At the same time, frost heaving is taken under control and compensated by external insulation of the slab.

Additional arrangement of heating allows you to get a foundation and a warm floor near the house at the same time. This design saves not only weight, but also money. The amount of concrete for casting the base is reduced by a third. Reduced construction costs.

Benefits of an insulated foundation

We list the advantages that make the insulation of the foundation slab a necessary element of construction:

• Saving concrete, reducing construction costs.
• Speeding up construction time.
• Reducing heat loss and reducing utility bills.
• Improving the indoor climate.
• Increase the durability of the foundation slab and the entire structure.

Such high merits indicate that the insulated slab foundation is one of the best house foundation designs.

Foundation slab insulation updated: February 26, 2018 by: zoomfund

Building a country house is the dream of many of us. But in order to provide the necessary conditions for the 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 the level of heat loss increases, but also there is a danger of destruction of the underground structures of the structure.

In the suburban area

Due to the high-quality insulation of the foundation and the basement, heat is retained in the room, the penetration of groundwater is prevented, and protection from low temperatures is also provided. In order to prevent the impact of an aggressive environment on the foundation of the house, protective measures are taken, and the most important of them is external thermal insulation.

Insulation requirements.

To obtain a high-quality result, it is not enough only the professional implementation of all activities.

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

It is rather difficult to choose a heater that is optimally suited for a specific purpose both in terms of quality and from the financial side. After all, today you can find many options for heaters of various price categories and from different manufacturers.

Do-it-yourself installation of extruded polystyrene foam on the 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 value, 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 heat insulator must withstand heavy loads of underground compressive effects. For example, the impact of the soil, which increases in volume when it freezes.
3. Low thermal conductivity. The heat insulator must have a reduced thermal conductivity to ensure good thermal insulation.
4. Long service life. A heat insulator should have approximately the same lifespan as a building, because its replacement is a rather laborious process.

Given all these requirements, you can choose the most suitable material for warming the house outside with your own hands.

Coating waterproofing and foam

The choice of heat insulator

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

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

Styrofoam

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

Penoplex installation

The main advantages are:

1. Low degree of thermal conductivity. Allows you to keep the heat in the room. 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 high humidity conditions 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 influences. The material is not exposed to microorganisms, mold and fungi.
5. Environmental friendliness. Substances that are harmless to human health and the environment are used in the production, so expanded polystyrene is also used in the food industry.
6. A light weight. Thanks to him, the insulation of facades becomes easy and does not take much time.
7. Heat resistance. When ignited, fire-resistant grades of polystyrene foam are prone to self-extinguishing.
8. Noise isolation properties. This is especially important for owners of houses and apartments in noisy areas. The use of polystyrene foam sheets 3 cm thick for insulation can reduce noise by 25 dB.
9. Vapor resistance. The indicator depends on the density and structure of the expanded polystyrene grade. Varieties with low vapor permeability are similar in this indicator to some types of wood: pine, oak.
10. Chemical resistance. The substance is not exposed to the aggressive action of ethers and alcohols, however, it is destroyed under the influence of solvents.
11. Resistance to mechanical influences. The mechanical strength during stretching is about 20 MPa.
12. Relatively low price, which increases the availability of the material for many consumers.

Wiring diagram

So, expanded polystyrene is an ideal option for use in various purposes, especially for thermal insulation of the foundation.

Liquid polyurethane foam

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

This is one of the few materials that are both a heat-insulating, vapor barrier and waterproofing layer. They allow you to significantly save money and labor costs during the performance of thermal insulation work.

cutaway

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. Significant strength. Due to good indicators of density and strength, the material is able to withstand large mechanical loads without losing its operational properties.
5. Absolute sealing, which is very important when performing any kind of insulation work.

Liquid polyurethane foam

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

Protection is carried out by applying liquid rubber or facade paint, which prevents the loss of waterproofing properties and increases the 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 is now widely used in various fields of construction.

Formwork for the blind area

The advantages of the material are:

• low water permeability;
• low thermal conductivity;
• resistance to chemical action of inorganic 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 internal and external insulation of buildings, roofs, is an integral part of sandwich panels, etc. One of the most common varieties is penoplex.

Insulation of the foundation from the outside with foam plastic is relevant and popular due to its excellent performance. Such plates have increased strength and withstand huge loads, providing excellent waterproofing and groundwater drainage.

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

Foundation thermal insulation

The use of modern methods of thermal insulation is of great importance, especially in areas with harsh climatic conditions. This prevents a significant part of heat loss and freezing of soils, which increase in volume, which leads to a rise in their level.

Insulation of the foundation with polystyrene foam

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

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

The video tells in detail about the insulation of the base of a residential building with your own hands.

The process is carried out as follows:

1. Foundation preparation. This stage can be carried out both during the construction of the building, and after its completion. To do this, dig out the foundation, clean it of soil, debris, rust and grease.
2. Sheet selection. In this case, you need to pay attention to two factors: density and thickness. Basically, sheets with flame retardant additives and a density of 35 kg / m3 are used.
3. Waterproofing. This will prevent the impact of groundwater and its penetration through the insulator layer.
4. Fastening polystyrene 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 the 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 building a building on wet soils.
7. Basement insulation. The basement also needs to be insulated in the same way, followed by finishing. After the glue dries, the panels are additionally fastened with nails.
8. Soil warming. The event involves isolating the surrounding land with a blind area insulated with expanded polystyrene plates.

Insulation of the foundation and blind areas can significantly increase the temperature in the structure and protect the base from destruction.

Foundation insulation with liquid polyurethane foam

It is considered a fairly effective method that reduces heat loss by 20–25%.

The main difference is the method of application using a special spraying unit.

To do this, two liquid components are mixed with each other, forming a thick foam. When applied, it expands and hardens, forming a protective seamless layer with excellent thermal and waterproofing properties. The optimum application thickness is 60 mm.

wooden structure

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.

When solidified, the foam changes color. When performing work, various problems can arise related to equipment and neglect of weather conditions.

For example, when applied in sub-zero temperatures, cracks may occur, which must be repaired in the future, otherwise water may accumulate in them and freeze. After polymerization, the polyurethane foam layer has low plasticity.

Foundation insulation with EPPS

As a rule, not all heaters are suitable for thermal insulation of the base. To choose the right material for this purpose, you need to take into account 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, foam plastic, since this material is more durable and has excellent performance characteristics.

Blind area with trays

For this purpose, you need to purchase heat insulator plates and suitable glue for fixing it. After that, a number of preparatory activities should be carried out:

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

Fastening of plates to the outer section of the foundation is allowed 1 minute after applying the adhesive. If the panels have a large area, you need to apply the adhesive in several strips using a comb trowel. If the plates have locks, then a few days later the seams are sealed with mounting foam, and the plates themselves are additionally fastened with dowel nails.

two story mansion

How to insulate the foundation of a wooden house

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

Warming the foundation of a wooden house from the outside will not only create favorable conditions in the room, but also prevent adverse effects on it. For this purpose, expanded polystyrene and its varieties, as well as expanded clay are usually used.

stone finish

Insulation of the foundation PPS or EPPS

Expanded polystyrene has excellent consumer properties, such as a low degree of thermal conductivity and moisture absorption, resistance to the negative effects of 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.

For thermal insulation of only the ground part of the foundation or plinth, a fairly simple installation is required. PPS sheets are simply attached to the surface with glue or special fasteners.

After that, cladding or plastering is performed. At the same time, you should be aware that the installation of insulation does not mean complete waterproofing, so it should be carried out separately to avoid groundwater penetration under the floor.

At the cottage

If there is a basement, it is necessary to insulate not only the ground part of the base, but also that part of it that is underground.

In this case, it is necessary to carry out a complete waterproofing of the walls. For this purpose, a trench is dug around the wooden house, then the foundation is cleared of soil and debris. Further, PPS panels are attached to the surface, after which all this is filled up and rammed.

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

Warming of the foundation with expanded clay

Often, a wooden house is insulated from the outside with expanded clay. However, it has a high moisture content.

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

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 tells in detail how to make the insulation of the base of the house yourself.

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:

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.