How to insulate a slab foundation with polystyrene foam? What is the insulation of a slab foundation? What is the density of insulation under the foundation slab?

Laying shallow slab foundation When constructing small buildings, it provides quite significant savings in materials and financial resources. However, seasonal freezing of the soil leads to movement and uneven rise and settlement of the laid slab, resulting in its deformation and subsequent destruction of the entire structure. Insulating the slab foundation by laying horizontal thermal insulation will help to avoid such risks, allowing you to cut off the zone of frost heaving of the soil under the structure.

Thermal insulation materials and methods of foundation insulation

Monolithic slab foundations find their priority application in the construction of one to three-story houses. It is a reinforced concrete rigidly reinforced structure that allows it to accommodate large external loads along the entire bearing plane of the slab without deformation. Since the depth of such a foundation is higher than the level of soil freezing, the forces of frost heaving of the soil must be compensated for by insulation foundation slab thermal insulation materials at the construction stage. The insulation must meet several basic requirements:

not be subject 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. Newest technologies production in the manufacture of thermal insulation materials provide a wide range of choices. 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 the soles of the monolithic slab from freezing. In addition, for shallow foundations, a foundation called an insulated Swedish slab is widely used, which is ideally suited for heaving soils. Select suitable insulation for monolithic foundation will help short review properties of materials and installation methods.

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 ensuring its low thermal conductivity. To insulate 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.

Application liquid composition polyurethane foam on a concrete screed under the foundation slab being prepared compares favorably with the use of similar sheet materials.

High adhesion ensures strong adhesion to the surface without leaving gaps or cracks. But slab polyurethane foam requires pre-treatment of concrete special compounds for reliable bonding.
When polymerized, the material forms a seamless coating that does not allow moisture to pass through. When using sheet polyurethane foam additional waterproofing is required.
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 a finished foundation even indoors. But the main disadvantage of using polyurethane foam is the high cost of the components of the sprayed insulation and the unavailability of special equipment for doing work at home.

Polystyrene foam and extruded polystyrene foam

Extruded polystyrene foam is widely used for insulating a monolithic foundation slab due, first of all, to its affordability. Essentially, this is the same foam plastic, but the difference in manufacturing technologies determined their different properties and thermal insulation characteristics.

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

An undoubted advantage over polystyrene foam is the ability of extruded polystyrene foam to be minimally saturated with moisture, practically without allowing it to pass through. Polystyrene foam, due to its structure, has high water absorption, which is why it quickly loses its heat-insulating properties and becomes unusable, so its use as insulation for a foundation slab is undesirable.

Features of insulating a slab foundation with polystyrene foam

Extruded polystyrene foam (EPS) is produced in the form of finished sheet material under different trademarks and, accordingly, different thicknesses. To reliably insulate the foundation slab, it is necessary to first make a calculation by determining required thickness taking into account the density of a particular brand of EPS, the thermal resistance of the concrete slab being laid, as well as the climatic region. It is better to leave this task to specialists or use the instructions of SNiP on construction heating engineering and thermal protection of buildings.

Calculating the thickness of thermal insulation materials when insulating a slab foundation is a fundamental factor in constructing a high-quality foundation for a building under construction!

Laying of expanded polystyrene sheets is carried out on waterproofing, which is used as bitumen roll materials. The sheets are glued end-to-end to each other on a surface preheated to the required temperature. On waterproofing materials, which do not have a bitumen coating, are additionally applied adhesive composition with special mastics. It should be taken into account that they should not contain various types of solvents, otherwise it will not be possible to avoid melting the polystyrene foam sheets.

Some manufacturers produce EPS boards that have a locking connection, which simplifies their installation and ensures minimal gaps between them. This insulation design helps 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 solution. When reinforcing the foundation with a bonded iron frame, it will be sufficient to use a polyethylene film with a thickness of 150-200 microns, which is laid in one overlapping layer with an overlap of 100-150 mm and fastened double-sided tape. If the installation of fittings requires welding work, then protect the laid heat insulating material recommended cement-sand screed or low-quality concrete.

Construction of the foundation “insulated Swedish slab”

One of the fairly common options for insulating a shallow slab foundation is the method of combining monolithic design building communication systems. Heating, water supply and sewage pipes passing through the slab additionally heat the slab and soil, preventing them from undergoing uneven deformations. Such structures are indispensable on complex heaving soils, as well as on peat bogs with a high moisture content.

To avoid direct contact with the ground, additional insulation“Swedish plate” using sheet extruded polystyrene foam. In this way, the thickness of concrete in the foundation monolith is reduced by almost 2 times.

The technology for constructing a slab foundation using the “insulated Swedish slab” type consists of several stages:

clearing a shallow pit;
laying of geotextile fabric;
adding a sand cushion followed by layer-by-layer compaction;
laying insulation;
tying the reinforcement cage over the entire area of the slab;
installation of communication pipes;
pouring concrete into the prepared area.

The main advantage of this insulation method is the combination of technological operations for installing 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 at the site.

Careful adherence to technological standards, as well as rules and methods for insulating shallow monolithic slabs in various climatic zones, allows the construction of foundations for low-rise buildings on almost any soil.

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 the material that can be useful to everyone.

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

Why is it necessary to insulate the foundation?
What to look for when choosing a material for foundation insulation.
How to properly secure extruded polystyrene foam to the foundation.
What tool is needed for the job?

Why is it necessary to insulate the foundation?

The foundation is called underground part structures that transfer the load from overlying structures to the prepared soil foundation. Foundations are of the following types:

Slab, shallow, with spatial reinforcement. This gives the structure rigidity and allows it to absorb loads arising from uneven soil movement without internal deformation.

Tape - laid below the freezing depth, etc. MZLF - shallow strip foundation, with a base depth above the calculated level of seasonal soil freezing.

. Insulated Swedish Plate. This foundation is a monolithic concrete slab, mounted on a base insulated with extruded polystyrene foam. A water underfloor heating system and all utilities are integrated into the foundation.

This type of foundation is considered the most technologically advanced and energy efficient. One system combines the foundation and a low-temperature heating system, eliminating the formation of local overheated zones and providing comfortable radiant heat. In addition, the foundation is not exposed to the forces of frost heaving, because Anti-heaving measures have been carried out. Namely, the 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 the total heat loss of the building occurs through the foundation.

Kogut Andrey TechnoNIKOL technical specialist

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

In some cases, it is enough to insulate the floor and base, but when organizing the exploited basement thermal insulation of foundation walls is 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 heaving 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 allow water to pass through them well, 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, including destruction of the foundation. If you leave the foundation uninsulated, the heat flow will go down and warm the soil, protecting it from freezing. However, the house may not be heated constantly, and in this case the soil heaves. 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, summarizing all of the above, we conclude: the foundation needs to be insulated. Not every insulation is suitable for this, but only material that can work in aggressive conditions external environment. Those. thermal insulation designed to be “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 the overlying structures.

Kogut Andrey

Extruded polystyrene foam (EPS) has a low thermal conductivity coefficient 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 – no 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 EPS in loaded structures (foundations) and ensures the stability of the thermal insulation thickness under load.

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

Purpose of the building (residential, administrative, industrial, etc.).
The insulation must provide the required heat transfer resistance for a given 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 buildings." For different regions, the thickness of thermal insulation may vary, depending on climatic conditions. It should also be taken into account that increasing the thickness of thermal insulation increases the energy efficiency of the building and, therefore, leads to lower heating costs.

Choosing specifications thermal insulation, we are guided by the following principles:

When thermally insulating a strip foundation, when only the vertical wall is insulated, increased strength of the material is not required, because in this case, the EPS takes up loads only from the backfill soil. Therefore, for shallow foundations, brands of extruded polystyrene foam with a compressive strength (at 10% linear deformation) of 150-250 kPa are suitable.
When laying EPS slabs under the base of the foundation or under the slab, the loads on it increase significantly, and accordingly, the requirements for its strength increase. IN in this case It is recommended to use thermal insulation boards with a compressive strength of 250 - 400 kPa.
A material has been developed specifically for USP with a compressive strength at 10% deformation of 400 kPa and increased slab sizes to increase installation speed. In addition, the increased dimensions of the slabs make it possible to reduce the number of seams and, accordingly, increase the uniformity of the layer.

The nuances of installing extruded polystyrene foam when insulating the foundation

Insulation of the EPPS foundation, depending on its design, should be divided into a number of sequential steps:

Preparing the base. When insulating an EPS strip foundation, the walls must be smooth, free of dirt and concrete deposits. If necessary, we remove uneven surfaces and cover up sinkholes, chips, etc. cement-sand mortar.

Choosing a method of fastening EPS. To attach the insulation, we use polymer-cement mixtures or, to speed up installation, special polyurethane adhesive foam.

Adhesive foam is applied in a strip approximately 3 cm thick along the entire perimeter of the slab, as well as in one strip in the center of the insulation.

The distance of the adhesive foam strip from the edge of the slab is at least 2 cm.

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

We foam the gaps between the plates (if they exceed 2 mm).

If mechanical fixation of thermal insulation is provided, then the number of dowels is calculated as follows - for fastening 1 sq. m of thermal insulation on the central part of the foundation requires 5 pieces. fasteners We fix the EPS on the corner parts of the foundation at the rate of 6-8 dowels per 1 sq. m.

When insulating the base of a strip foundation or monolithic slab, EPS is laid loosely on a prepared base (usually on a compacted sand bed). In this case, it is enough to foam the seams with adhesive foam and, if necessary, fasten adjacent thermal insulation boards together. You can use a nail plate for this.

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

Together with similar fasteners, gluing is done using adhesive foam for polystyrene foam or to a special adhesive mastic that does not contain solvents. If necessary, the seams are sealed with mounting or adhesive foam.

The layout of EPS slabs during the construction of USHP is carried out as follows. We lay the first layer on the prepared base - a compacted sand cushion - with the seams staggered relative to the adjacent slabs. The side elements are “L” blocks, which are two EPS slabs connected perpendicular to each other.

As a rule, such elements are made by installing formwork, but you can use ready-made elements that do not require the use of formwork. Such “L” blocks can be manufactured in a factory, or they can be assembled independently at the work site. For this purpose, a special corner fastener has been developed, which consists of corners and screws, and which are 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, EPS insulation increases its service life, because the waterproofing is reliably protected by durable material from various mechanical influences. Selecting an option permanent 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 disassemble wooden formwork, which means the developer will save time and money.

To begin with, the location of the foundation for the building is marked on the building site.
The top layer of continental soil must be removed to the depth of laying the foundation slab, the bottom of the excavation must be as smooth as possible.
The prepared area is filled with coarse sand, which must be compacted using vibrating rammers. A small layer of concrete is poured over the layer of sand, for which it is exposed.
After hardening concrete screed, lay out insulation from polystyrene foam boards, making sure that the mounting grooves match as much as possible. Large gaps should not be allowed between the insulation boards.
A layer of polyethylene film is laid on top of the laid polystyrene slabs, which is glued together using special tape.
Construction formwork is being erected for pouring the slab base into which it is mounted spatial frame from reinforcement with a diameter of 10 mm. Concrete is poured from the corner of the slab foundation, evenly leveled and compacted using a vibrator.
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 has gained up to 70% strength.
The side walls of the foundation slab are additionally insulated with expanded polystyrene slabs.

An insulated monolithic slab will last long years without structural damage from exposure to unfavorable factors.

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

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

The “Swedish slab” technology combines the construction of an insulated monolithic foundation slab and the possibility of laying communications, including a water floor heating system. A complex approach allows you to quickly obtain an insulated base with built-in engineering systems and a flat floor, ready for laying tiles, laminate or other covering.

The main advantages of an insulated Swedish stove:

The construction of the foundation and the laying of communications are carried out during one technological operation, which allows to reduce construction time.

The ground surface of the foundation slab is ready for laying flooring;

The PENOPLEX FOUNDATION® thermal insulation layer, about 20 cm thick, reliably protects against heat loss, which means a significant reduction in home heating costs 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 frost heaving problems in foundation soils;

Laying the foundation does not require heavy equipment or special engineering skills.

Installation features

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

The design of the Swedish slab involves the transfer of all loads from the structure (its own weight, operational loads, snow, etc.) to the insulation layer, which is why to the used thermal insulation material high demands on strength are imposed. Most rational option Applications in this design are thermal insulation boards PENOPLEX FOUNDATION®, which have practically zero water absorption and high compressive strength.

Instructions for use:

Step 1. Removing the top layer of soil (usually about 30-40 cm);

Step 2. Compacting sand and gravel preparation (coarse sand, crushed stone);

Step 3. Installation of drainage around the perimeter of the structure and pipes engineering communications;

Step 4. Laying side elements and PENOPLEX FOUNDATION® slabs in the base;

Step 5. Installation of the reinforcement 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 the monolithic slab with concrete mixture.

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

When laying heating pipes, the following rules are followed:

The higher thermal power of heated floors is achieved by denser pipe laying. And vice versa, that is, along the outer walls the heating pipes should be laid more densely than in the middle of the room.
It makes no sense to lay pipes more densely than every 10 cm. More dense laying leads to a significant overuse of pipes, while the heat flow remains practically unchanged. In addition, a thermal bridge effect may occur when the coolant supply temperature becomes equal to the processing temperature.
The distance between heating pipes should not be more than 25 cm to ensure uniform temperature distribution over the floor surface. To prevent the “temperature zebra” from being perceived by a person’s foot, the maximum temperature difference along the length of the foot should not exceed 4°C.
The distance between heating pipes and external 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.
Pipes cannot be laid at the junction of monolithic slabs. In such cases, it is necessary to place two separate contours along different sides from the junction. And pipes crossing the joint must be laid in metal sleeves 30 cm long.

The foundation - insulated Swedish slab (USP) refers to slab foundations.

A distinctive feature is that this foundation, among many, is a more progressive and original type of foundation, which, in principle, meets the most modern requirements for energy efficiency of the house, and, in principle, the construction of the foundation as a whole. USP foundation for post-Soviet times is a relatively young option.

For the first time, information about the foundation of an insulated Swedish slab appeared on construction forums 10 - 15 years ago. There it was very actively discussed. But a number of points that are definitely worth knowing when using such foundations were omitted. Mostly there were odes of praise addressed to this foundation.

Pros and cons of USP

Advantages of USHP, like all slab foundations	Disadvantages of USHP and all slab foundations
Loads are transmitted fairly evenly, since the slab, to a greater extent than just a tape, distributes the loads and transfers them evenly to the base in the form of soil under the foundation.	They are exposed to the risks of heaving and uneven settlement as they are located in an unfavorable soil zone with low bearing capacity, as well as in the freezing zone, because they don't go deep load-bearing basis to the freezing depth.
Solidity. All monolithic work on pouring the foundation with concrete is carried out in one step. When pouring, a concrete pump and a deep vibrator must be used. The result is a monolithic layer of concrete, which is very important for the foundation.	There are nuances regarding the arrangement of communications and the topography of the site
Small amounts of work. Unlike monolithic strip foundations, there is much less work on USP, both earthworks and the tying of reinforcement, acceptance of concrete, and installation of formwork.

Differences from a conventional slab foundation:

When installing USHP, a large volume of insulation is used. It is used around the perimeter of the foundation and, as a rule, not to the depth of freezing, but to the depth of the foundation, this is usually 600 mm, which corresponds to standard size sheet of extruded polystyrene foam.

Also, insulation is used directly under the slab and blind areas must be insulated.

This type of foundation, according to Dmitry Marchenko, is far from ideal. Marchenko believes that the choice of this type of foundation is more likely to refer to failed decisions than to rational decisions.

After this type of foundation was promoted on construction forums, it was actively picked up by manufacturers of polystyrene foam insulation materials and made technological maps and instructions for arranging these types of foundations. As a result, the topic of USP received even greater status as a professional solution for constructing the foundation of a private house. It is not without reason that these manufacturers became interested in this particular foundation technology - it uses very more quantity insulation and most of it is simply used irrationally, one could easily do without it.

Marchenko expresses the opinion that this technology is beneficial rather not for the owners of the future home, not for builders, it is beneficial specifically for manufacturers of polystyrene foam.

Dmitry Marchenko studied this foundation in detail and did not see anyone else interested in this foundation other than manufacturers of extruded polystyrene foam.

How rational is the foundation of USHP?
On many sites promoting this foundation you can see a large list of its advantages. According to Dmitry Marchenko, most of these advantages are simply far-fetched and in reality have no basis in evidence.

Reality and advertising using USP

ADVANTAGES INDICATED FOR USHP	VALIDITY OF THE USHP FOUNDATION
USHP is a fairly cheap type of foundation, because... A much smaller volume of reinforcement and concrete is used, and a much smaller volume of excavation and monolithic work is used.	For comparison, a strip monolithic foundation is usually taken. Indeed, USHP uses less concrete - the slab thickness is only 100 mm and less reinforcement - the reinforcement is knitted in just one layer. But many years of practice show that one layer of reinforcement is not enough. You need 2 layers of reinforcement and they must be tied with clamps with a certain step, additional “pawns” must be made from the reinforcement. But this is not included in the proposed USP technology. Therefore, the main disadvantage of this foundation is a weak slab. Also, this foundation uses a lot of high-quality insulation. And any insulation will not work here; you need high-quality and expensive extruded polystyrene foam. And for example, for a house with a slab measuring 10 x 10 meters, 18 cubic meters of insulation will be required. And the foundation with so much insulation becomes simply “golden” in cost. In terms of price, it covers even a monolithic strip foundation. Therefore, such an advantage low price- is fundamentally wrong. Also, installing a sand cushion is not the cheapest pleasure. First you need to choose the native soil, then bring in sand. The sand must be moistened layer by layer and compacted; this all must be compulsorily observed. These are additional costs.
USHP is suitable for building houses on any soil, both heaving and non-heaving, subsidence and non-subsidence, etc.
This foundation distributes loads evenly.
Suitable for all types of houses - wooden, brick, lightweight concrete, etc.

The thickness of the sand cushion is 300-400 mm, so high-quality sand compaction is very rarely achieved. Very often builders neglect this.

For example, they do not do it layer by layer or do not spill it enough, or, on the contrary, fill it with sand and then it cannot be compacted properly. And even if all this is done efficiently, there will still be places of uneven compaction throughout the entire area of the sand cushion. As a result, this will lead to the fact that the base of the sand cushion under the house, and it will not be local, but common to all the slabs, may turn out to be uneven and lead to uneven shrinkage of the foundation. uneven shrinkage of the foundation, in turn, will lead to possible cracking of the foundation, and then reinforcement in one layer will be extremely insufficient for the foundation to maintain its geometry and not crack, which will result in the appearance of a crack in the load-bearing structures of the house. Thus, the sand cushion affects the stability of the entire house.

Another disadvantage is the possible deformation of the EPS itself. Despite the fact that the manufacturer claims high technical and operational characteristics of its products, that the material has very high compression properties, practice shows that under heavy loads it works, at least, not as stated in its characteristics. This means that deformations of the material are possible, which will lead to uneven shrinkage of the foundation. Extruded polystyrene foam directly under the foundation slab receives huge loads in the form of pressure from the house, which means its durability is questionable. Despite the fact that manufacturers claim ideal qualities, there are very few stories of using EPS in this way, there is no information on its caking over 10-15-20 years, and this calls into question the integrity of the entire house. There is no certainty that a person will want to risk his investment in a house in order to experiment on himself how conscientious the EC manufacturer was.

The disadvantage of this foundation, like other slab foundations, is the low base. Usually it is 10 cm already from the level of the blind area and the wall structures of the house are in very close proximity to the ground, which means they will be in the zone high humidity, which is a very vulnerable moment for our climate. A base with a height of 10 cm is not enough for our climate; in our climatic conditions, the base should have a height of 50-60 cm. This will provide sufficient distance from the ground for wall structures and remove any moisture and snow from them. Like other types of slab foundations, this foundation will require flat area and the absence of any slopes from any side towards the house, because any rain or melt water will wet the side parts of the foundation base and these places will heave unevenly, undermine the blind area, and may even lead to the lifting of some part of the foundation, and if the foundation plays unevenly, deformations may occur on the foundation or on the wall structures.

Majority technological maps or instructions for arranging this foundation imply the installation of a drainage system. It must be installed in a warm zone of the earth, otherwise the drainage will most likely simply be torn apart by heaving in the first winter. It will fill with water and in winter, when the temperature is below zero, it will simply freeze and burst. But any drainage system has a tendency to silt, and in this case this system under the house will have a greater tendency, because Already at the stage of laying the foundation of the house, it will be exposed to possible risks of clogging from the workers; the vibrating plate will work. Of course, protection is provided in the form of geotextiles, but practice shows that there are joints and some shortcomings of the builders, as a result of which the drainage systems are flooded. There is a way out that partially solves the situation, they are building inspection hatches, through which drainage systems can be flushed under water pressure, but in most cases hidden drainage systems are not the most the best solution, especially if this is not done by drainage specialists, but by ordinary foundation builders. In such cases, very often missed important points, because if there is no practice, it cannot be replaced with information from the Internet. It’s even easier to lay drainage pipes not enough. You need to make a branch with a slope, you need to make a receiving well, install a drainage pump. This will result in an even greater increase in construction costs.

On the site you will have to allocate space for a drainage well, regularly maintain and monitor it, clean out the drainage system, which is likely to completely silt up in 5-10 years. And the maintainability of drainage systems in these places is simply impossible. Any excavation work in this place will simply lead to settlement of the foundation. This is another disadvantage to questions about the price of this foundation. At this point, we can basically say that this type of foundation is not profitable.

But its shortcomings don't end there.
Private houses are usually built outside the city, where there are large numbers of rodents, ants, etc. And insulation under the foundation for them perfect place for arranging burrows. The insulation will not be complete, and the pressure from the house will remain the same. Hence, deformations, subsidence of the insulation, and along with it subsidence of the foundation are possible. And within 10-5 years, the picture with the geometry of the foundation may deteriorate dramatically.
There is a solution that is partially used in the construction of any house, since it is always rational to insulate the blind area of the house, insulate the foundation to prevent freezing of the slab, to prevent frost from getting under the foundation, even a monolithic one, therefore, when installing insulation from EP, the right solution is always to install a protective mesh . But if you protect metal mesh the entire volume of insulation, then it is very expensive, and it is not a fact that ants will not be able to get into it.

As for heated floors when installing this foundation: The installation of underfloor heating pipes can already be carried out at the stage of its construction. The underfloor heating pipes are attached with clamps to the fittings, which are located at the bottom of the slab. And as a result, after pouring, you get a ready-made foundation in which the heated floor pipes are located, which means you will not need to use a classic system to install heated floors using insulation, when insulation is installed on the monolithic slab of the house, heated floor pipes are laid, a screed is made, and as a result you also get heated floors, but you pay extra for this work.

Floor screed, which is installed through heated floor pipes, has a relatively low density and, accordingly, heat capacity, compared to monolithic slab. This allows the underfloor heating pipes to relatively quickly warm up the screed layer and release heat into the room. If you look at the underfloor heating system in USHP, it is different from the classic screed. we get: the stove itself has a high density and a high heat capacity, which means that in order to heat this stove, the boiler must work much more. and you will have to pay more for it in order to warm up the entire volume of concrete and only then will it give off high-quality heat to the room. And if the thickness from the underfloor heating pipes to the final coating is 5-6 cm, then in the case of USP this distance increases by 2-2.5 times. And in order to warm up your house, you must warm up the stove itself for 1-2 days, and only then will some thermal effect begin from the heated floor pipes. This system is very slow to warm up and cool down. Therefore, if we compare the installation of heated floors, then the classic system is more advantageous, because it allows, at lower costs in heat energy, to quickly transfer this energy to the room.

Because this system directly connected to water, it may have problems with leaks. Construction workers may accidentally crush or damage a pipe, which may result in the need for repairs. In the case of the classical system, the screed is broken, the breakdown site is located and eliminated. Here the breakdown location is not difficult to find, because it will form a wet spot on the floor. and in the case of a monolithic slab, finding the location of the damage will be quite problematic; you will also have to make a lot of effort to get to the pipe, and the solidity of the supporting structure of the house will be damaged. And in the case of a screed for integrity load-bearing structures Finding and fixing the hole will have no effect.

Like all other slab foundations, this foundation requires a clear technological calculation, as well as a clear understanding and clear design engineering systems zero cycle already at the foundation stage. Those. If, when installing other types of foundations, you have the opportunity to think about moving the pipe outlets before installing the plumbing, then with this system you will not be able to move the already installed pipes anywhere. ,
If you are faced with the fact that you have pipes and sleeves coming out of your foundation slab, always protect them; covering them with something is an incomplete solution; the most proven solution is to make boxes out of wood. .
The technology is beneficial for manufacturers of extruded polystyrene foam.