Foundation insulated Swedish plate scheme. What is an insulated Swedish stove? Wiring of engineering communications and the creation of a shock-absorbing cushion

The Swedish plate is an insulated monolithic slab foundation of small depth. The main feature of this technology is that the entire base of the house is based on a layer of insulation (under the stove). Under warm home the soil does not freeze and does not heave. Such a foundation is suitable for any soil, at any depth of occurrence. ground water.
This technology is based on the basic principles of design and construction shallow foundations on heaving soils described in Organization standard (STO 36554501-012-2008), developed by the Research, Design and Survey and Design and Technology Institute of Foundations and Underground Structures (NIIOSP) named after. N.M. Gersevanova (FSUE NRC "Construction"), FSUE "Fundamentproekt", Moscow State University. M.V. Lomonosov (Faculty of Geology, Doctor of Technical Sciences L.N. Khrustalev) and the technical department of PENOPLEX SPb LLC.

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

The main advantages of the insulated Swedish plate:

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

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

The PENOPLEX® GEO thermal insulation layer, about 20 cm thick, reliably protects against heat loss, which means a significant reduction in the cost of heating the house and an increase in the efficiency of the "warm floor" system;

The soil under the insulated slab does not freeze, which minimizes the risk of problems with frost heaving of the base soils;

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

Mounting Features

To ensure the normal operation of the insulated Swedish slab (UShP) and to prevent frost heaving, it is necessary to provide for the installation of a groundwater drainage system (drainage system along the perimeter of the structure). An important role is also played by the device of non-porous preparation (pillow of coarse sand, gravel). If a combination of crushed stone and sand layers is used, it is necessary to provide for the separation of these layers with geotextiles (when the soil of a fine fraction is located above a larger one).

All necessary communications (water supply, electricity, sewerage, etc.) and inputs must be laid under the stove in advance.

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

Instructions for use:

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

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

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

Step 4. Laying of side elements and PENOPLEX® GEO boards at the base;

Step 5. Mounting the reinforcing cage on stands;

Step 6. Laying pipes for the floor heating system, connecting them to the collector and pumping air into them;

Step 7. Filling a monolithic slab with concrete mix.

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

When laying heating pipes, the following rules are followed:

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

More recently, when choosing a foundation for a residential building, the main criteria were the reliability, strength and durability of the structure. With the advent of new technologies, it became possible to take into account also the cost, as well as the functionality of the base. Today, for low-rise construction on sites with weak soils you can choose not only a columnar or pile foundation, but also a more technologically advanced insulated Swedish slab (UShP). The simplicity and accessibility of the technology allows you to get a monolithic, heated base with your own hands and at the same time not go beyond the budget.

Features of the insulated Swedish stove

The monolithic foundation foundation of the UWB was first tested on the Scandinavian Peninsula and for a long time was used mainly in the north-west of Europe. Today the situation has changed and the geography of using the Swedish foundation has expanded significantly, spreading also to the vast expanses of Russia.

When building an insulated Swedish slab, concrete alone is not enough - modern heat-insulating materials will be needed

As the name implies, this type of support structure is a reinforced concrete foundation slab laid on a layer of insulation. The design does not require much deepening, therefore it is perfect for construction on sites:

With high level groundwater;
with loose and loose soil;
with soils subject to heaving and shear.

A key feature of the UWB technology is a rigid, monolithic structure that copes well with seasonal ground movements. In addition, the insulation located under the Swedish plate prevents the soil from freezing, as a result of which the risks associated with swelling and sedimentation are reduced. During the operation of the base, you can not worry that it will deform and crack during the cold winter months.

Advantages and disadvantages of UWB

The technology for building an insulated Swedish slab allows you to build a foundation with your own hands and is similar to the process of building more common strip foundations. At the same time, the monolithic support structure has structural and functional differences that give it a lot of advantages:

Since the construction of the UWB does not require digging a deep pit, there is no need to use heavy vehicles and earthmoving equipment. All work can be done with your own hands, which means that you can reduce the cost of building a foundation.
The monolithic slab, equipped according to Swedish technology, has insulation not only under the sole, but also from the sides. The constancy of temperature over the entire area has a positive effect on the service life of the base.
The design of the slab allows the installation of the main engineering communications even at the initial stages of construction. This allows you to reduce the cost of construction and speed up work. In addition, there is no need to equip the technical underground with water supply and sewerage pipes.
A monolithic reinforced concrete base is suitable for construction in any area, regardless of the soil structure. Since the slab is located on the surface of the earth, it is not affected by groundwater, which increases the bearing capacity of the structure. The foundation can be used with equal success as for small wooden houses, and three-storey cottages.
The tightness of the base and the absence of so-called cold bridges prevent the spread of dampness, mold and mildew.
The ideally flat upper plane of the insulated Swedish slab is a ready-made rough base for laying front floor coverings. Thanks to this feature, finishing work time is reduced and their cost is reduced.
Swedish insulated board has good thermal insulation ability. This, as well as the underfloor heating system laid in the reinforced concrete base, allows you to reduce heating costs and make the house more comfortable.

Ideally flat UWB surface is used as a subfloor

Despite all the strengths of the UWB foundation, there are many people who treat the technology with a fair amount of distrust. As arguments against the construction of a warm reinforced concrete base, they cite the following arguments:

high price;
technology does not provide for the construction of basements;
insufficient rigidity of the thermal insulation layer, which can subsequently provoke shrinkage of the building;
the risk of damage to polystyrene foam by rodents;
lack of data on the durability of the insulation used - the technology is still poorly tested by time;
complication of the design of the slab foundation on sloping surfaces;
restriction on the height of buildings.

It should be said that some of these arguments are not without rational grain. As for the statements about large material costs, today we can say with full confidence about their exaggeration. So, during the construction of the UWB, you can do without the use of construction equipment, having done the lion's share of the work with your own hands. In addition, it will be possible to save on the arrangement of the subfloor and the technological underground. Part of the costs will be returned indirectly, by reducing the cost of heating during the operation of the building.

Swedish slab foundation design

The basis of the insulated Swedish foundation is an ordinary monolithic reinforced concrete slab, which has been used in private construction since the middle of the last century. As for outstanding indicators of sustainability and energy efficiency, they are provided by many design features.

The basis of the UWB foundation is an ordinary monolithic reinforced concrete slab

So, the UWB consists of the following elements:

Sand-gravel or gravel cushion, which performs the functions of a drainage system and serves as a kind of damper during seasonal soil fluctuations.
Geotextile fabric that prevents clogging of the drainage layer with small soil particles.
A waterproofing layer capable of protecting a reinforced concrete structure from the harmful effects of moisture.
A layer of thermal insulation, which is laid both under the entire plane of the junction of the slab to the ground, and on the sides of the foundation. "Pie" of insulation and waterproofing layer prevent the spread of heat into the ground, helping to reduce energy costs.
Drainage and water disposal system. Thanks to them, the supporting structure will not be exposed to precipitation. Even if the melt and rainwater on the site drain into the lowlands, and the underground waters are at a depth of 3 m or more, the presence of moisture removal systems can extend the life of the base plate for decades.
Reinforcing frame or belt. Being a rigid spatial structure made of thick metal rods, this element makes the foundation more durable.
As you know, concrete resists compressive loads well, but weakly resists bending and tensile stresses. To eliminate such shortcomings, a reinforcing belt is called upon, which perfectly copes with elastic deformations of any type.
Engineering communications, which include sewerage, plumbing, electrical wiring and cable channels for pulling communication lines.
Floor heating system. Experts recommend laying the water circuit directly at the stage of foundation construction. This allows you to reduce the cost of construction and contributes to uniform heating of the base of the floor.
Bearing concrete slab, the thickness of which is selected depending on the characteristics of the soil and the weight of the building. To increase the strength of the reinforced concrete base, it is made with stiffeners. They are placed under external walls, as well as in places where columns and other material-intensive elements are installed.

The reinforcing frame makes the Swedish plate resistant to any alternating loads

Of course, such a simple design cannot bear the load in the form apartment buildings high-rise, but in the field of private construction, it will provide proper reliability and durability. Only by installing an insulated Swedish plate, heating costs will be reduced by 15-20%, not to mention the possibility of construction in difficult conditions without the involvement of expensive machinery and equipment.

The construction technology of the insulated Swedish plate

The UWB construction technology described below can be used on soils of any type, except for peaty, soil-vegetable and silty. If they are found, it will be necessary to remove a layer of soil and replace it with compacted sand. Hthe bearing capacity of the base must be at least 1 kg / cm 2. This will make it possible to build a building up to 3 floors high with load-bearing structures made of any materials - bricks, gas blocks, frame panels, glued beams, etc.

Insulated Swedish slab can support the weight of a building up to three floors

Method for calculating the thickness of a reinforced concrete base

Determining the thickness of the foundation slab is the most important design step. An inaccurate calculation or selection of UWB parameters "like a friend's" can end in failure. A house foundation that is too weak may crack after the first winter, or be overly massive, causing waste of money.

The original drawing of the famous Swedish company Dorocell defines the main parameters of the UWB

Note that it is impossible today to make a full-fledged calculation of the insulated Swedish plate, based on the norms of SNiP and GOST. This is due to the fact that the Russian design community does not have any recognized regulatory documentation or fundamental calculations. But what can I say - in the above-mentioned normative acts there is no such thing as UWB.

Nevertheless, one should not think that all Scandinavian-type slab foundations are built “by eye”. The calculation method, although not as detailed as we would like, exists. The fact is that at the beginning of the era of plate building, the documentation of the Swedish company Dorocell got into the Russian segment of the Internet, thanks to which, albeit in a somewhat truncated form, it became possible to determine the design parameters of the UWB.

Of course, the approach to the design of monolithic foundation slabs given below is simplified and cannot be compared with the calculation made by engineers of foreign design and construction organizations. However, it can be used with full confidence for private construction.

Table: optimal specific pressure that the foundation slab should exert on the ground

Before proceeding with the calculations, the prevailing type of soil is determined and its bearing capacity is determined from the table above. If there is a need for construction on the soils in bold, it is recommended to consult with professionals. As can be seen from the table, plastic sandy loams and hard clays have the highest specific pressures, and therefore require the installation of a massive base. The main calculation is carried out according to the following scheme:

According to specific gravity tables various materials calculate the weight of the building without taking into account the foundation. The resulting value should be added to other loads. At the same time, the operating pressure that will be exerted by the equipment and furniture installed in the house, as well as the climatic load in the form of precipitation, is taken into account.
If the angle of the roof slope is more than 60 degrees, then for any region of Russia the climatic load can be neglected.
Focusing on the size and configuration of the building, calculate the area of the slab foundation.
By dividing the mass of the building by the area of the slab, the value of the specific load on the soil is obtained without taking into account the pressure exerted by the reinforced concrete structure. This figure is compared with the load value from the first table and the deviation from the optimal value is determined. The difference between the calculated and required load must be multiplied by the area of \u200b\u200bthe base - this is how the desired mass of the slab is obtained.
The volume of the base is determined by dividing the weight of the monolithic structure by the density of reinforced concrete 2500–2700 kg / m 3. Divide the volume by the area of the slab - this is how its thickness is obtained.

The calculated value is rounded to the nearest 5 cm, after which the weight of the foundation is recalculated. Adding it to the weight of the building, the specific pressure on the ground is again determined. The deviation from the optimal value should not exceed 25%.

Table: operating load and specific gravity of walls, ceilings and roofs

Load-bearing walls, piers and columns	Specific gravity, kg / m 2
In half a brick (thickness 12 cm)	from 200 to 250
From gas and foam concrete (thickness up to 30 cm)	180
From logs (diameter up to 24 cm)	135
From glued laminated timber (section 15 cm)	120
Frame with internal thermal insulation (thickness 15 cm)	50
Floor elements and operational load
From monolithic reinforced concrete	500
From cellular concrete	350
210
Attic ceiling with wooden beams and thermal insulation with a density of not more than 200 kg / m 3	150
Interfloor and basement ceilings with wooden beams and thermal insulation with a density of not more than 200 kg / m 3	100
105
190
100
50
Natural ceramic tiles	80
Slate	50
Ruberoid in two layers	40
Sheet metal, corrugated board, metal tile	30

If, as a result of the calculation, the thickness of the foundation goes beyond 15–35 cm, then its installation is considered inappropriate. If the slab is less than 15 cm, then this indicates an excessive mass of the building for this type of soil. Under these conditions, independent construction is associated with risks, so careful geological exploration and professional calculations will be required. With a slab thickness of more than 35 cm, you can abandon the UWB foundation and install the house on strip base or columnar supports.

When building a Swedish plate with your own hands, it is possible to choose the most convenient construction scheme on your own

What you need to build a UWB with your own hands

Before starting construction, you should prepare the following materials:

high-strength extruded polystyrene foam for foundation foundations - not less than 0.3 m 3 per 1 m 2 of the slab area;
steel reinforcement Ø10 mm (consumption up to 15 p. m per 1 m 2 UWB) and Ø12 mm for grillages (it will take at least 4.5 p. m. per 1 p. m of the distributing structure);
knitting wire;
plastic supports for mounting the armored belt;
polyethylene film with a thickness of at least 150 microns - up to 1.2 m 2 for each square meter of foundation;
geotextile fabric - up to 1.4 m 2 per 1 m 2 of the slab;
edged board or panels for the construction of formwork - from 1 to 1.5 m 3;
sand;
crushed stone of the middle fraction;
concrete - from 0.15 to 0.25 m 3 per 1 m 2 of UWB, depending on the thickness of the latter.

In addition, you will need polymer pipes, fittings and other parts for arranging an underfloor heating system, as well as everything you need for installing utilities.

For UWB, special polystyrene blocks of high hardness are used. Their configuration allows for gap-free laying.

List of tools that will be needed in the work:

bayonet and shovel shovels;
construction stretcher or wheelbarrow;
manual rammer or vibrating plate;
level or water level;
Bulgarian;
electric screwdriver;
deep vibrator;
plastering rule, grater and trowel;
roulette;
hacksaw;
trowel;
hammer.

The use of a vibrating plate makes it easier to work when compacting a sand and gravel cushion

If the concrete will be prepared independently, then, among other things, you will need a concrete mixer and materials for preparing the working solution.

The construction site is cleared of debris and weeds.
The foundation is marked with a level or level, fixing the outer contour with pegs and a cord.
In the marked area, excavation is carried out to a depth of 0.3–0.4 m.
When building a shallow UWB foundation, you can do without earthmoving equipment, but when such an opportunity arises, why not take advantage of it
The bottom of the pit is covered with a 15-centimeter layer of sand, which is abundantly spilled with water and carefully compacted. To do this, it is better to use a vibrating plate, but in the absence of the latter, you can get by with a manual rammer.
Vibrating plate is the best tool for compacting sand and gravel backfill.
Geotextiles are laid on the prepared sand cushion. The edges of the canvases should protrude beyond the plate by 20-30 cm.
A gravel or crushed stone cushion (fraction no more than Ø20–40 mm) 10–15 cm thick is arranged over the filter material. Its sides are wrapped with geotextiles protruding beyond the foundation contour.
A crushed stone pillow must be separated from the sand with a layer of geotextile
Engineering communications are laid in the crushed stone layer - sewer and water pipes, electrical cables, etc. The height of their branches is calculated taking into account the thickness of the foundation "pie". To install pipes in the design position, they are temporarily fixed with pieces of reinforcement and plastic clamps.
Engineering communications are laid inside the crushed stone dump
On the sides of the foundation, side formwork elements are installed from high-density insulation 5–10 cm thick. For thermal insulation, fiberboard plates or extruded polystyrene foam are used in the form of special L-blocks and corner elements, but you can also take ordinary, flat panels. The insulation material should have maximum hardness and low moisture absorption, so it is best to use a special insulation for concrete bases (for example, Penoplex Foundation, Penoboard, etc.). from a bar with a section of at least 50x50 mm.
For the installation of the enclosing structure, extruded polystyrene foam is used.
A layer of waterproofing is laid on top of the compacted crushed stone cushion. It can be like modern roll materials, and the usual ruberoid. The main thing is to ensure the tightness of the moisture-proof layer, so the individual canvases are overlapped, with a 15-centimeter overlap. Joints are sealed with a gas or gasoline burner. It is important that the edges of the sheets protrude beyond the perimeter by at least the thickness of the concrete slab - subsequently, they will be used to ensure waterproofing of the ends.
Equip the first layer of thermal insulation. To do this, polystyrene foam plates with a thickness of 10 cm are continuously placed on the surface. In places where sewer and water pipes pass through the foundation, cutouts are made in the sealant.
The lower layer of thermal insulation is laid solid, with cutouts for communications
The second layer of insulation is laid out from the same polystyrene foam boards, but they are not placed continuously, but in accordance with the design documentation. In the areas of operational load, namely where the finishing floor will be equipped, the total thickness of the thermal insulation should be 200 mm. As for the bases of load-bearing walls and columns, they are left only half filled for subsequent reinforcement and pouring of concrete grillages (stiffening ribs).
The top layer of thermal insulation is laid in accordance with the design documentation
When laying polystyrene foam insulation, it is important to exclude gaps, since when pouring concrete, so-called cold bridges will form in these places. To temporarily fix the plates of the second layer, you can use polyurethane glue or self-tapping screws with a length of at least 120 mm.
Perform reinforcement of poured grillages. To do this, away from the construction site, separate metal frames are made from 4 rebars Ø12 mm, which are oriented in the longitudinal direction. Spatial fixation of the main reinforcement is carried out using a rod Ø10 mm, which is mounted in increments of up to 300 mm and fastened with a knitting wire. After making a sufficient number of frames, they are installed in a mold and tied together.
Prefabricated three-dimensional frames are used to reinforce the grillages.
Reinforce operational load zones. For this, reinforcement Ø10 mm is used, which is tied into a mesh with cells of 150x150 mm. In most cases, one row of rods will suffice. In order to provide a protective layer of concrete with a thickness of at least 30 mm, the mesh and reinforcing frames of the grillages are installed on factory plastic FS-30 clamps or home-made supports made of steel bar with a diameter of 6–8 mm.
To reinforce areas with operational load, a single-layer mesh of reinforcing bars is assembled
If there is a need for longitudinal joining of the rods, then it is necessary to ensure an overlap of rods with a length of at least 20d. So, for fittings Ø12 mm, the connecting part should be 240 mm.
Lay plastic pipes of the floor heating system, which are attached to the reinforcing mesh with plastic clamps.
Floor heating circuits are conveniently attached directly to the reinforcing frame
At the intersections of the underfloor heating contour with grillages, over which the supporting structures and wall partitions will be mounted, the pipes are protected with sleeves made of HDPE pipes 40–50 cm long. Collectors are installed and, using corrugated pipes, provide protection for floor heating pipes in places of their rise. Underfloor heating switchgears can be attached to two 1.5 meter Ø12 mm rebars, which are driven into the base of the foundation at an angle of 90 degrees.
To fix the collector board, metal rods driven into the ground are used.
The floor heating system is filled with coolant and pressure tested to test its tightness.
Prepare the form for concreting. To do this, they control the correctness of the previous steps, remove debris and make sure the integrity of the formwork. The outlets of the water and sewer pipes are protected from the ingress of the solution, for which special plugs or any suitable materials are used - rags, pieces of polyethylene, etc.
The form is filled with concrete, distributing it over the surface with shovels. It is necessary to ensure that the solution flows under the reinforcement, into corners and other hard-to-reach areas, for which it is convenient to use a deep vibrator. The filled form is compacted with a vibrating screed or a plate and the surface is leveled with a rule and a trowel. After that, the foundation is covered with a plastic film.
Pouring concrete into the formwork begins from the corners, leveling it to the center of the foundation

Concrete will acquire the required strength only if the correct temperature and humidity conditions are provided. Too fast drying of the solution should not be allowed - in this case, dehydration reactions (setting) slow down and temperature and shrinkage deformations occur.

If the foundation is poured in the hot, summer months, then its surface should be watered with water already 2-3 hours after pouring, and at another time - no later than 10-12 hours. After moisturizing, the form must be covered, repeating the procedure for the entire first week, several times a day. So, at a temperature of 15 ° C in the first 2-3 days, it is necessary to water the concrete every 3 hours, and the next days - at least 3 times a day, with the most abundant moisture at night.

A day after the start of setting, the surface of the foundation can be covered with a layer of wet sand or sawdust. Due to the fact that these materials retain moisture well, the interval between waterings can be increased by 1.5–2 times.

If the construction is carried out in accordance with the technology, then the foundation will have not only high strength, but also excellent performance properties.

Possible problems and ways to prevent them

The stability and durability of the building depends on the correct calculation of the thickness of the foundation. If the slab is excessively massive, then the house will shrink. An insufficiently powerful base can contribute to the distortion of the walls and the appearance of cracks. On difficult soils, it is better to entrust the design to specialists.
During the off-season, construction on sites with high groundwater levels can be difficult. In this case, it is required to carry out a set of measures to drain the base under the insulated Swedish stove. To do this, a trench is dug around the foundation, in which drainage is arranged. In some cases, laying drainage pipes may be necessary under the sole of the slab.
The amount of concrete required to pour the UWB is measured in cubic meters. The spreading mortar exerts a strong pressure on the formwork, which can lead to its bending and damage. To prevent this from happening, a wooden support is driven into the ground every 0.5 m along the outer perimeter of the enclosing structure and spacer bars are installed.
They try to fill the slab in one go, since a violation of the solidity of the structure can cause cracks to appear at the border of individual portions of concrete. However, if it is not possible to pour the form at one time, then the process is divided into several stages, placing individual layers of concrete horizontally.
When arranging the reinforcing frame, make sure that the metal rods are covered with a layer of concrete at least 3 cm thick. Otherwise, moisture can penetrate inside reinforced concrete structure, gradually destroying the foundation. For the same reason, it is not allowed to mount the armored belt on vertical rods driven directly into the ground.

Thanks to my versatile hobbies, I write on various topics, but my favorite ones are engineering, technology and construction. Perhaps because I know a lot of nuances in these areas, not only theoretically, as a result of studying at a technical university and graduate school, but also from the practical side, since I try to do everything with my own hands.

Foundation - insulated Swedish slab (UShP) 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 at home, and, in principle, the construction of the foundation as a whole. The UWB foundation for the post-Soviet period is a relatively young option.

For the first time, information about the foundation of a warmed Swedish slab appeared on construction forums 10 - 15 years ago. There he was very actively discussed. But a number of points that you should definitely know when using such foundations have been omitted. Mostly there were laudatory odes to this foundation.

Pros and cons of UWB

Advantages of UWB, like all slab foundations	Disadvantages of UWB and all slab foundations
The loads are transferred quite evenly, since the slab, more than just a tape, distributes the loads and transfers them evenly to the base in the form of soil under the foundation.	They are subject to the risks of heaving and uneven settlement, as they are located in an unfavorable zone of soils with a low bearing capacity, as well as in the freezing zone, tk. they are not deepened by the bearing base to the depth of freezing.
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 are required. The result is a monolithic layer of concrete, which is very important for the foundation.	There are nuances in the arrangement of communications and the relief of the site
Small amount of work. Unlike monolithic strip foundations, UWB work is much less, both earthwork and reinforcement binding, concrete acceptance, and formwork.

Differences from the usual slab foundation:

The UWB device uses a large amount of insulation. It is used along the perimeter of the foundation and usually not to the freezing depth, but to the depth of the foundation device, this is usually 600 mm, which corresponds to the standard size of an extruded polystyrene foam sheet.

Also, the insulation is used directly under the stove and the blind areas are necessarily 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 of a failed decision than a rational one.

After this type of foundation was promoted at construction forums, it was actively picked up by manufacturers of polystyrene foam insulation and made technological maps, instructions for arranging these types of foundation. As a result, the topic of UWB has gained even more status as a professional solution for laying the foundation of a private house. It is not without reason that these manufacturers became interested in this particular foundation technology - it uses a very large amount of insulation and most of it is used simply irrationally, one could safely do without it.

Marchenko expresses the opinion that this technology is more beneficial not for the owners of the future house, not for builders, it is beneficial for the producers of expanded polystyrene.

Dmitry Marchenko studied this foundation in detail and did not see any other persons interested in this foundation, except for the producers of extruded polystyrene foam.

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

Reality and advertising by UWB

ADVANTAGES SPECIFIED FOR UWB	THE REALITY OF THE UWB FOUNDATION
UWB is a fairly cheap type of foundation, because a much smaller amount of reinforcement, concrete is used, a much smaller amount of excavation and monolithic work.	In comparison, a tape monolithic foundation is usually taken. Indeed, less concrete is used in UWB - the thickness of the slab is only 100 mm and less reinforcement - reinforcement is knitted in just one layer. But long-term practice shows that one layer of reinforcement is not enough here. You need 2 layers of reinforcement and they must be tied with clamps with a certain pitch, make additional “pawns” from the reinforcement. But this is not the case in the proposed UWB technology. That's why main disadvantage this foundation is a weak slab. Also in this foundation a lot of high-quality insulation is used. And any insulation will not work here, it is high-quality and expensive extruded polystyrene foam that is needed. And for example, for a house with a stove measuring 10 x 10 meters, 18 cubes of insulation will be required. And the foundation with so much insulation becomes simply “golden” in value. For the price, it covers even a monolithic strip foundation. Therefore, such an advantage as a low price is fundamentally not true. Also, not the cheapest pleasure is the device of a sand cushion. First you need to choose your native soil, then bring in the sand. The sand must be moistened in layers and compacted, all this must be MANDATORY observed. These are additional costs.
UWB is suitable for building houses on any soil, both heaving and non-heaving, subsidence and non-subsidence, etc.
This foundation evenly distributes the load.
Suitable for all types of houses - wooden and brick and lightweight concrete, etc.

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

For example, they don’t do it in layers, or they don’t spill it enough, or vice versa, they fill it with sand and then it cannot be compacted properly. And even if all this is done with high quality, all the same, over the entire area of the sand cushion, places of uneven tamping are possible. 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 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 the reinforcement in one layer will be extremely insufficient for the foundation to retain its geometry and not crack, which will result in a crack in the supporting structures of the house. Thus, the sand cushion affects the stability of the whole house.

Also a disadvantage is the possible deformation of the EPS itself. Despite the fact that the manufacturer claims the high technical and operational characteristics of its products, that the material has very high compression rates, 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 that its durability is questionable. Despite the fact that manufacturers claim ideal qualities, there are very few stories of using XPS in this way, there is no evidence of its caking within 10-15-20 years, and this calls into question the integrity of the whole house. There is no certainty that a person would be willing to risk their investment in a house in order to experiment on themselves how conscientious an EC manufacturer was.

The disadvantages of this foundation, as well as other slab foundations, is a low base. Usually it is 10 cm already from the blind area mark and the wall structures of the house are in very close proximity to the ground, which means they will be in a zone of high humidity, which is a very vulnerable moment for our climate. A 10 cm high plinth is not enough for our climate, in our climatic conditions the plinth 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 a flat area and the absence of any slopes from either side towards the house, because. any rain or melt water will wet the side parts of the foundation base and these places will unevenly heave, will undermine the blind area, it may even lead to the raising of some part of the foundation, and if the foundation is uneven, deformations may occur on the foundation or on wall structures.

Most technological maps or instructions for arranging this foundation imply a drainage system. It must necessarily be arranged in a warm zone of the earth, otherwise the drainage in the first winter will most likely simply be torn apart by heaving. It will be filled with water even in winter, when the temperature is below zero, it will simply freeze and tear it apart. 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 constructing 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 arranged in the form of geotextiles, but practice shows that there are junctions and some shortcomings of the builders, as a result, the drainage systems are flooded. There is a way out that partially solves the situation, inspection hatches are being built through which drainage systems can be flushed under the pressure of water, but in most cases hidden drainage systems are not the best solution, especially if this is not done by drainage specialists, but by ordinary builders. foundation device. In such cases, very often important points are missed, because if there is no practice, it cannot be replaced with information from the Internet. Moreover, it is easy to lay drainage pipes not enough. It is necessary to make a branch with a slope, it is necessary to make a receiving well, install a drainage pump. This will increase the cost of construction even more.

On the site you will have to allocate space for a drainage well, regularly maintain and monitor it, clean the drainage system, which with a high probability will 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 the settlement of the foundation. This is another minus to questions about the price of this foundation. On this we can already say in principle that this type of foundation is not profitable.

But its shortcomings do not end there.
Private houses are built, as a rule, outside the city, where rodents, ants, etc. are found in large numbers. And the insulation under the foundation for them is an ideal place for arranging holes. The insulation will not be complete, and the pressure from the house will remain the same. From here, deformations, drawdowns of the insulation are possible, and with it drawdowns of the foundation. And within 10-5 years, the picture with the geometry of the foundation can dramatically worsen.
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 \u200b\u200bthe house, insulate the foundation to prevent freezing of the slab, to prevent frost from getting under the foundation, even monolithic, therefore, when installing insulation from EP, the right solution is always to equip a protective mesh . But if you protect the entire volume of insulation with a metal mesh, then it is very expensive, and it’s not a fact that ants will not be able to get there.

As for underfloor heating during the construction of this foundation: The layout of pipes for underfloor heating can already be carried out at the stage of its construction. Underfloor heating pipes are fastened 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 there are underfloor heating pipes, which means you will not need to make the installation of underfloor heating according to the insulation with a classic system, when insulation is arranged on the monolithic slab of the house, underfloor heating pipes are laid, a screed is made, and as a result you also get a warm floor, but you pay extra money for these works.

The floor screed, which is arranged along the pipes of the warm floor, has a relatively low density, and, accordingly, the heat capacity, in comparison with a monolithic slab. This allows the underfloor heating pipes to warm up the screed layer relatively quickly and release heat into the room. If you look at the underfloor heating system in UWB, then unlike the classic screed. we get: the plate itself has a high density and high heat capacity, which means that in order to heat this plate, 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 finishing coating is 5-6 cm, then in the case of UWB 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 kind of thermal effect from the floor heating pipes begin. This system is very slow to heat up and cool down. therefore, if we compare the installation of underfloor heating, then the classical system is more advantageous, because. it allows, at lower costs in heat energy, to transfer this energy to the room faster.

Because Since this system is directly connected to water, it may have leakage problems. Construction workers may accidentally crush or damage the pipe, which may result in the need for repair. In the case of the classical system, the screed is broken, the place of breakdown is located and eliminated. Here, it is not difficult to find a breakdown site, because. it will be a wet spot on the floor. and in the case of a monolithic slab, finding the place of 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 broken. And in the case of a screed, the search for and elimination of a hole will not affect the integrity of the supporting structures.

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

Do-it-yourself UWB foundation: calculation, technology. UWB is a foundation that is heat efficient and modern. By the way, this is not only a foundation, and not just a slab, it is the real foundation of your home. It includes a ready-made comfort heating system with underfloor heating throughout the entire area of the house, piping for water supply, electrical cables and sewerage, high quality floor insulation, and the smooth surface of the UWB is suitable even for laying a fine floor covering.

Swedish stoves are suitable for frame houses, as well as houses made of timber, logs, SIP houses and others, i.e. You can build on any type of .

Before pouring concrete, a lot of other things follow, and we will start with the preparation of the pillow - this is the base on which the formwork will be placed, on which the slab will be located. It is necessary to prepare a sandy flat area and tamp it well with the help of special equipment, a vibrating plate. It is interesting that the "stuffing" of the pillow will depend on the type of soil, starting with the usual removal of the fertile layer, filling it with sand and tamping, ending with the full placement of the soil under the slab at great depths and tamping with the help of heavy vibratory rolling. The preparation of the pillow is quite an important milestone in construction, and then, at the very end, the quality of the seal should be checked with a penetrometer.

Setting up formwork made of XPS/PSB

Due to the fact that the warm floor is poured into concrete, a monolithic concrete slab will serve as an excellent heat accumulator. It will not warm up immediately, gradually, but when it gains heat, it will give it away for a very long time. Even if an emergency occurs and your electricity or gas is turned off, it will not be felt immediately, only after a day or more. Yes, the temperature in the house will drop slowly.

Conducting communications - water, electricity and sewerage

Now let's talk about how to conduct, namely sewerage, electricity and water. In addition to the underfloor heating, communications are also laid inside the slabs, namely cables (electric, which can even be led out into the walls), pipes for hot and cold water, sewer pipes, water drains for the future shower room, as well as other cables and air ducts. This is the standard set.

The UWB foundation slab is not made for an abstract house with only estimated dimensions. At a minimum, you will need a draft design, and then it will be possible to immediately bring heating to the rooms, bring pipes to the kitchen and future bathrooms, install floor heating collectors and supply water in the technical room.

Concrete monolithic slab as subfloor

And the final work on the UWB is the pouring of concrete and its grouting or grinding. When all the underfloor heating and communications are ready, the cables and leads are checked, the integrity of the pipes is tested due to pressure, you can call the mixer and start pouring the concrete mix High Quality. You can not use homemade concrete, only a mixture from the best concrete plant, and the latter must have all the required documents, certificates and samples.

After a certain time after the pouring has been carried out, when the concrete has gained a little strength, you can start grinding the surface using a special trowel, which is commonly called a “helicopter”. Both during pouring and grouting, the evenness of the slab should be constantly monitored, and the laser level will help you with this. As a result, you will get a smooth concrete base with minimal differences. After that, you can immediately start laying or tiling, and you will not need to fill in an additional screed - everything will be ready anyway.

Results

So, when ordering a UWB foundation upon completion of work, you will receive:

When comparing UWB with screw piles or with a standard concrete slab, we find that the comparison is not in favor of all other types. Naturally, piles will be cheaper, and on them you can also build enough good house, but imagine how much work will be done for later? Who will carry them out and how much will it cost?

When evaluating and comparing the cost of different types of foundation, all of the above factors should be taken into account. UWB is a ready-made zero cycle, a kind of turnkey foundation. You can also install a box at home on the UWB, and the rest will already be done inside - communications, heating and insulation. By comparison, in a house on the same screw piles, you will need to make a lower floor, insulate it, carry out communications, make wiring around the house, pour a screed, install a heating system, and come up with something with a high base finish. As you can see, the first option has many more advantages, but what type of foundation to choose is up to you!

In low-rise construction, you can do without pouring a monolithic concrete foundation and make a reliable, warm foundation for the future building. This opportunity is provided by foundations made using technology. UWB.

The abbreviation stands for insulated Swedish stove, which is effectively used in European countries. In Russia, the technology became known since 2009, but is not currently widely used - developers are just starting to master it.

The lack of interest is caused by the lack of complete and reliable information about this type of foundation. At first glance, the technology seems complex and expensive. In fact, the cost of work is lower than pouring a conventional monolithic concrete slab.

The structure of the insulated Swedish plate

The data in the article is purely informative and is not an instruction for arranging a UWB foundation: it requires precise engineering calculations that are tied to a specific building site.

There are several arrangement options, however, the differences are personal in nature and do not affect the overall installation technology. In fact, the Swedish foundation resembles a multi-layered pie, consisting of the following elements:

ground base with a pre-prepared drainage system;

geotextile substrates;

sand and gravel pads with supply areas sewer pipes and engineering communications;

insulating layer;

waterproofing;

second layer of insulation;

strapping from fittings and underfloor heating systems;

concrete slab (medium thickness 100 mm);

floor finishing.

At first glance, the design seems cumbersome and complex, but this is an illusion. All work can be done on your own without the involvement of heavy construction equipment.

Provided that the work is carried out correctly at all stages, a solid foundation is obtained, with stiffeners and a standard heating system. This design completely prevents possible heat loss, while it has a high bearing capacity.

Advantages and disadvantages

Pipes do not need additional insulation.

Reliable protection against groundwater.

The possibility of building a foundation on all types of soil, except rocky.

Reduction of heating costs due to the "warm floor" system.

You can do without the use of bulky construction equipment.

Accelerating the process - a full cycle from preparing the base to finishing takes no more than two weeks.

Uniform load distribution, resistance to deformation.

Inability to eliminate errors made during the construction process.

The need for backup communications.

There is no possibility to make a basement and basement.

Some of the shortcomings can be eliminated if the work is entrusted to qualified designers and workers. However, the involvement of specialists makes the financial benefit less attractive.

UWB or monolithic foundation?

At first glance, the economic benefits of arranging the UWB are imperceptible - a large amount of building materials are required, which cost a certain amount of money. The estimate includes the purchase of:

insulation;

fittings;

floor insulation systems;

other materials.

When pouring a monolithic foundation, such expenses are not required: the foundation is prepared, reinforcement is purchased, piping is made and concrete is poured. However, the financial benefits of pouring a monolith are understandable only to non-professionals.

Such a foundation can be compared to a bank loan: if there are not enough funds, fill the site, and then gradually build further. The process turns out to be extended in time, which implies a rise in the price of building materials. In addition, the monolithic foundation needs to be insulated and waterproofed, utilities will also be connected to the building.

UWB is suitable for people who understand the benefits of such a design and build a house that will be warm and cozy, regardless of the vagaries of the weather. If you make calculations for energy savings for 10 years forward, the attractiveness of the insulated foundation will increase. Against this background, a monolithic foundation looks like an ordinary slab, which requires additional investment.

Step-by-step technology for arranging UWB

The workflow begins with the involvement of technical experts who are able to calculate the bearing capacity of the soil, the likelihood of seam movement and the drainage system. After that, the arrangement of the foundation is carried out in a certain sequence.

The Swedish foundation is never laid on a fertile soil layer: this is guaranteed to lead to a shift in the structure during the construction of the building. Therefore, such a layer of soil is completely removed from the construction site.

The pit is made shallow: usually 2-3 shovel bayonets, however, its external dimensions should go one meter beyond the boundaries of the walls of the future building. The bottom of the pit is lined with geotextiles with the substrate running on the side walls.

Storm sewerage and groundwater drainage are necessary in order to ensure the dryness of the foundation. For these purposes, geotextiles are covered with a layer of rubble, an underground reservoir is made with pipes connected to it. To lay the drainage system along the perimeter of the pit, trenches are formed with a slope towards the main well.

Engineering communications

The next step is the distribution of pipes for water supply and sewerage. Communications are necessarily deepened below the level of soil freezing in winter.

In addition, it is necessary to plan in advance the location of the risers in the house, bring the pipes outside to connect to centralized or autonomous water supply systems.

Given the shortcomings of UWB, it makes sense to immediately duplicate the communication system in order to use the reserves in case of a malfunction. At this stage, a sand cushion is added, which is necessarily compacted by a rammer.

The first layer - closes the perimeter of the pit completely.

Second - recedes at 40-45 cm inside.

This is necessary in order to install along the edges L-shaped modules from expanded polystyrene for an external bypass.

At this stage, the distribution of the "warm floor" system is carried out with the installation of collectors and temporary pressure testing of pipes. Next, a two-layer reinforcing belt is made from reinforcement with a diameter 12-16 mm. Recommended grid pitch 15*15 cm.

Formwork manufacturing

For this, they can be used L-shaped modules expanded polystyrene, reinforced on the outside with boards and spacers to prevent their extrusion under the action of the concrete mass. Can also be applied classic version: internal frame, knocked together from thick plywood boards. The formwork height is calculated based on the following values: insulation thickness (20-30cm) and the plate itself (no more than 10 cm).

This stage does not differ from the arrangement of a monolithic foundation. The concrete mixture is fed continuously to prevent the formation of joints and is necessarily compacted with internal vibrators to evenly fill the internal space.

Keep in mind that the contact of the vibrator with pipes of "warm floor" or reinforcing mesh is highly undesirable.

Formwork can be removed after 72 hours after filling. If work is carried out in hot weather, the plate is covered with burlap or plastic wrap, periodically moistened with water. In winter, a heating system is laid before pouring.