The base plate is insulated. Insulation of a monolithic slab

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 of the foundation slab?

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 protect the ground and walls from freezing and, therefore, avoid frost heaving of the ground around the house.

Different foundation designs have different ways of insulation. Tape deep - only vertical walls near the surface of the earth are insulated, 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.

Water absorption characteristics

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 insulation of the slab was done 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 structure). 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.

rfund.ru

Insulation of the foundation slab: work procedure

The slab base withstands significant external influences and is suitable for construction in areas with complex, unstable soils prone to frost heaving, with a high level of groundwater. Insulation of the foundation slab will help to significantly reduce heat loss through the base and reduce the effect of frost heaving of the soil. The building, when the soil moves, rises and falls along with the foundation, which protects the structure of the house from the formation of cracks.

general information

The design of the slab base consists of layers:

• geotextiles are covered with overlapping strips on the sandy layer, the joints are glued with adhesive tape;
• pour gravel, a layer of 15-20 cm;
• pour a leveling layer of cement mortar, 5-10 cm thick;
• be sure to isolate the structure from moisture with the help of roll or coating materials;
• arrange a heat-saving layer;
• cover the plastic film with overlapping strips of 20 cm;
• lay the reinforcing mesh;
• poured with concrete.

Installation and insulation of a slab monolithic foundation is expensive due to the high consumption of building materials. When the soil freezes to a great depth and a significant deepening of the strip foundation is required, the slab installation will be cheaper, and less land work will be required.

Advantages of the slab foundation

The slab base has the following advantages:

• the concrete slab acts as the floor of the first floor, which further reduces the cost of its installation;
• is an excellent option for the foundation of a house, the construction of which is carried out on floating soils, the slab and the whole house with it move simultaneously with the soil;
• you can mount the plate on any type of soil, even on peat bogs and swampy areas;
• the slab is erected above the level of soil freezing; thanks to the sand cushion, frost heaving practically does not affect the structure;
• reinforced concrete slab is not subject to shrinkage;
• suitable for building up to 3 floors.

Insulation of the foundation slab reliably protects it from deformation during seasonal heaving of the soil and prolongs the life of the structure.

Advantages of slab thermal insulation

Expanded polystyrene, polystyrene, polyurethane foam are used as heat-insulating material. Mineral wool is unsuitable due to its low strength and high moisture absorption.

There is a technology for mounting a Swedish plate. The main difference is that the concrete structure is built on a layer of heat-saving material, thanks to which the soil under the house does not freeze and does not heave.

The main advantages of the Swedish plate are:

• the construction of the foundation and the laying of communications are carried out in one technological cycle;
• the heat-saving layer allows you to increase the efficiency of the warm floor;
• installation of the foundation is carried out without involving a large amount of construction equipment.

Around the building, a drainage system is provided, consisting of pipes for draining rain and melt water.

The design of the plate contributes to the transfer of all loads from the building to the layer of heat-saving material, therefore, increased requirements are imposed on the materials used.

Disadvantages of slab foundation

A slab foundation is not always the best option. It is always necessary to carry out all the necessary calculations in advance and select the most suitable type of foundation for the house.

Disadvantages of the plate:

• not suitable for erection in areas with a slope;
• to build a house with a basement on a slab, you need to deepen it to a great depth, it will be very expensive;
• it is difficult to repair communications under the foundation slab;
• during construction in winter, additional costs will be required for heating concrete and maintaining the desired temperature on the site.

A slab foundation is erected only when a strip foundation is not possible.

Materials for insulation

The table shows the materials used to insulate the foundation slab and their characteristics:

№Heat-insulating materialCharacteristics

1	Styrofoam	Consists of cells filled with air. It is produced in the form of sheets, has insufficient density, so its surface needs additional protection.
2	Extruded polystyrene foam	Able to withstand significant compressive loads without changing its size and structure. It is produced in the form of rectangular sheets with small cells filled with air. Stack sheets in 1 or 2 layers. The second layer must be laid out so that the seams of the sheets of the first and second rows do not intersect. During installation, provide holes for moisture removal.
3	polyurethane foam	It is a kind of foamed plastic with many pores filled with air bubbles. The composition is prepared directly at the construction site. The two components are mixed, resulting in a dense hard foam, which is applied to the surface. The plate insulated with polyurethane foam has high rates of heat and sound insulation, withstands moisture. Refers to low-combustible materials, and some brands are slow-burning.

Most often, extruded polystyrene foam is used as a heater under the foundation slab.

Installation of an insulated plate

The construction of a monolithic slab base requires the performance of all calculations, taking into account geological, climatic conditions and the mass of housing construction.

Insulation of the slab foundation allows you to save significant funds on heating the premises during operation.

Site preparation

At the stage of creation, the project must take into account that the area for the foundation slab must be wider than the housing construction by at least 1 m on each side.

Instructions for performing preparatory work:

1. The site where construction is being carried out is cleared of debris, the root system of trees and shrubs.
2. Mark the position of the plate according to the project.
3. They clean and remove the fertile layer of soil. The degree of deepening of the plate depends on the geological and climatic conditions. Most often, the thickness of the plate varies from 20 to 30 cm, less often the base is buried by 50 cm.
4. They dig a pit, manually level its bottom and side walls.
5. Pipes are installed around the perimeter to drain rain and melt water.
6. Lay the geotextile in overlapping stripes. The material should cover the bottom and go to the walls along the entire height.
7. Drive in wooden stakes or metal rods. Stretch the cord strictly horizontally. It will serve as a guide for uniform backfilling of sand and gravel.
8. Sand is poured, 20-30 cm thick. Sand is evenly distributed over the entire area, moistened with water and compacted well.
9. Spread geotextiles.
10. Crushed stone is poured, evenly distributed around the perimeter, carefully rammed.
11. Conduct all necessary communications. They dig trenches under them in rubble a little wider than the section of pipes. The pipeline is laid, a layer of sand is poured on top.
12. The sandy surface is leveled.

If the pipeline is laid before the crushed stone compaction stage, the pipes may crack.

Plate insulation

Step-by-step instructions for insulating a slab of a monolithic foundation:

1. They mount a removable formwork from boards, install props so that the structure does not fall apart under the weight of concrete.
2. A layer of concrete is poured, 50 mm thick.
3. After the cement mortar has completely hardened, foam sheets are laid on it butt against each other and glued. The adhesive composition is applied with dots along the perimeter of the sheet and in the center. A layer thickness of 10-20 cm is sufficient. The joints of the row are placed in a checkerboard pattern, with an offset of 1/3. When laying in two rows, the joints must not intersect.
4. Spread dense polyethylene with overlapping strips. The joints are sealed with adhesive tape.
5. The reinforcing cage is laid, the formwork is poured with concrete.

After the slab has dried, the formwork is dismantled, the side walls are thermally insulated with the same material that was used for laying under the slab.

The insulated plinth helps to increase heat saving inside the room.

When installing insulation on bituminous insulation, you need to wait for it to dry completely. If laying on a wet layer, the materials may be damaged and the effect of thermal insulation and waterproofing will decrease.

Rules for installing heating pipes

When installing the UWB, heating pipes are used. There are such rules for their installation:

• A denser laying of pipes allows you to get higher temperatures for heating the room.
• The distance between the outer walls and pipes should not exceed 150 mm. Closer to the center, the laying step can be increased up to 250 mm.
• To minimize hydraulic losses, the length of one loop should not exceed 100 m.
• Do not lay pipes closer than 100 mm apart.

It is impossible to mount heating pipes at the junctions of monolithic plates. In this case, it is better to lay two circuits. The pipeline crossing the joint is insulated with steel sleeves 30 cm long.

How to make a warmed Swedish stove with your own hands can be seen in the video: The insulated foundation slab reduces heating costs during operation and helps to reduce the level of frost heaving of the soil. Thanks to this, the life of the foundation is extended, and living in the house becomes more comfortable.

Related articles:

kakfundament.ru

Insulation under the foundation slab: step by step instructions

The monolithic slab base of the foundation has proven itself perfectly when operating in weak and heaving soils. The annual freezing of soils in winter leads to uneven lifting and settlement of the slab base, which contributes to the occurrence of mechanical deformations that can cause the destruction of the slab itself and the building built on it.

A layer of horizontal insulation is capable of reliably isolating the foundation slab from the zone of frost heaving, contact with soil moisture and preventing freezing.

Benefits of slab insulation

Horizontal slab insulation

High-quality insulation of the foundation monolithic slab guarantees the durability of the building and long-term operation without the need for unplanned repairs. Particularly relevant is the insulation of the foundation slab under residential buildings, when it is possible to avoid significant heat losses on the first floors of the house.

Insulation of the foundation slab must be performed for the following reasons:

• Providing increased waterproofing of the foundation.
• Significant reduction in heat loss.
• Saving money on heating a residential building, a real mode of heat saving.
• Prevention of the formation of condensate that can destroy the building structures of the building.
• Increasing the comfort of living.
• Stabilization of temperature in the internal premises of an operated residential building.

Materials for insulation of a monolithic slab foundation

fundamentaya.ru

Insulation of a monolithic foundation slab from the inside

Insulation of the slab of any foundation is one of the most important things in the construction of a house. It is best to do this in the warm season, and you can not do this in rainy weather. Insulation of a monolithic foundation slab is especially important for cold regions, where the soil freezes at great depths. Heaving soils during freezing can increase in volume, which leads to deformations of the entire building. Therefore, it is so important to take care of the external insulation of the foundation. This will help reduce the heat loss of the entire future building and preserve its durability.

What does foundation insulation provide?

The better all the work is done, the longer and more reliably the building will stand idle. And most importantly - the house will remain warm even in severe frosts. Do not forget that most of the cold penetrates the house through the foundation. And if the building has a basement (billiard room, gym), then you should take care of the internal insulation. This is especially important if the basement is not heated. But the most important is the external insulation of any residential building.

The main reasons why insulation is necessary:

1. Improvement of waterproofing properties.
2. Reduced heat loss.
3. Reducing home heating costs.
4. Prevention of condensation on the walls.
5. Stabilization of the internal temperature of the building.

All this will help not only to always feel comfortable in your home, but also increase its lifespan.

What kind of insulation to use for the foundation?

The most important part of the job when insulating a fresh foundation slab is required is the selection of the right material. It should not deform under the pressure of the soil and absorb moisture. These are the most important parameters of any thermal insulation. Soft materials such as mineral wool will not work. The best option is polyurethane foam and extruded polystyrene foam. Both of them have excellent thermal insulation characteristics and a fairly low cost, which is also important in construction.

polyurethane foam

This material is universal, as it combines not only thermal insulation, but also sound and waterproofing properties. To use this type of insulation, you will need special equipment, as it must be sprayed. For full insulation, 50 mm of insulation thickness, laid in several layers, is sufficient. All joints after insulation must be sealed.

This material has a number of positive properties:

• low thermal conductivity;
• good adhesive properties;
• reliability;
• durability.

And most importantly, when using polyurethane foam, there is no need to use additional funds for steam, water and waterproofing. It has only one drawback - the need to use special equipment. Therefore, for this method of insulation, either considerable capital investments or the help of experienced specialists with the appropriate equipment will be required.

Extruded polystyrene foam

This type of insulation is significantly lower than polyurethane foam, it is easier to install. Such material consists of plates that do not pass and do not absorb moisture. It retains its thermal insulation properties for a long time even in cold regions. Advantages of extruded polystyrene foam:

• high strength;
• long service life;
• reliable thermal insulation properties.

It is most often used if necessary to insulate the foundation, since it can be mounted independently, without the use of additional equipment.

Extruded Styrofoam with Grooves

This is a new kind of insulation. Milling grooves on the surface of expanded polystyrene boards are great for insulating the foundation. It is used together with a geotextile cloth as fastening drainage. Its main properties:

• good thermal insulation;
• protective layer of waterproofing;
• waterproof.

Insulation of the foundation with polystyrene foam

To insulate a monolithic slab, you can use both polystyrene foam and polyurethane foam. But the first option is preferable. Expanded polystyrene is the most efficient and least expensive, and most importantly - easy to install. Before proceeding with its installation, it is recommended to lay waterproofing, then you can start laying extruded polystyrene foam boards.

The most effective method of insulating the foundation with this material is to use it in areas of soil freezing. The insulation is mounted to the freezing depth. This is quite enough. When insulating, special attention should be paid to the corners: in such places, the used polystyrene foam should be thicker than in other areas. Along the perimeter of the building, it is imperative to perform soil insulation. To do this, under the design of the blind area, it is necessary to place a heater.

All rows of extruded polystyrene boards must be laid end to end, from bottom to top. Large seams are filled with mounting foam. This will provide high tightness, heat-insulating and waterproofing properties. The plates are planted on polymer glue or mastic, and then pressed with a layer of soil. When insulating, it is important to take into account that all the plates are of the same width; already used material cannot be used, this can violate the tightness. This method is suitable for all types of foundations, including monolithic ones.

Insulation of the foundation with polyurethane foam

When insulating a monolithic foundation using polyurethane foam, it is important that there are no gaps and gaps. The insulation must form a completely closed loop. This will achieve maximum thermal insulation properties. Its spraying on the foundation is carried out using special equipment. The material then hardens within 20 seconds. In general, the whole process of installing insulation is quite simple and fast. The application of polyurethane foam is done in several layers, after each of them dries. One layer should be approximately 15 mm thick.

Upon completion of all work, waterproofing and sprinkling of the foundation with soil are carried out. Equipment for the installation of such insulation can be purchased at specialized stores or rented. But it is easier and faster to use the services of professionals.

rfund.ru

Some effective building technologies have been created recently. This is due to the appearance on the market of new materials with better or unique characteristics. Some of these techniques can be replicated by the average person with relatively little study of the relevant materials. In this article, we will consider the process of warming with our own hands the foundation of a private residential building, another, relatively small structure.

Why you may need to insulate the foundation slab

Improving the insulation parameters of a building will make it easier and cheaper to operate. Only this fact is quite enough to think about carrying out the corresponding work. Energy resources, despite temporary market fluctuations, will always be of high value. By reducing their consumption, it will be possible to count on significant savings in money.

It should also be noted that the correct engineering calculation will help to move the dew point beyond the contour of the main part of the building. This means that moisture will not condense inside the structures. Thus, after modernization, the conditions for the appearance and development of mold will worsen, hidden corrosion processes will stop.

Separately, it is necessary to consider the heaving of soils. It takes place during the winter. These mechanical influences are capable of creating great pressure on the structural elements of the building. High-quality insulation of the foundation slab will prevent such and other harmful effects listed above.

Any technology becomes clearer on examples confirming the expediency of its application. In this case, you should pay attention to the foundation "insulated Swedish plate". Here are the main parameters of this foreign technique, which is increasingly used today in domestic private housing construction:

• It is a single structure made of cast concrete with reinforcement and stiffeners. It is installed on a pillow and surrounded by styrofoam boards.
• Sand is initially poured under the main insulation and on the sides of it.
• A system for collecting water and diverting it to drainage is preliminarily installed.
• The blind area along the contour reduces the load on the drainage complex.
• Ensuring comfortable temperature conditions is carried out using the "warm floor" system. It is built into the foundation at the stage of its creation.

The name itself defines the country of origin of the technology. In Sweden, it has been successfully used for more than half a century, and in Russia, private individuals and construction companies have been using similar methods for about ten years. Such terms are quite sufficient for reasonable conclusions. Practical tests have confirmed the presence of the following features:

• This foundation construction technology is well suited for the construction of 1-2 storey houses. For higher buildings it is necessary to order an individual project. It will then have to be coordinated in all official instances.
• In order to completely eliminate the possibility of flooding the building during the flood period, it is necessary to install sand bedding of the required height. To determine it, you can use statistical data for the desired region with maximum levels. If necessary, additional measures are taken to improve the drainage and waterproofing system.
• On sandy soils, you can save money during the construction process. There is no need for a productive water drainage system.
• Working with concrete, as in all other similar cases, is recommended only during the warm period. It is possible to fill the foundation in winter, but this will be accompanied by increased costs and increase the risk of marriage.
• This design works especially well in combination with a “warm floor”. In particular, when the heating is turned off, even in the cold season, heat will remain in the house for 72 hours.
• A professional company can complete a full cycle of work in 3-4 weeks.

Material for creating a high-quality insulating layer

You can make a choice based on analogues of materials that are used in Swedish technology. But first, let's rule out the unsuitable options:

• Mineral wools of different types do not have the necessary rigidity, strength and absorb water too well.
• Expanded clay, other materials from granules. They also will not work, as they cannot become a dense, moisture-proof basis for the future foundation.
• Polymeric foam materials that are created directly on the job sites. Some of them can be applied. But the implementation of such a project will require certain skills. You will also need special equipment.

By the method of elimination, we found the "winner" of this correspondence competition. This is a foam polystyrene of factory production, penoplex. We list below those characteristics of the material that will be useful for solving the tasks:

• Its method of production implies the release of standardized products. Thus, if you purchase penoplex of a well-known brand, then there will be no doubt that each plate will have the same parameters.
• Accurate dimensions and low weight will facilitate transportation, storage, and installation operations.
• Uniform distribution of closed bubbles in the foam structure provides excellent thermal insulation properties. To produce a full-fledged insulation of a monolithic foundation, it will not be necessary to create a too thick layer.
• This material is durable and waterproof. Many types of plates are made from it with special grooves along the edges, which makes it possible to ensure the tightness of butt joints without additional means.

Warming of the slab foundation

We have found out the main parameters of this technique, so we can proceed to the description of the working operations. Consider the steps that are used to insulate the foundation slab:

• For this group of works, it will be enough to create a layer of high-quality foam plastic with a thickness of not more than 10 cm. It can be formed from two rows of plates that are stacked in a checkerboard pattern with a joint overlap of the joint areas.
• Site preparation should be carried out taking into account the geology of the site, soil characteristics. When creating a recess, the bottom must be made even, so it is recommended to use manual labor in the final stages.
• The sand is backfilled and compacted, after which a temporary formwork is installed, the first layer of concrete is poured without reinforcing elements.
• When the base has hardened, foam boards are laid on it in the order indicated above. They are covered with a thick plastic film on top. The seams between the individual strips are carefully sealed with wide adhesive tape.
• Next, the main foundation of reinforced concrete is created.
• After it hardens, foam boards are attached to the end parts with an adhesive composition.

mynovostroika.ru

Insulation of a monolithic foundation slab with expanded polystyrene

On unstable soils, it is difficult to arrange a solid foundation. In such cases, a slab base is used. It acts as the foundation of a small deepening, drifting around the site, when moving soil masses. Since the entire structure moves, no destructive stresses arise.

For the proper operation of this type of foundation, it must be protected from freezing. Insulation of a monolithic foundation slab:

• prevents the destruction of concrete from temperature differences;
• contributes to the warm floor of the first floor;
• makes it possible to save on building heating;
• reduces the heaving of the soil under the building.

The choice of insulation

Not every, even the most effective material, is suitable for working in the ground or in its vicinity. When choosing a material, you need to be guided by:

• moisture resistance. Being saturated with water from the soil, the product loses its insulating properties. Expanding when freezing, moisture violates the integrity of the coating, reducing all work to nothing;
• strength. Seasonal movements of soil masses create tangible pressure on the material. It is especially noticeable in rocky soils. Sharp edges can push through products, leaving cracks or breaks in it;
• resistance to aggressive environments. Soils are often chemically and biologically active. Groundwater may contain high concentrations of salts. All these factors lead to premature destruction of the insulation.

When installing insulation inside the building, the material must be non-combustible. If there is a possibility of ignition, no harmful substances should be released that can cause suffocation.

With all this, the service life of the insulation should not be less than the service life of the finishing material. In this case, you do not have to change it before the coating becomes obsolete. Otherwise, you will have to dismantle the finishing sheet that still meets the standards.

Often, extruded polystyrene foam is used for zero-cycle work. Insulation of the foundation slab with expanded polystyrene, made in accordance with all the rules, allows you not to worry about the safety of concrete and saving heat.

Characteristics of expanded polystyrene

Expanded polystyrene is used for thermal insulation of the foundation slab:

• outside;
• from within;
• in the body of concrete

External insulation technology

The height of the plate can be from half a meter. Freezing around the perimeter is the most dangerous for the foundation. Therefore, basically, the insulation is attached precisely to the side surfaces.

Before covering the foundation with a layer of insulation, it must be waterproofed. Despite the fact that expanded polystyrene is waterproof, the coating is not seamless. Moisture penetrates into the seams between the plates, which can destroy the plate.

Waterproofing occurs by applying bituminous mastic or melting along the surface and edges of the paraffin slab. The second method is more economical and reliable. With the help of a gas burner, pieces of paraffin are melted. The material is evenly distributed over the surface, soaking into it.

Waxing closes the pores of the concrete, creating a barrier to moisture. Full adhesion contributes to the exclusion of insulation peeling. This means that you can easily attach a heater to it.

Expanded polystyrene plates are mounted on glue or on a cement-sand mortar. The first option allows you to conduct insulation at sub-zero temperatures. The underground part is fixed only by gluing. This is necessary to avoid violation of the hydrobarrier.

The basement part of the insulation of the slab foundation with polystyrene foam is additionally fixed with plastic dowels. To do this, holes are drilled through the glued plates. They go through all the insulation and part of the foundation.

Glue is applied along the perimeter of the plate and in several strips in the center. It is held for 1 minute and the plate is pressed against the surface for a couple of minutes. After gluing, the bottom plates are sprinkled with a layer of sand. This helps secure them in their mounting position.

The second row of insulation is mounted with offset seams. It is desirable to make a dressing and horizontal joints. This helps to avoid cold bridges.

If the thickness of the plates is not enough, the insulation is carried out in two layers. Products with maximum thicknesses are taken to avoid the installation of several layers. Plates of the upper layer must overlap the seams of the lower ones.

Fixation with umbrellas is carried out at five points of the plate. The dowels are mounted after the plates are completely glued, but not later than three days later.

After installation, the seams are sealed with mounting foam. Excess foam is cut off and the surface is plastered over the grid. The mesh is necessary for better adhesion of polystyrene foam and plaster.

Internal insulation technology

When insulating a monolithic foundation slab from the inside, the material is laid in two ways:

• On top of the plate;
• In the body of concrete.

With the first method, the sequence of work is as follows:

• waterproofing is arranged on the foundation slab, with entry to the wall;
• logs are screwed on top of the waterproofing layer;
• a layer of insulation is arranged between the lag;
• a waterproofing film is attached to the lags on top of the insulation;
• a plank base, plywood or OSB boards are mounted on the film;
• a cork, polyethylene foam or needles underlay is laid over the subfloor. A finishing floor is mounted on it.

You can do without lag. In this case, the slab foundation is completely insulated with polystyrene foam. The material is laid in a continuous layer. Immediately on top of it, a substrate and a finishing floor covering are laid.

When installing in concrete, the following work is performed:

• the base plate is waterproofed;
• a layer of insulation with a thickness of at least 100 mm is arranged. It is better to use products with a locking system;
• a PVC film with a density of at least 1.42 g / cm3 is laid on the insulation;
• reinforcing mesh is laid. In its role can be a masonry mesh with a cell of 100 * 100 mm;
• the surface is poured with a screed no thinner than 5 cm;
• the finish coating is laid on the screed.

For internal insulation, only self-extinguishing polystyrene foam should be used. For installation under the screed, products of the G4 flammability class can be used.

Insulation of the body of the foundation slab

Warm concrete is used in many areas of construction. It can be purchased in the form of a ready-made mixture or manufactured in the conditions of a construction site. For preparation, granulated polystyrene foam is added to the initial mixture for the formation of the foundation slab.

For the device of structural elements, polystyrene concrete with a density of D1200 is used. When preparing 1 cube, the composition includes:

• 300 kg of cement M400;
• 1.1 m3 of expanded polystyrene granules. It is better to use granulated rather than crushed material. It has the shape of a ball, which leads to a better enveloping of the cement mixture;
• 800 kg of sand;
• PAD. Often, saponified resin is added. Its presence in the composition provides better adhesion and increases heat-shielding properties.

When creating such concrete, you need to remember about shrinkage. It is 1 mm per 1 m of surface. The plate needs to stand for some time after curing. On the surface it is necessary to arrange a leveling screed.

The flammability class of such a product is G1. The concrete itself does not burn, but the insulation granules are exposed to fire. As a result, pores are created in the body of the foundation slab. They reduce the density of the structure and increase its moisture absorption.

The thermal conductivity of such a plate will be approximately 0.105 W / (m * C). The product requires additional insulation of the slab foundation from below. The thickness of the insulating material will be less than plain concrete.

The choice of the type and technology of insulation of the foundation slab depends on the design features of the building and the construction site. Choosing the optimal solution is based on the data of the heat engineering calculation and comparison of the estimated cost.

tstinfo.ru

Insulation of the slab foundation - Technologies, subtleties, nuances

Each developer, when choosing a foundation structure for a future building, is guided primarily by its cost, reliability and durability. An ideal foundation that combines all these qualities are monolithic foundation slabs that can be built on various types of soil. But concrete has a high thermal conductivity, so developers need to take care of the insulation of load-bearing structures even in the process of performing construction work.

Warming methods

Warming of the slab foundation must be carried out in the part that is located in the zone of soil freezing. The developer should lay insulation under the foundation slab, as well as under the outer blind area, which is necessarily created around the building. And also the basement of the building and the upper part of the foundation wall should be closed with special material. Timely insulation of a monolithic foundation slab will protect the soil adjacent to the building and its walls from freezing, which will prevent frost heaving of the soil and minimize heat loss at home.

When planning the insulation of a slab foundation, the developer must take into account the type of supporting structure:

1. Tape (deep). Various materials are used for insulation, which are laid on the vertical surfaces of the supporting structure, above the ground surface.
2. Shallow strip foundation. For insulation, tile materials are used, which are laid on the sole and vertical surfaces of the supporting structure.
3. Pile. Only the side surfaces of the piles deepened into the soil are subjected to insulation.
4. Monolithic tile construction. The foundation slab is insulated not only from below, but also on the sides.

The benefits of timely insulation

The insulated slab foundation has a large number of advantages that every developer needs to know about:

1. Developers will be able to save concrete mortar, which is used in large volumes when pouring slab foundation structures.
2. Insulated foundation allows you to minimize heat loss. This has a positive effect on the indoor climate, as well as on utility bills, which skyrocket in the winter season.
3. Accelerating construction time.
4. The useful life of the supporting structure is maximized, since it ceases to be adversely affected by moisture and low temperatures.
5. The insulated base plate prevents condensation on the interior walls of the premises.
6. The service life of waterproofing materials, which are used in the process of building slab foundation structures, is maximized.

What materials can be used to insulate a slab foundation?

Currently, the domestic construction market has a huge range of materials that developers can use when carrying out insulation measures:

1. Polyurethane foam. This material is made of foamed plastic, which has a porous structure filled with air bubbles. This insulating mixture is created directly at the construction site and applied to the foundation structures using special equipment. The components that have entered into a chemical reaction already form a strong foam on concrete surfaces, which hardens almost instantly. This material helps to minimize heat loss, prevents the penetration of extraneous noise from the street into the premises, does not undergo putrefactive changes with constant contact with a humid environment, and is highly resistant to ignition.
2. Styrofoam. This material has been used in the construction industry as a heater for decades. Its main disadvantage is its low mechanical strength, which requires additional cladding.
3. Expanded polystyrene extruded. This material has a fine-mesh structure and is supplied to the construction market in the form of rectangular sheets. It has excellent technical properties, is able to withstand high loads, without changing either the internal structure or the geometric shape. In recent years, developers, when carrying out the insulation of slab foundation structures, use exactly extruded polystyrene foam, since it does not need additional protection and can perform the functions assigned to it for decades.

In recent years, many developers prefer to insulate the foundation with foam plastic. The choice of this material is due to the fact that it is highly resistant to moisture, and also has the lowest possible thermal conductivity. Due to the fact that the slab supporting structure will have to be in contact with a humid environment for many decades, insulation of the foundation with foam plastic will protect the building from its harmful effects.

Extruded polystyrene foam is ideal for thermal insulation of monolithic foundation structures, as it is able to withstand compressive loads. Polyurethane foam plates and penoplex are cellular materials with a closed structure, due to which moisture is not able to penetrate into their cavities. That is why they are involved in carrying out warming measures.

Rules for the insulation of slab foundation structures

Before insulating the slab foundation, the developer must learn about all the features and nuances, as well as the most effective technologies. If the foundation is insulated with foam plastic from the outside, this will protect not only the plates, but also the walls from freezing. In the event that polystyrene foam panels are laid on the inner sides of the walls, the developer will be able to significantly improve the microclimate inside the premises, but at the same time, the slabs and walls of the building will not be protected from freezing. It follows from this that the external insulation of the foundation with foam plastic will be an ideal option for any construction projects.

External insulation of the foundation with polystyrene foam or foam plastic is possible only at the initial stages of construction. If developers miss this moment, then in the future they will only be able to carry out internal insulation of the foundation with foam or polyurethane foam.

Carrying out insulation measures during the construction process

The procedure for warming the foundation with polystyrene foam must be carried out at the initial stage of construction work. Developers should strictly follow the technology:

1. First of all, a pit is dug out, in which a monolithic concrete slab will be created. Its depth should be 1 meter. At the bottom, recesses are made into which drainage pipes are laid, the functions of which are to drain surface water into specially created wells. Such measures will protect not only the foundation, but also the walls of the building from getting wet.
2. After laying the drainage pipes, the bottom of the trench is leveled and a special material, geotextile, is rolled out on its surface. It will prevent the germination of rhizomes of trees and shrubs that can violate the integrity of the supporting structure.
3. A layer of sand and gravel is laid on top of the geotextile. Thus, a sand and gravel cushion is created at the bottom of the pit (thickness is approximately 30-40 cm).
4. Engineering communications are being laid, for example, water and sewer pipes. After their laying, the surface is sprinkled with sand and leveled.
5. A formwork is constructed along the perimeter of the prepared pit. For these purposes, it is customary to use boards or sheets of moisture-resistant plywood. Outside, the formwork must be supported with jibs or stops so that the wooden structure can withstand the load that the concrete mortar will exert on it.
6. A small amount of concrete is poured onto the bottom of the pit, which will create the first foundation layer. After it hardens, the developer must begin to carry out waterproofing and thermal insulation measures.
7. Due to the fact that a monolithic concrete slab will constantly be in the ground and in contact with a humid environment, the developer must perform its high-quality waterproofing. For these purposes, it is customary in the construction industry to use rolled material or coating. The concrete base must be thoroughly cleaned of debris, and then dusted. To increase its adhesive properties, it is recommended to treat it with diluted kerosene or a solvent. After that, a roofing material is rolled out on a prepared concrete base, the canvases of which must overlap. All joints should be treated with mastic, after which experts recommend laying another layer of waterproofing. If the developer decides to use liquid insulation, then he needs to apply it several times to the surface of the concrete base and, after complete drying, continue construction work.
8. The next step is the insulation of the plate. For these purposes, most developers use sheets of extruded polystyrene foam (thickness 15cm). Lay such material, as a rule, in two layers. Care must be taken to ensure that the top sheets overlap the joints of the bottom panels.
9. The reinforcement of the foundation structure is being carried out, due to which its strength and bearing characteristics will increase.
10. The concrete solution is poured in several stages. After pouring the first batch, the developer must use a deep vibrator to remove air and eliminate the resulting voids. After that, the remaining solution is poured.

After the concrete has hardened, the developer can continue construction work. In order to protect the building as much as possible from the harmful effects of harmful environments, he must carry out the internal insulation of the foundation. To do this, sheets of extruded polystyrene foam should be used, which are glued to the floor and walls of the premises and are subsequently finished.

Users of our portal have accumulated vast experience in building foundations. Starting from tape, pile, monolithic slabs and ending with the popular type -, and willingly share their knowledge with novice developers. was no exception and Turkish945. The user spoke in detail about all stages of the construction of an insulated slab foundation for a garage-workshop-boiler room, 7500x7500 mm in size.

Turkish945 Member FORUMHOUSE

I spent a long time analyzing which foundation to choose. As a result, I settled on the type of UWB. At first I thought about making a plate with stiffeners, then without ribs. But one thing bothered me - whether a 10 cm thick plate would withstand a point load from a TA (heat accumulator). Therefore, I decided not to engage in amateur performances, but to order a foundation project.

After the calculation, it turned out that the thickness of the slab should be increased to 20 cm, otherwise there is no guarantee that it will withstand the expected load. Judging that the savings of 30 thousand rubles. (the difference between the thickness of the slab is 100 and 200 mm) this is an unjustified risk, the user settled on the second version of the foundation.

The foundation is a layer between the building and the base, which redistributes the load from the house to the ground. The foundation should not be built by eye and not according to the principle “so the neighbor did”, but designed on the basis of data from a geological study of the soil (this will make it possible to find out its bearing capacity) and with the further collection of all loads from the building.

Having decided on the foundation project, the user hired an excavator to dig the foundation pit. In total, about 50 cubic meters of soil were selected and taken out. In addition, we managed to negotiate with the excavator and at the same time uproot the bushes and trees on the site. For this work, they gave 15 thousand rubles (at prices in the Moscow Region for 2015).

The height error at the bottom of the pit did not exceed 50 mm. Also Turkish945 asked the users of the portal what to do with the grooves at the bottom of the pit, formed after the work of the bucket: clean or tamp, as is, and then pour the “pillow”?

FORUMHOUSE participants advised to completely remove all loose soil.

The user also conceived with the help of hired workers to dig a trench (400x600 mm) around the perimeter of the foundation for drainage. Then lay the geotextile and start compacting the sand cushion. It was not possible to dig a trench, due to the lack of laborers ready to do this work.

Because Turkish945 from the very beginning he doubted the need for drainage, he decided to completely abandon it, saving 40 thousand rubles. Although this decision, according to our users, is very controversial, work has continued. Over the weekend, the user, with the help of a friend, took all the loosened soil out of the pit on a garden wheelbarrow.

Turkish945

When you look at the pit from above, it seems that there is very little loosened soil, and for two it is an easy job. As a result, we worked 4 hours without a break and were very tired.

Here's what happened after the removal of the soil.

Also along the way, extruded polystyrene foam was unloaded (19 packs of 120x60x10 cm in size for slab insulation and 2 packs of 1160x580x50 mm for slab sides), which was brought to the site.

Having finished the preparatory stage, the user spread geotextiles at the bottom of the excavation and proceeded to form a sand cushion. To do this, he needed a vibrating plate ( Turkish945 rented it), but there was a hitch with the sand.

Turkish945 ordered sand from one "local" seller, who promised that he would bring eight cubic meters of clean sand at a price of 5 thousand rubles for KamAZ. As a result, sand with a large amount of stones and clay was brought to the construction site.

I had to manually sort out and throw out foreign inclusions. The work dragged on into the evening. The user also agreed with two laborers that on Sunday they would come to lay the sand.

Because the ordered sand is not enough, Turkish945, having received a discount for non-conformity for the first truck, he ordered a second car from the same seller, and ordered a third KamAZ with sand, just in case, from another supplier.

On Sunday morning, it turned out that laborers who had been hired the day before were being delayed. In order not to waste a day, the user got to work.

Turkish945

I rammed the sand with a vibrating plate weighing 85 kg. Made 4 passes in total. One pass took 30-40 minutes. Sand spilled with water.

By this time, two trucks with sand had arrived. The first - with sand from the seller, who deceived on quality, but gave a discount and swore that this would not happen again. The second truck is from a new supplier. Having unloaded two heaps side by side, Turkish945 I saw that the sand was again with clay. In addition, the heap, which, according to the first seller, should be 8 cubic meters in volume, looks exactly the same as the heap from the second seller, but who brought 6 cubic meters of excellent sand.

Bottom line: the first supplier has completely exhausted the credit of trust and said goodbye to him. Without waiting for the unskilled workers, who promised to arrive by this time, the user and his father-in-law began to take away the rest of the sand on their own.

To bring the layer thickness to "0", they drove in pegs with marks of the required level.

By order of the charter, Turkish945 I decided to call the laborers again and find out where they were. Having received the answer that they are already on the way, the work continued. As a result, the "assistants" arrived in the evening, and in ordinary clothes, and when asked how they were going to work in this form, they replied: "We only came to see the scope of work."

Having looked around, the guys immediately declared a price of 1000 rubles per 1 cubic meter of sand. This is about 30 thousand rubles. for two, for 2 days of work. Saying "goodbye", the developer refused their services.

After all the ordeals, Turkish945 found the guys who quickly scattered and compacted the sand at a price of 1500 rubles. per day per person. In total, 40 cubic meters of sand were used for the sand cushion.

Turkish945

We compacted the sand to the state of the slab. It turned out a flat and solid base.

The next stage is the marking of routes for engineering communications. For the convenience of work, the user made a simple device - “beacons”, driving a “weave” nail into the caps from plastic bottles.

The “beacon” is stuck into the sand, and a roulette ring clings to the nail head.

This allows you to mark the tracks without assistance.

Track lines on the sand were marked with paint sprayed from an aerosol can along a stretched thread.

Having marked the routes, they dug trenches for engineering communications.

The main thing is to observe all the necessary slopes for sewer pipes. 2 cm per 1 linear meter for a pipe with a diameter of 110 mm and 3 cm per 1 linear meter for a pipe with a diameter of 50 mm.

Pipes (under water and heating mains) enter the foundation body in a sleeve - a pipe of a larger diameter. In this case, 110 and 160 mm. Moreover, the entrance of the pipes is deliberately made not at 90, but at 60 degrees. To do this, they took and connected two knees with an angle of 30 degrees.

To check the tightness of communications, you can muffle the outlets and pour water into the pipes. If the liquid level does not change, and there are no leaks at the joints, then the routes can be buried.

Having covered the communications with sand and rammed it, the developer laid out the insulation with the displacement of the plates.

Final variant.

Now we move on to knitting the reinforcing cage. To speed up work Turkish945 I ordered rebar, already sawn to the required dimensions.

Turkish945

When I saw the amount of rebar delivered, I realized that I had made the right decision. And I saved time, and I saved the tool, because I'm not sure that my "Bulgarian" would have withstood such a volume of work.

A special gun was rented for knitting reinforcement, despite the skepticism on the part of portal users about this expensive equipment.

The most frequent complaints: the battery does not hold, does not knit well, the wire gets tangled, but Turkish945 was pleased with the performance of the gun. According to him, the wire got confused only at the very beginning - the first 10 minutes of work, then, having "filled his hand", he knitted with a pistol without marriage.

As for the speed of work, it took about one hour to tie the reinforcing cage in increments of 25 cm with smoke breaks. And wire spools, costing 120 rubles, are enough for about 170 knots.

Being engaged in independent construction, you need to be prepared for various force majeure circumstances - a sharp change in weather conditions, etc. Arriving at the site one day to finish tying the reinforcing cage, the developer saw the following picture.

The monolithic slab base of the foundation has proven itself perfectly when operating in weak and heaving soils. The annual freezing of soils in winter leads to uneven lifting and settlement of the slab base, which contributes to the occurrence of mechanical deformations that can cause the destruction of the slab itself and the building built on it.

A layer of horizontal insulation is capable of reliably isolating the foundation slab from the zone of frost heaving, contact with soil moisture and preventing freezing.

Benefits of slab insulation

Horizontal slab insulation

High-quality insulation of the foundation monolithic slab guarantees the durability of the building and long-term operation without the need for unplanned repairs. Particularly relevant is the insulation of the foundation slab under residential buildings, when it is possible to avoid significant heat losses on the first floors of the house.

Insulation of the foundation slab must be performed for the following reasons:

• Providing increased waterproofing of the foundation.
• Significant reduction in heat loss.
• Saving money on heating a residential building, a real mode of heat saving.
• Prevention of the formation of condensate that can destroy the building structures of the building.
• Increasing the comfort of living.
• Stabilization of temperature in the internal premises of an operated residential building.

Materials for insulation of a monolithic slab foundation

The choice of materials for insulating the slab base depends on a number of specific conditions, first of all, on the possibility of attracting special equipment (polyurethane insulation must be performed using a special PPU unit for spraying insulation), the availability of a sufficient amount of free funds for the purchase of insulating materials.

Usually, the insulation of foundation structures is performed using the following materials:

One of the best insulation - foam

• Polyurethane foam is a type of foamed plastic that is permeated with pores with air bubbles. The composition for PPU insulation is made directly at the construction site, for which two compositions are mixed, which, as a result of a chemical reaction, form a strong hardened foam. Different ratios when mixing the original ones make it possible to obtain insulating compounds with different qualities, suitable for insulating bases from different materials (including reinforced concrete). PPU has unique qualities: it contributes to the preservation of heat in the room; reduces noise; improves sound insulation; does not decompose under the influence of excessive moisture; resistant to a number of chemical liquids. The material is highly resistant to ignition (some brands of PPU are not capable of igniting, they belong to the group of slow-burning materials).
• Styrofoam - the structure of the material consists of a foam containing pores filled with air. Styrofoam is used to insulate building structures, including foundations, but the surface of such insulation requires additional surface protection due to the low mechanical strength of the material.
• Extruded polystyrene foam - produced in the form of rectangular sheets with a fine-meshed structure. The material has unique properties - the ability to withstand high compressive loads without changing the geometric dimensions and internal structure. Extruded polystyrene foam is widely used to perform thermal insulation of the foundation slab without additional protection. It is very important when using material for insulating foundation slabs to provide special holes for the free exit of soil moisture.

Foundation slab insulation technology

When installing the foundation slab insulation, horizontal and vertical insulation is used, in which a layer of insulation is laid under the slab base or along the side walls of the foundation structure. The most commonly used insulating material is expanded polystyrene or polystyrene. Watch a video on how to insulate a foundation slab with polystyrene foam.

Insulation is laid during the installation of the foundation according to the following technology for performing insulation (consider the option of insulating the foundation with polystyrene foam):

1. To begin with, on the building site, the location of the foundation for the building is marked.
2. The top layer of the mainland soil must be removed to the depth of laying the foundation slab, the bottom of the excavation should be as even as possible.
3. The prepared area is covered with coarse sand, which needs to be compacted using vibrorammers. A small layer of concrete is poured over a layer of sand, for which a temporary formwork is put up.
4. After the concrete screed has hardened, lay out the insulation from polystyrene foam plates, making sure that the mounting grooves match as much as possible. Large gaps between the insulation plates should not be allowed.
5. A layer of polyethylene film is laid on top of the stacked polystyrene plates, which is glued together with a special adhesive tape.
6. A construction formwork is being erected for pouring the slab base, into which a spatial frame of reinforcement with a diameter of 10 mm or more is mounted. Concrete is poured from the corner of the slab foundation, evenly leveled and compacted with a vibrator.
7. The foundation slab gains strength in about 28 days, the formwork can be dismantled two weeks after the structure is poured - by this time the foundation is gaining up to 70% strength.
8. The side walls of the foundation slab are additionally insulated with expanded polystyrene plates.

The insulated monolithic slab will serve for many years without destruction of structures from the influence of adverse factors.

The Swedish plate is an insulated monolithic slab foundation of small depth. The main feature of this technology is that the entire base of the house is based on a layer of insulation (under the stove). Under a warm house, the soil does not freeze and does not heave. Such a foundation is suitable for any soil, at any depth of groundwater.

This technology is based on the basic principles of design and construction shallow foundations on heaving soils described in Organization standard (STO 36554501-012-2008), developed by the Research, Design and Survey and Design and Technology Institute of Foundations and Underground Structures (NIIOSP) named after. N.M. Gersevanova (FSUE NRC "Construction"), FSUE "Fundamentproekt", Moscow State University. M.V. Lomonosov (Faculty of Geology, Doctor of Technical Sciences L.N. Khrustalev) and the technical department of PENOPLEX SPb LLC.

The "Swedish plate" technology combines the device of an insulated monolithic foundation slab and the possibility of laying communications, including a system of water floor heating. An integrated approach allows you to get in a short time an insulated base with built-in engineering systems and a flat floor, ready for laying tiles, laminate or other coatings.

The main advantages of the insulated Swedish plate:

• The construction of the foundation and the laying of communications are carried out in the course of one technological operation, which makes it possible to reduce the construction time.
• The ground surface of the foundation slab is ready for laying the flooring;
• The PENOPLEX FOUNDATION® thermal insulation layer, about 20 cm thick, reliably protects against heat loss, which means a significant reduction in the cost of heating the house and an increase in the efficiency of the "warm floor" system;
• The soil under the insulated slab does not freeze, which minimizes the risk of problems with frost heaving of the base soils;
• Laying the foundation does not require heavy equipment and special engineering skills.

Mounting Features

To ensure the normal operation of the insulated Swedish plate (UShP) and prevent frost heaving, it is necessary to provide for the installation of a groundwater drainage system (drainage system along the perimeter of the structure). An important role is also played by the device of non-porous preparation (pillow of coarse sand, gravel). If a combination of crushed stone and sand layers is used, it is necessary to provide for the separation of these layers with geotextiles (when the soil of a fine fraction is located above a larger one). All necessary communications (water supply, electricity, sewerage, etc.) and inputs must be laid under the stove in advance.

The design of the Swedish plate involves the transfer of all loads from the structure (own weight, operational loads, snow loads, etc.) to the insulation layer, which is why high strength requirements are imposed on the heat-insulating material used. The most rational application in this design is PENOPLEX FOUNDATION® heat-insulating boards, which have almost zero water absorption and high compressive strength.

Instructions for use:

• Step 1. Removal of the top layer of soil (usually about 30-40 cm);
• Step 2. Compaction of sand and gravel preparation (coarse sand, crushed stone);
• Step 3. Installation of drainage along the perimeter of the structure and utility pipes;
• Step 4. Laying of side elements and PENOPLEX FOUNDATION® slabs at the base;
• Step 5. Mounting the reinforcing cage on stands;
• Step 6. Laying pipes for the floor heating system, connecting them to the collector and pumping air into them;
• Step 7. Filling a monolithic slab with concrete mix.

The heating system integrated into the foundation design ensures comfortable conditions inside the building. And the use of durable and absolutely moisture-resistant PENOPLEX FOUNDATION® boards as preparation of the base will significantly increase the thermal reliability and efficiency of the underfloor heating system. Ordinary water or antifreeze can be used as a coolant in the system (if in the winter it will not be possible to always maintain a positive temperature in the room). Almost all types of pipes can be used as heating pipelines in underfloor heating systems: metal-plastic, copper, stainless steel, polybutane, polyethylene, etc.

When laying heating pipes, the following rules are followed:

• Higher heat output of underfloor heating is achieved by denser pipe laying. And vice versa, that is, along the outer walls, the heating pipes should be laid more tightly than in the middle of the room.
• It makes no sense to lay the pipes more densely than after 10 cm. More dense laying leads to a significant overrun of pipes, while the heat flow remains almost unchanged. In addition, a thermal bridge effect may occur when the coolant supply temperature equals the processing temperature.
• The distance between the heating pipes should not be more than 25 cm to ensure even temperature distribution over the floor surface. So that the "temperature zebra" is not perceived by the human foot, the maximum temperature difference along the length of the foot should not exceed 4°C.
• The distance of the heating pipes from the outer walls must be at least 15 cm.
• It is not recommended to lay heating circuits (loops) longer than 100 m. This leads to high hydraulic losses.
• Do not lay pipes at the junction of monolithic slabs. In such cases, it is necessary to put two separate contours on opposite sides of the joint. And the pipes crossing the joint must be laid in metal sleeves, 30 cm long.

The purpose of this article is to go beyond the scope of this project and tell on behalf of specialists the basic rules for working with material that can be useful to everyone.

When erecting this type of foundation, extruded polystyrene foam (EPS) was used. In the master class format, professional builders will tell you how to choose and how to work with extruded polystyrene foam when insulating various types of foundations. Namely:

• Why you need to insulate the foundation.
• What to look for when choosing a material for insulation of the foundation.
• How to properly fix extruded polystyrene foam on the foundation.
• What tool is needed for the job.

Why is it necessary to insulate the foundation

The foundation is the underground part of the structure, which transfers the load from the overlying structures to the prepared soil base. Foundations are of the following types:

• Slab, shallow, with spatial reinforcement. This gives the structure rigidity and allows it, without internal deformation, to perceive the loads that occur during uneven movement of the soil.

• Tape - laid below the freezing depth, etc. MZLF - shallow strip foundation, with the depth of the sole above the estimated mark of seasonal freezing of the soil.

• . Insulated Swedish Plate. This foundation is a monolithic concrete slab mounted on a base insulated with extruded polystyrene foam. The system of water underfloor heating and all engineering communications are integrated into the foundation.

This type of foundation is considered the most technologically advanced and energy efficient. In one system, the foundation and the low-temperature heating system are combined, which excludes the formation of local overheated zones and provides comfortable radiant heat. In addition, the foundation is not affected by the forces of frost heaving, because. countermeasures have been taken. Namely, heaving soil was excavated and replaced with non-heaving soil (sand or crushed stone), a drainage system was installed, the blind area and the base of the slab were insulated.

Up to 20% of heat loss from the total heat loss of the building occurs through the foundation.

Kogut Andrey Technical specialist of TechnoNIKOL company

To achieve maximum energy efficiency of the building, it is necessary to create a closed insulated circuit. This means that, in addition to the main structures, such as: walls, roof and plinth, it is necessary to insulate the foundation as well.

In some cases, it is enough to insulate the floor and basement, but when organizing an operated basement thermal insulation of the foundation walls is a prerequisite to achieve the required level of comfort and reduce heat loss.

In shallow strip and slab foundations, thermal insulation can reduce the effect of frost heaving. Soil swelling is formed due to the freezing of water in the soil and its subsequent expansion. Different soils have different degrees of heaving. For example, sands pass water well through themselves, and it does not linger in them. Clay, on the contrary, does not allow water to escape, and due to the presence of a large number of small pores, it has a high capillary suction of moisture. Improper design on heaving soils can lead to serious consequences, up to the destruction of the foundation. If the foundation is left uninsulated, the heat flow will go down and warm the soil, protecting it from freezing. However, the house may not be heated all the time, in which case the soil will heave. Thermal insulation of the foundation and blind area is one of the measures to combat frost heaving.

Basic principles for choosing thermal insulation for foundation insulation

So, summing up all the above, we conclude: foundation needs to be insulated. Not every insulation is suitable for this, but only a material that can work in aggressive environmental conditions. Those. thermal insulation laid on "non-removable" must be moisture resistant, have a long service life, during which it will not lose its thermal insulation properties, and have strength sufficient to withstand the load from overlying structures.

Kogut Andrey

Extruded polystyrene foam (EPS) has a low thermal conductivity of 0.028 W/(m*°C) and a minimum water absorption coefficient of 0.2% by volume. The insulation does not absorb water, is chemically resistant and does not rot. Compressive strength at 2% linear deformation - not less than 150 kPa (~ 15 t / sq. M) and higher. Service life in soils is at least 50 years.

High compressive strength allows the use of XPS in loaded structures (foundations) and ensures the stability of the thermal insulation thickness under load.

The thickness of the thermal insulation layer must be taken on the basis of calculations based on several conditions:

• The purpose of the building (residential, administrative, industrial, etc.).
• The insulation must provide the required heat transfer resistance for this type of building.
• There should be no seasonal moisture accumulation in the structure.

Calculation thickness of thermal insulation for the foundation is made according to the methodology set out in SP50.13330.2012 "Thermal protection of buildings". For different regions, the thickness of the thermal insulation may vary, depending on climatic conditions. It should also be taken into account that increasing the thickness of the thermal insulation increases the energy efficiency of the building and, consequently, leads to a reduction in heating costs.

Choosing the technical characteristics of thermal insulation, we are guided by the following principles:

1. When insulating a strip foundation, when only a vertical wall is insulated, increased strength of the material is not required, because. in this case, the EPS takes loads only from the backfill soil. Therefore, for shallow foundations, grades of extruded polystyrene foam with a compressive strength (at 10% linear deformation) of 150-250 kPa are suitable.
2. When laying XPS boards under the base of the foundation or under the slab, the loads on it increase significantly, respectively, the requirements for its strength increase. In this case, it is recommended to use heat-insulating boards with a compressive strength of 250 - 400 kPa.
3. Especially for UWB, a material has been developed with a compressive strength at 10% deformation of 400 kPa and increased plate sizes to increase the installation speed. In addition, the increased dimensions of the slabs make it possible to reduce the number of joints and, consequently, increase the uniformity of the layer.

The nuances of installing extruded polystyrene foam when insulating the foundation

The insulation of the EPPS foundation, depending on its design, should be divided into a number of successive steps:

• Foundation preparation. When insulating the EPPS of the strip foundation, the walls must be smooth, cleaned of dirt and concrete layers. If necessary, we remove irregularities and cover up sinks, chips, etc. cement-sand mortar.

• The choice of the method of fastening the EPS. To fix the insulation, we use polymer-cement mixtures or, to speed up installation, special polyurethane adhesive foam.

• Adhesive foam is applied in a strip, about 3 cm thick around the entire perimeter of the plate, as well as one strip in the center of the insulation.

• The indentation of the adhesive foam strip from the edge of the plate is at least 2 cm.

• Before installing the plate, wait 5-10 minutes and only then glue it to the foundation wall.

• The gaps between the plates (if they exceed 2 mm) are foamed.

• If mechanical fixation of thermal insulation is provided, then we calculate the number of dowels as follows - for fixing 1 sq. m of thermal insulation on the central part of the foundation requires 5 pcs. fasteners. We fix EPPS on the corner parts of the foundation at the rate of: 6-8 dowels per 1 sq. m.

• When insulating the soles of a strip foundation or a monolithic slab, EPS is laid freely on a prepared base (usually on a compacted sand cushion). In this case, it is enough to foam the seams with glue-foam and, if necessary, fasten adjacent thermal insulation boards together. To do this, you can use a nail plate.

In this case, special fasteners can be used, which are a spike with teeth for fixing in the material and a flat area with an adhesive layer.

Together with such fasteners, gluing is carried out on an adhesive foam for polystyrene foam or on a special adhesive mastic that does not contain solvents. If necessary, the seams are sealed with mounting or adhesive foam.

The layout of the XPS plates during the construction of the UWB is as follows. The first layer is laid on a prepared base - a compacted sand cushion - with a gap between the seams relative to neighboring plates. The side elements are "L" - blocks, which are two XPS plates connected perpendicular to each other.

As a rule, such elements are made by setting the formwork, but ready-made elements that do not require the use of formwork can be used. Such "L" - blocks can be manufactured in the factory, or you can assemble it yourself at the work site. For this, a special corner fastener has been developed, which consists of corners and screws, and which is mounted at a distance of 300 mm from each other. All elements of corner fasteners are made of high-strength polyamide, which eliminates the formation of cold bridges.

Summarizing

In addition to increasing the energy efficiency of the foundation, EPPS insulation increases its service life, because waterproofing is reliably protected by durable material from various mechanical influences. By choosing the option of fixed formwork made of extruded polystyrene foam, you can significantly speed up and simplify all work on the construction of the foundation, because. there will be no need to assemble and further dismantle the wooden formwork, which means that the time and money of the developer are saved.