Features of insulation of a monolithic foundation slab? Insulation of the foundation slab with polystyrene foam, insulation, how to insulate? Do I need insulation under the slab foundation

Laying a shallow slab foundation in the construction of small buildings gives quite tangible savings in materials and financial resources. However, seasonal freezing of soils leads to movement and uneven lifting and settlement of the laid slab, resulting in its deformation with subsequent destruction of the entire structure. To avoid such risks, warming the slab foundation by laying horizontal thermal insulation will help to cut off the zone of frost heaving of soils under the structure.

Thermal insulation materials and methods of foundation insulation

A monolithic slab foundation finds its priority application in the construction of one to three storey houses. It is a reinforced concrete rigidly reinforced structure, which allows to perceive large external loads along the entire bearing plane of the slab without its deformation. Since the depth of laying such a foundation is higher than the level of soil freezing, the forces of frost heaving of the soil have to be compensated for by insulating the foundation slab with heat-insulating materials even at the stage of construction. The heater must meet several basic requirements:

• not be subjected to deformation under pressure;
• be resistant to moisture;
• have high heat-saving characteristics.

Previously used for such work mineral wool does not meet modern construction requirements due to insufficient rigidity of its structure, high water absorption and relatively low thermal insulation qualities. The latest production technologies in the manufacture of thermal insulation materials provide wide opportunity their choice. Depending on the method of insulation of a monolithic foundation slab, the most popular are:

• polyurethane foam;
• Styrofoam;
• extruded polystyrene foam.

These synthetic polymer foams provide reliable protection soles monolithic slab from freezing. In addition, for shallow foundations, a foundation is widely used, called an insulated Swedish slab, which is the best suited for heaving soils. Choosing the right insulation for a monolithic foundation will help short review properties of materials and methods of installation.

Polyurethane foam and its application

The main feature of this heat-insulating material is its dense closed cellular structure filled with inert gases by 85-90% and providing its low thermal conductivity. For insulation of foundations, the material can be used both in the form of finished sheets, and in the form of liquid self-foaming two-component compositions, inflated by spraying.

Applying liquid polyurethane foam to concrete screed under the prepared foundation slab compares favorably with the use of similar sheet materials.

1. High adhesion provides strong adhesion to the surface without leaving gaps or crevices. But slab polyurethane foam requires pre-treatment of concrete with special compounds for reliable bonding.
2. Polymerizing, the material forms a seamless coating that does not allow moisture to pass through. When using sheet polyurethane foam, additional waterproofing is required.
3. The composition is sprayed in 2-3 layers, which makes it possible to form any thickness of thermal insulation.

In addition, the environmental friendliness of the insulating material allows it to be used to insulate the finished foundation even indoors. But the main disadvantage in the use of polyurethane foam is the high cost of the components of the sprayed insulation and the inaccessibility of special equipment for work at home.

Styrofoam and extruded polystyrene foam

Extruded polystyrene foam has received wide application in the insulation of a monolithic foundation slab due, first of all, to its affordability. In fact, this is the same foam, but the difference in manufacturing technologies determined them. various properties and thermal insulation characteristics.

The main advantage of extruded polystyrene foam is that with a small specific gravity it has high compressive strength. This property allows it to withstand significant static loads without being deformed, and the porous structure of gas-filled closed cells determines its low thermal conductivity.

The undoubted advantage over polystyrene is the ability of extruded polystyrene foam to be minimally saturated with moisture, practically not letting it through. Styrofoam, due to its structure, has high water absorption, due to which it quickly loses its heat-insulating properties and becomes unusable, therefore its use as a heater for a foundation slab is undesirable.

Features of insulation of the slab foundation with polystyrene foam

Extruded polystyrene foam (EPS) is produced in the form of finished sheet material under different brands and, accordingly, of various thicknesses. For reliable insulation of the foundation slab, it is necessary to first make a calculation by determining the desired thickness, taking into account the density of a particular grade of XPS, the thermal resistance of the concrete slab being laid, as well as the climatic region. It is better to leave such a task to specialists or use the instructions of SNiP on building heat engineering and thermal protection of buildings.

The calculation of the thickness of heat-insulating materials when insulating a slab foundation is a fundamental factor in the construction of a high-quality foundation for a building under construction!

Styrofoam sheets are laid on waterproofing, which is used as bitumen roll materials. Sheets are glued end to end to each other on a surface preheated to the required temperature. On waterproofing materials that do not have a bituminous coating, an adhesive composition with special mastics is additionally applied. It should be borne in mind that various kinds of solvents should not be present in them, otherwise it will not work to avoid melting polystyrene foam sheets.

Some manufacturers produce XPS boards with a locking joint, which simplifies their installation and ensures minimal gaps between them. This design of the insulation helps to reduce heat losses and eliminates the so-called "cold bridges".

Before pouring a monolithic slab, the laid insulation will need to be protected from contact with the components of the liquid concrete mortar. When reinforcing the foundation with a connected iron frame, it will be enough to use polyethylene film 150-200 microns thick, which is laid in one layer overlapping with an overlap of 100-150 mm and fastened with double-sided tape. If welding is required for the installation of fittings, then it is recommended to protect the laid heat-insulating material cement-sand screed or low quality concrete.

The device of the foundation "insulated Swedish plate"

One of the fairly common options for insulating a shallow slab foundation is the method of combining building communications systems in an arranged monolithic structure. Heating, water supply and sewerage pipes passing through the slab additionally warm up the slab and soil, preventing them from uneven deformations. Such structures are indispensable on complex heaving soils, as well as on peat bogs with a high moisture content.

To exclude direct contact with the ground, additional insulation of the "Swedish plate" is carried out using sheet extruded polystyrene foam. Thus, a decrease in the thickness of concrete in the foundation monolith is achieved by almost 2 times.

The slab foundation technology according to the “insulated Swedish slab” type consists of several stages:

• clearing a shallow pit;
• geotextile linings;
• sand padding, followed by layer-by-layer tamping;
• insulation installation;
• knitting of the reinforcing cage under the entire area of ​​​​the slab;
• installation of communication pipes;
• pouring the prepared area with concrete.

The main advantage of this method of insulation is the combination of technological operations for the installation of a slab foundation with the simultaneous laying of communications, which can significantly reduce construction time. In addition, the ease of erection of the structure does not require the involvement of heavy construction equipment on the site.

Careful observance of technological standards, as well as the rules and methods for insulating low-depth monolithic slabs in various climatic zones, makes it possible to build foundations for low-rise buildings on almost any soil.

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 correct operation this type of foundation requires its protection from freezing. Insulation of a monolithic foundation slab:

• prevents the destruction of concrete from temperature differences;
• promotes warm floor 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. IN 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 help 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 installed in concrete, following works:

• 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 device 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 is shaped like a ball, which results in a better enveloping 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 design features buildings and construction sites. Choosing the optimal solution is based on the data of the heat engineering calculation and comparison of the estimated cost.

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.

Various foundation designs different ways insulation. Tape deep - only vertical walls near the surface of the earth are insulated, tape shallow - walls and soles. 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 polystyrene foam (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. So, external insulation is the most the best option for all 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 winter time years, 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 designs foundations of the house.

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 high level ground water. 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 cracking.

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 high consumption 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:

• concrete slab performs the function of the floor of the first floor, this 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 extends the life of the structure.

Advantages of slab thermal insulation

As thermal insulation material used polystyrene foam, polystyrene foam, polyurethane foam. 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

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 to be 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 erection 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 design stage, 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 strips. 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 stripes. 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:

• Tighter pipe laying results in more high temperatures space heating.
• 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 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 repair work. 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.
• Temperature stabilization during indoor areas 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 it 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 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 whole line 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. He keeps his thermal insulation properties even in cold regions. Advantages of extruded polystyrene foam:

• high strength;
• long term services;
• reliable thermal insulation properties.

It is most often used when it is 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.

Most effective method insulation of the foundation with the help of this material is its use 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 ordinary person after a relatively small 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 can create 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.
• Providing comfortable temperature conditions produced 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 wool 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. The ideal foundation that combines all these qualities are monolithic foundation slabs that can be built on various types 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 save money 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. Maximize the time beneficial use supporting structure, as it ceases to be adversely affected by moisture and low temperatures.
5. Insulated base plate prevents condensation on the internal walls premises.
6. Maximizes service life waterproofing materials, which are involved in the construction of slab foundation structures.

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. Components included in chemical reaction, already on concrete surfaces form a strong foam that 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 in 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. He 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 insulating 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 that case when polystyrene panels will be stacked with inner sides walls, the developer will be able to significantly improve the indoor climate, 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 will be ideal option for any building projects.

External insulation of the foundation with polystyrene foam or foam plastic is possible only on early stages 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 installation 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. Are being laid engineering Communication such as plumbing 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 roll 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 concrete base and after complete drying continue construction works.
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.

Almost 80% of the territory of our country falls on the zone of heaving soils, which are dangerous for the foundation slab and other types of foundations for buildings and structures. Such soils, when frozen, can significantly increase in volume, which leads to a rise in its surface - frost heaving.

How to insulate the base plate?

Insulation of the foundation slab allows you to cut off the zone of frost heaving, which means avoiding its cracking. In addition, heating bills are reduced. Another plus can be considered the fact that condensation does not form on the walls, which means that mold does not appear. Carrying out work on thermal insulation has a beneficial effect on the operational properties of the entire building, increases its durability.

When choosing a material for insulating a foundation slab, the following performance characteristics should be taken into account:

• high level of mechanical compressive strength;
• minimum rate of water absorption;
• low thermal conductivity.

Such familiar insulation as mineral wool is not suitable for these purposes, since it absorbs water well and shrinks when backfilled with soil. Meets all requirements and is very easy to use expanded polystyrene. Another insulation under the foundation slab, which has the necessary performance, is foam glass, but its use will cost much more.

Warming of the foundation slab can occur not only from the outside, but also from the inside. Experts believe that external thermal insulation is much more effective and allows you to solve many problems to improve the indoor climate and increase the durability of the building. However, insulation from the outside is not always possible, mainly due to the high labor intensity, so these works are best done at the construction stage.

However, internal thermal insulation also gives its results: the room becomes warmer, the microclimate normalizes, heat does not leak out. It should also be noted the simplicity of such work.

Insulation of the foundation slab with expanded polystyrene

Extruded polystyrene foam is considered to be a fairly effective and simple way to insulate foundation slabs. This material has a closed-cell structure, which differs from conventional foam plastic, in which, after 2-3 years of operation, the structure will be destroyed and it will turn into a pile of balls.

Extruded polystyrene has the following properties:

• resistance to moisture and aggressive chemical compounds;
• does not age or change operational properties;
• ecological cleanliness;
• affordable price, etc.

For thermal insulation, expanded polystyrene is used in the form of special plates. They must have a compressive strength of at least 200 kPa for private buildings, 250 kPa for industrial facilities and high-rise residential construction.

To insulate the vertical part of the foundation slab from the outside, it is necessary to perform preparatory operations:

• if the foundation was covered with soil, then it is necessary to remove all the earth along the side surface to the depth of soil freezing;
• apply to all work surface layer of insulation.

Installation of insulation boards

When bituminous roll material is used as waterproofing, it is enough to heat it up at several points and press the polystyrene plate. It is very important to calculate the pressing force, since it is possible to push through the surface of the insulation and the product will become unusable.

If other types of bitumen or bitumen-polymer materials are used, then a special mastic is applied to the expanded polystyrene under the foundation slab in the form of stripes or dots and applied in the right place. For competent thermal insulation, the plates are staggered. Metal fasteners can disrupt waterproofing, so experts do not recommend using them when insulating foundation slabs.

It is rather difficult and time-consuming to carry out sufficiently large volumes of work that require not only skill, but also knowledge, as well as experience in their implementation. If you live in Moscow or the Moscow region, then by contacting the construction company "Proekt", you can save yourself from this monotonous and effort-consuming work, and get high-quality and quickly performed insulation of foundation slabs at a low price.

Base insulation

It is possible to carry out insulation under the foundation slab only in the process of its installation, which means it needs to be planned at the stage of project development. Thermal insulation products made of extruded polystyrene foam are laid on the insulation layer.

To protect the insulation under the foundation slab from the ingress of liquid components of concrete, a polyethylene film is laid on it in one layer, which should have a thickness of 150-200 microns. Such protection will be enough if it is done by knitting. If welding is used, then it is necessary to create a protective screed, which can be made of low-grade concrete, or a solution of sand and cement. In this case, polyethylene is laid using double-sided tape with an overlap of 150 mm.

Warm base plate

The construction of a warm foundation slab begins with the digging of a pit, on the bottom of which sand is first laid, which must be compacted and communication pipes laid in it. Then lay a layer of gravel and thermal insulation in two layers. Fittings are installed on the insulation, on which pipes heating the floor are placed, and they should not intersect with each other. It remains only to fill this multilayer structure with concrete, the thickness of which will be 10 cm.

By analogy, our specialists have developed their own concept of a warm foundation slab. In this case, extruded polystyrene foam is laid on a sand bed. At the same time, the method of placing the insulation depends on the design of the building and the tasks of heat saving. Next, fittings are laid and right inside reinforcing mesh lay pipes for a water-heated floor. Then they fill everything with concrete.

Cope with any of the above options for the construction of a warm foundation slab, only specialists with sufficient qualifications, experience and sound knowledge can cope. All these criteria are met by our employees. Contact us and you will be able to become the owner of the foundation, the parameters of which will meet all state standards, we will definitely take into account all the wishes of customers.

Insulation of a monolithic foundation slab is necessary in areas with cold climatic conditions. Such measures are required in order to protect the base from the harmful effects environment, preservation of warmth, coziness and comfortable living conditions in the house. One of the most common materials for insulation are polystyrene foam and polyurethane foam.

Insulation of the foundation of a monolithic type with polystyrene foam

Thermal insulation of base plates in this way is a relatively young type of modification of private houses. It began to be used in the 50s - 60s of the XX century. This type of insulation plate is durable and long service life. According to statistics, the popularity of polystyrene foam is steadily growing every day.

Strengthening monolithic slabs with expanded polystyrene has shown itself to be very good decision in the construction of houses, because their service life is more than 50 years. After carrying out various tests and checks, it became clear that the material does not change in any way over the entire period of operation.

From this it follows that the growing popularity and steady increase in the consumption of expanded polystyrene is a pattern. Over the past 20 years, its use has increased tenfold. Main consumers this material are Europe and North America.

Extruded polystyrene foam for insulation of a monolithic base slab is a material that has a uniform structure consisting of closed cells. Due to the low density of the material, its thermal insulation properties increase. You should also know that expanded polystyrene has increased strength characteristics and is able to withstand fairly large loads.

Expanded polystyrene practically does not pass water and is not afraid of exposure to chemically aggressive environments. Thermal insulation with this material is made in regions with severe winters and very cold weather. Expanded polystyrene perfectly copes with repeated cycles of freezing and defrosting, while its performance does not change at all. Expanded polystyrene is usually sold in the form of plates.

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Why polystyrene and not another material?

1. A platform for the foundation is marked.
2. The layer of soil is removed from above. The depth depends on the construction project. When taking out the soil, you must try to make the bottom as even as possible. To do this, the last 0.2 - 0.3 m is taken out manually. A layer of sand is poured onto the prepared site and then rammed.
3. Temporary formwork is installed, concrete base is being prepared. The formwork is poured with a small layer of concrete. Base reinforcement is not required.
4. After the concrete has hardened, the laying of polystyrene foam plates begins, while it is necessary to combine the mounting grooves and try not to leave large gaps.
5. A polyethylene film is placed on the laid layer of insulation. The joints are glued with adhesive tape. Polyethylene creates a layer of waterproofing. In addition, the film prevents leakage of concrete between the joints of the insulation boards.
6. The construction of formwork and reinforcement cage is in progress. Concrete is being poured.
7. After complete drying, the formwork is removed.
8. The side walls are additionally insulated with expanded polystyrene.

A few tips:

• work starts from any corner of the foundation;
• slabs must be laid from the bottom up with a shift in the rows, that is, something similar to brickwork should be obtained;
• at a height approximately equal to the width of the plate, pull the rope. The horizontal tension is checked using the building level;
• the first row of the heat-insulating layer is laid. This is done so that subsequent rows of plates do not diverge, otherwise all the insulation will simply become useless.

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How to properly mount polystyrene foam boards on the walls?

The foundation wall is covered with straightened mastic. Then expanded polystyrene is attached to it and tightly pressed. All plates of a row are mounted in a similar way.

When conducting work, it is necessary to carefully monitor the connection of adjacent plates. It should be clear, without cracks and be in the castle.

The joints on the crests of the locks are cut off in the corners. If necessary, the joints are additionally filled with foam.

As the high rows are laid, the underlying ones are covered with soil. Such actions facilitate the work and help to press the material.

Slabs located below ground level are glued only to the mastic.

This is necessary to prevent damage to the waterproofing.

Insulation located above the ground can be further strengthened with dowel-nails (umbrellas). All this can be easily done with your own hands, you just need to be very careful. To fix the base on the walls, holes are drilled with a puncher. Umbrellas are fixed in the center and at the junctions of adjacent plates.

The foundation, insulated with polystyrene foam, is so popular for the following reasons:

• using this technology, you can save up to 40% of money;
• reduction of heat loss reaches 20%;
• the waterproofing layer of the foundation will last 2 times longer;
• expanded polystyrene guarantees quality and long service life;
• the plates reliably protect the waterproofing layer, providing drainage of accumulated groundwater.

From the above, it becomes clear that, insulated with polystyrene foam, it will serve for a long time, and the house will be cozy, comfortable and warm. In addition, the material is absolutely safe from an environmental point of view and has a low cost, which clearly inclines the choice in its direction when long-term construction is ahead.