Which foundation is better for a house made of foam blocks: pile, strip or monolithic. Reliable foundation for a house made of foam blocks: types, advantages Width of the foundation for a one-story house made of foam blocks

We will tell you about the foundation for a house made of foam blocks, as well as: the construction of a foundation, including a pile foundation, calculations, necessary tools and technology. You will find out prices for foundations in Moscow.

Foam block- a universal building material that has received recent years wide popularity due to its reasonable price, light weight and minimal thermal conductivity.

Foam concrete blocks are larger in size (standard - 20 * 30 * 60 cm) than ordinary bricks, which significantly reduces construction lines - laying walls is much faster.

Rice. 1.1: Comparison of foam block and brick sizes

Due to the low thermal conductivity of the material, foam block buildings retain heat well, and the low weight of foam concrete allows such houses to be built on any type of foundation.

What kind of foundation is needed for a house made of foam blocks?

Recently, one of the clients of the Bogatyr company sent us a letter to our office with the following content:

We decided to answer Victor’s question and on this page all the nuances of choosing and arranging the foundation for a house made of foam blocks will be discussed. We hope that the information provided will be useful to anyone who is asking the same question.

Choosing a foundation for a house made of foam blocks

A house made of foam block, due to the difference in the cost of a cubic meter of material, costs, on average, 2-3 times less than a building of the same size made of brick. The construction time for houses made of foam concrete is also significantly shorter. When choosing a foundation for a foam concrete house, you should try to emphasize these advantages.

Rice. 1.2: One-story house made of foam block with an attic

Foam concrete buildings can be erected on the following types of foundations:

• Tape (shallow and deep);
• Monolithic from a concrete slab.

Rice. 1.9: Screw pile SVSN-108-2000 is one of the most used piles in the construction of foundations for foam block houses

When building a house from foam block on stilts, as a rule, wide-bladed piles with a diameter of 108 mm are used. and 3-5 meters long. The standard pitch of piles in the foundations of foam concrete houses is 2.5 meters. Piles must be placed at the intersection points of walls and at the corners of the house.

Having received all the necessary calculations from specialists, you can begin building the foundation with your own hands with complete confidence.

Required materials and tools

For construction you will need the following materials:

• 24th channel;
• Moisture-proof primer for metal;
• Electrodes (for welding).

It is also necessary to prepare all the necessary tools in advance:

• Manual or mechanical drill;
• Scrap, metal pipes 2.5-3 meters long;
• Magnetic and water level;
• Bulgarian;
• Welding machine;
• Shovels, wheelbarrow;
• Tape measure, pencils.

Technology for constructing a foundation for a house made of foam blocks

The construction of a pile-screw foundation for a foam concrete house is carried out according to the following algorithm:

• First of all, the construction site is prepared. All vegetation must be removed and excavated fertile layer soil (about 20 centimeters), after which the site needs to be leveled to the same level, smoothing out natural differences in height.

Rice. 2.0: Construction site preparation

• Next, the foundation is marked according to the design location of the piles. The first to be marked are the piles on one of the long walls of the building, starting from them - all the others. The places where the piles are screwed in are marked with reinforcing pegs, between which a string is stretched, and the accuracy of straight lines is checked along it;

Fig 2.1: Pile field marking

• Before screwing, the piles are coated with two layers of primer; this is necessary to protect the structure from groundwater. Screwing begins with corner piles: first, a guide hole up to a meter deep is made with a drill, a pile is inserted into the hole, and a crowbar is threaded into the hole, used as a lever for screwing. During the driving process, the vertical position of the pile is controlled by a magnetic level attached to it;

Figure 2.2: Screwing piles

• Upon completion of the installation of all structures, the pile pillars are cut to the same height using a grinder. The identity of the cutting height is determined using a water level.

Figure 2.3: Trimming pile pillars

• Before installing the grillage, the channel must be primed to protect it from corrosion during operation. The channel is secured to the pile posts by welding.

Rice. 2.4: Tying piles with a grillage made of channel

As a result, in 3-4 days of work you will receive a high-quality and reliable pile-screw foundation for a house made of foam concrete, made by yourself.

Fig 2.5: Pile-screw foundation with channel grillage

Prices for foundations of houses of different sizes

If, after reading, you doubt that you will be able to complete the work in accordance with all the technology requirements, it makes sense to turn to the services of contractors.

There are a large number of organizations involved in the construction of pile-screw foundations. In this case, the foundation will cost you more, but you will be sure that it is done correctly.

As an example, we give the estimated cost pile-screw foundations for houses made of foam blocks of different sizes:

The calculation of the cost of the foundation was carried out based on the average market price of the SVSN-108-2000 pile, which is 1850 rubles. and the cost of its installation is 1,750 rubles.

Foam blocks are blocks made of foam concrete, which is classified as porous concrete. This material is popular in private construction due to its light weight, strength and durability. This article will talk about when to use and how to build pile-strip foundation under a house made of foam blocks.

Foam blocks: material features

Foam blocks are lightweight, have good thermal insulation properties and are durable. Foam blocks do not rot or burn. Cement, sand, foaming agent and other fillers are used in their production.

Houses made of foam blocks are not built with more than 3 floors. In general, the buildings turn out to be light, so the foundation can be made not as powerful as, for example, under brick house. Under a foam block house, you can make a columnar foundation, a strip foundation, a pile-strip foundation or a monolithic slab.

When can you use a pile-strip foundation?

This type of foundation is suitable for weak soils. In this case, the tape distributes the loads from the building, and the piles are responsible for supporting the ground. Like any pile foundation, it rests on more reliable layers deep in the soil. It is also used in areas with height differences.

The advantages of this type of foundation include

• speed of construction (about 3 days),
• you can fill it at any time of the year,
• low consumption building materials, hence relatively low cost.

• Only suitable for low-rise construction, small, light buildings,
• it is impossible to build a house with a basement or ground floor on such a foundation,
• difficult to accurately calculate loads,
• not suitable for heaving soil (in this case, you need to make a pile-grillage foundation, where the grillage is suspended).

Thus, it is quite possible to build a house from foam blocks on a strip-pile foundation.

A pile or column foundation is justified for a house made of foam blocks, and when it is necessary to build a safety margin into the foundation, for example, when it is not possible to accurately calculate the loads.

This type differs from a pile-grillage foundation in that the grillage is always located on a short distance from the ground. This is necessary so that the soil has room to expand due to frost heaving. In a pile-strip foundation, the strip can be buried and shallow; it rests on a sand cushion, which is also designed to resist heaving forces.

Usually a shallow (20-40 cm) strip foundation for a house is made from foam blocks with a 20-30 cm sand cushion and bored piles.

Approximate calculation of the foundation

Independent calculation of pile- strip foundation for a house made of foam blocks is quite complicated. It is advisable to entrust this procedure to specialists, however, you can also use approximate calculations.

In order to calculate the foundation, it is necessary to calculate the load from the building, which consists of the weight of all building materials and everything that is in the house. Snow load is also taken into account. Next, it is necessary to take into account the bearing capacity of the soil.

P = 0.7*Rн*S + 0.8*U*Rs*l

where 0.7 is the soil homogeneity coefficient, Rн is the standard soil resistance under the lower end of the pile, t/sq.m. (can be found in the tables, this value depends on the type of soil), S - pile support area, sq.m, 0.8 - working conditions coefficient, U - pile circumference, m, Rs - standard soil resistance of the side surface of the pile, t/ sq.m, (found from the tables), l is the thickness of the soil layer in contact with the side surface of the pile, m. From these data it is calculated required quantity piles depending on the load.

How to make a pile-strip foundation

A pile foundation for a house can be erected on screw, bored, or driven piles. In private construction, the first two types are more often used, since driving concrete piles into the ground requires special equipment. The supports are placed in the corners of the foundation, under the intersection of load-bearing walls, and between these points - at a calculated distance, which depends on the material and size of the house.

First of all, you need to prepare the site: clear it of plants, remove the fertile layer, level it. Next, markings are made. To do this, first transfer the axes of the base to the area, mark the width of the tape, and the places where the wells will be drilled.

The next stage is excavation work. A trench is dug equal in width to the tape if the soil is dense, and wider if the soil is loose. The depth of the trench is equal to the thickness of the cushion plus the depth of the foundation. Next, wells are drilled.

Bored piles are made by drilling holes in the ground and pouring concrete into them. For this purpose, formwork made of asbestos-cement or PVC pipes, or roofing felt or polyethylene rolled into a tube. The formwork not only gives the support its shape, but also makes its surface smooth, which helps resist heaving due to the fact that when shearing, the soil slides along the pile. The fittings are lowered into the pipes. Most often, piles are made with a diameter of 20-25 cm, but not less than 1/3 of the width of the tape, they are placed in increments of 2 m. The depth of the well should be at least 0.5 m below the freezing level of the soil, of which 20 cm is a sand cushion, 30 cm - the pile itself.

Before placing the formwork in the well, sand or gravel pads 20-30 cm thick are poured, compacting them. Next, pipes are inserted into the wells.

The reinforcement of the piles is done so that their frame can be connected to the tape frame. To do this, each support requires 3-4 reinforcement bars and small trimmings as jumpers. They are tied together with knitting wire. The frame is made in such a way that the reinforcement protrudes from the well by 15-20 cm.

If bored supports are made for a foam concrete house, then the entire foundation under the foam block is poured in one step, starting with the piles. Concrete is poured into the pipes, compacting it every 20 cm to avoid voids. It is advisable to use a vibrator for this; in its absence, you can get by with a regular stick. After pouring the first 30 cm of concrete, the pipes are lifted so that the concrete flows out and ensures a good connection between the pile and the ground.

For concreting the tape, formwork is constructed. It is made from boards, plywood, and other materials. The boards are knocked down into panels and connected to each other with self-tapping screws. Additionally, they are reinforced from the outside with supports and connected with wooden planks or clamps.

The reinforcing frame for the tape is made of four longitudinal ribbed rods arranged in two rows. Between them, vertical and horizontal jumpers are made from thinner reinforcement, which can be smooth, tied with knitting wire.

The tape frame is also connected to the pile frame. The reinforcement is installed so that it is at a distance of 5 cm from the edges of the tape. Next, concrete is poured, making sure to compact it with a vibrator or manually with a metal rod. After this, the surface of the concrete is leveled and covered from rain with polyethylene. In hot weather, concrete is periodically watered.

Screw piles are metal pipe with a blade at the bottom. The piles are screwed into the ground, and then cement-sand mortar is poured inside. To build foam block houses and buildings made of other porous concrete, piles with a diameter of 108 mm are used. The distance between piles for a house made of foam blocks should be no more than 2 m.

Insulation and waterproofing

After the concrete has hardened and the formwork has been removed, the foundation is waterproofed and insulated. For waterproofing use bitumen mastic or roll materials. Before applying them, the concrete is coated with a primer and antiseptic. For thermal insulation, it is recommended to use extruded polystyrene foam (EPS). Its sheets are glued to concrete using special glue.

A strip-pile foundation can be used for a house made of foam blocks, since foam concrete is a lightweight material. This type of foundation allows you to increase the load-bearing capacity of piles on weak soil, but on heaving soil, preference is given to the beam pile-grillage option.

Before building any house, dacha, cottage, the area is first studied. What kind of soil, the composition of the earth, is there groundwater underground, are there various communications, cables, etc. running under the site. The composition of the soil is studied at a depth of 2.5 - 3 m. To do this, it is necessary to create a detailed analysis of the soil layers. Since, at ordinary people There is not enough experience in such matters, and you can easily confuse slightly heaving soil with non-heaving or mixed soil, it is advisable to make a request to professional specialists, to certain services. As soon as the soil is ready, you can begin choosing the foundation.

How to make the most reliable foundation with your own hands for a house made of foam blocks, reliably, quickly and inexpensively? First, you need to make a design for your future home. To do this, you need to calculate in advance the weight of the building, determine the type of soil, decide how many floors there will be in the house, and whether there will be a basement.

Required tools:

1. Shovel.
2. Concrete mixer.
3. Roulette.
4. Hammer.
5. Buckets
6. Level - ruler.
7. Drill.
8. Screwdriver.
9. Hammer - pickaxe.
10. Screwdriver.
11. Cord, rope, metal wire.
12. Screws.
13. Chisel.

All types of foundations for houses made of foam blocks

Columnar foundation, suitable for heaving and clayey soils. Typically, one-story buildings are installed on such a foundation. Formation of the foundation in the ground, pillars are dug to a certain depth. For structural strength, reinforcement is laid in the form of a frame. Then the whole thing is filled with concrete mixture.

A pile, screw foundation is erected if the house is planned to be built on a hill or its slope. This foundation is suitable for soft, loose, unstable soils. Each pile must have a recess of 4 to 6 meters as a minimum.

To do this, metal piles are screwed into the soil. A concrete monolithic beam - tape - is necessarily installed on top, for greater reliability. Reinforcement is laid on top of it. And only then the foundation is poured. Pile foundations are also made from hanging piles and rack piles. The process of forming a foundation is the same as for a screw pile.

A monolithic foundation, also popularly called “slab”, is suitable for all types of soil. Since the concrete slab can move with the soil. This type of foundation is not recommended for clay soils.

Formation of the foundation

In order to make a monolithic foundation yourself, you must first dig a foundation pit at least 60 cm deep. Then a “cushion” is poured into it, and waterproofing is laid on top. Only after this the reinforcement is laid in several layers, after which the entire structure is filled with concrete.

Strip foundation, suitable for heaving and clayey soils. It is formed from a continuous ribbon of reinforced concrete along the perimeter of the load-bearing walls of the house. Main principle Such a foundation is that the foundation of the house is not only well stable and reliable, but also light. There are two types of strip foundations: recessed and slightly damaged.

A buried foundation is made as follows: the foundation is laid to a sufficient depth so that the soil does not freeze. It should be remembered that such a foundation should be wider than the walls of the house themselves, by about 100 mm, on all sides. The base of the building must have a minimum of 40 centimeters. After building the base, the reinforcement is laid in two rows, two layers each. However, this type of foundation has its drawbacks.

Firstly, the entire process of forming the foundation takes too much time and effort. Secondly, you must immediately have a certain amount of money so that there is enough for all the building materials that should be purchased in advance. Thirdly, you cannot build such a foundation yourself; you need assistants or a construction team, and their work must also be paid.

Typically, such a foundation is laid during the construction of multi-story buildings, or 3-story mansions with a basement. If, according to the project, the house has a basement, then such a foundation is better than other types.

A slightly damaged version of the foundation, much simpler than the previous one. And it differs from it in that it is suitable for one-story buildings and is laid at shallow soil depths. This type of foundation is low-cost, and even a beginner in the construction business can lay it. The most important thing here is to maintain all the necessary proportions.

So, to begin with, you can use an ordinary shovel; you need to dig a trench yourself, 60 cm deep. Then pour a “cushion” consisting of sand with crushed stone (gravel) into it. You should fill it in even layers of 15 cm each, preferably several times. Now we make the formwork and fill it all with concrete.

Now we make a frame from reinforcement in the upper part of the base and secure it securely. The width of the base should be 10 cm wider than all the walls in the house. A shallow foundation is ideal for non-heaving, hard layers of earth.

Design of structures and loads

Depending on the design of the house, the foundation must support the weight of the entire structure. To do this, both the project itself and the area on which it is planned to be built are thoroughly studied.

For example, if there are ground groundwater, a columnar or pile foundation should be installed, based on reinforced concrete monolithic slabs.

The strip type of foundation is not suitable here. And remember, no matter what foundation you choose for your future home, it must be strong and reliable.

For a columnar foundation, the pillars should be located 2 meters apart from each other. They should be located at all corners of the house, and all places in the house that will subsequently have maximum load, as well as under all load-bearing walls in the house. The more pillars are installed, the more securely your house will stand.

Foundation waterproofing

To waterproof the foundation, you should only have good, high-quality material. It must be laid on the base of the foundation surface. Waterproofing can be both vertical and horizontal. The dryness in the basement and in the house depends on how correctly and efficiently the waterproofing of the foundation is done.

For waterproofing you will need: sand, clay, polymer compounds, roofing felt, geotextiles, any fine drainage.

If a basement is planned for the house, it is advisable to immediately carry out thermal insulation work along with waterproofing.

Properties of a foam block house

1. It is being built very quickly.
2. Minimum financial costs.
3. Good sound insulation.
4. Comfortable stay.
5. Environmentally friendly material.

Approximate dimensions for building a DIY foundation for a house made of foam blocks, as well as the necessary tools.

• Foam blocks - 600 x 300 x 200 mm.
• Foundation bases 6 t. X 6 t. Mm.
• Foundation height - 700 mm.
• The underground foundation is 400 mm.
• Sand layer - 200 mm.
• The crushed stone layer is 200 mm.
• Concrete M 400; Concrete M 200.

What foundation to choose when building a house from foam blocks with your own hands? This question is faced by everyone who has decided to choose a warm and light material for making walls. Foam concrete has many advantages, but has its own characteristics that will need to be taken into account when constructing the base.

The foundation can be called the main and most expensive part of the building. The strength and service life of the entire house will depend on how well it is selected and manufactured. Foam blocks as a wall material have a significant impact on the choice of supporting structures:

• A wall made of piece materials is more sensitive to base deformations. The foundation must connect the individual blocks into one strong structure, so it is subject to high demands. With uneven precipitation in the underground part, a house made of foam blocks will become covered with cracks. This is especially true when building on clay and clayey soils, since they are prone to heaving in winter.
• Foam blocks have less mass than brick or concrete. Unlike the previous property, this indicator becomes an advantage. The smaller the mass of the walls of the building, the less labor and financial costs it will require correct device foundation.
• Good thermal insulation characteristics. In terms of its ability to retain heat in rooms, foam concrete is inferior to wood, but significantly outperforms concrete (10 times) or brick (2-3 times). The lower the thermal conductivity of the walls, the thinner they can be made. In this case, again, the load on the supporting part is reduced.

In general, it turns out that when building a house from foam blocks with your own hands, less powerful foundations are required than for brick or concrete. But it is important to prevent the slightest uneven precipitation. Uniform subsidence of the house is also not desirable, but it is not so dangerous.

What to consider when choosing a foundation

Four types of construction can be used: strip, slab, piles or pillars. When designing the support part, several points must be taken into account:

• bearing capacity of foundations;
• mass of house structures;
• number of storeys of the building;
• properties of soils on the site;
• how close to the surface of the earth is the water;
• climatic features of the area.

Advice! It is also worth comparing the cost of use different options and provide a business case.

Climate and water

Uneven deformations most often occur due to frost heaving. This phenomenon is the bulging of part of the supports located closer to the outer walls of the house. For frost heaving to occur, two factors are required simultaneously:

• moisture;
• temperature below zero.

Consequences of frost heaving.

When choosing the type of foundation, you will need to take into account the level of groundwater and the depth of soil freezing. Clay soils (clay, loam, sandy loam) are most prone to moisture accumulation. They have low water permeability, so they do not allow water to seep in and escape.

It is important to make a foundation for a house made of foam blocks with your own hands, taking into account the depth of freezing. For heaving soils, the sole should be below this mark. If the conditions are not met, additional measures are taken (insulation and reliable waterproofing). Soil freezing is determined according to the SP “Foundations of Buildings and Structures” or according to the SNiP map “Building Climatology”.

Map of soil freezing depth in the European part of Russia. Can be used for reference. Clickable.

Strength properties of soils

Depending on the composition, the following groups can be distinguished:

• rocky and coarse-grained (have the highest strength);
• medium or fine sand (also good foundation, heaving occurs less frequently, strength is high);
• sandy loam (prone to heaving);
• loams and clays;
• bulk soils, dusty or fine sand (they have very low strength, foundations cannot be rested on them).

Detailed information about soil varieties is presented in GOST “Soils. Classification". The lower the strength of the foundation, the more powerful the supporting part of the building will be. Some design options exclude the use of certain types of foundations:

• piles are not driven into rocky or coarse soils;
• For sandy loams, loams and clays it is better not to use columnar supports.

Bulk soils and sand from the last group must be replaced with coarse or medium sand before building a foundation for a house made of foam blocks.

Location of groundwater level

The exact elevation is determined by engineering-geological surveys. You can do the work yourself. To do this, holes are dug out or drilling is performed. The same steps are needed to determine the composition of the soil on the site.

Groundwater can significantly adjust the choice of foundation.

It is required that the water be located at a distance of at least 50 cm from the base of the foundation. This rule is not relevant only for piles. They can be installed at any water level.

Important! When using bored piles or other concrete, it will be necessary to perform temporary water reduction before their production. For screw piles such an event is not required.

House weight

This indicator includes the load from walls, ceilings, roofs, partitions, and the dead weight of foundations. This also includes the mass of furniture, people, equipment (all together the payload) and snow. To obtain an accurate value, loads are collected.

The load from a building is most often calculated per linear meter of walls. It practically does not depend on the size of the building in plan. The number of floors of an object has a strong influence.

What foundation to make for a house from foam blocks with your own hands

All of the above factors, based on the requirements of regulatory documents, can be summarized in one table.

When choosing, you need to remember the following points:

• When installing slabs or tapes with high groundwater level, insulation, enhanced waterproofing and drainage must be provided.
• When the water is located at a distance of 0.5 m from the surface or less, piles become the only option. Their sizes and pitch must be selected by calculation. For a two-story building, it will be necessary to install elements of large diameter or with frequent spacing.
• The foundation must be a rigidly connected structure. When using piles and pillars, it is necessary to provide a monolithic reinforced concrete grillage. A belt made from prefabricated blocks requires a monolithic belt along the upper edge (edge).
• If you need to build a house on uneven terrain, the easiest way is to choose piles. If there are insufficient bearing capacity use a recessed slab or strip foundation with a variable base height.

A properly selected foundation for a foam concrete house will prevent the occurrence of mother-in-law, sediment and other problems during operation.

Advice! If you need contractors, there is a very convenient service for selecting them. Just submit in the form below detailed description work that needs to be done and offers will be sent to your email with prices ranging from construction crews and companies. You can see reviews about each of them and photographs with examples of work. It's FREE and there's no obligation.

Buildings from artificial stone, and in particular from foam blocks, occupy a huge segment of the individual market housing construction. This is a lightweight and heat-resistant material, characterized by low cost and durability. When designing foundations for walls built from foam blocks, one should take into account not only the general conditions, but also the characteristic features of this material. This is an empirical value that depends on many factors, and careful preparation is necessary to determine it correctly.

Choosing a foundation type

Since construction made from foam blocks is almost fifty percent lighter than stone one-story house with walls of similar thickness, the load-bearing capacity of the foundations, and therefore the amount of work and the estimated cost of the supporting structure, will be significantly lower. The minimum thickness of a foam block wall without cladding is 300 mm, and if it is not intended to line the house with bricks, the width of the foundation can be taken in accordance with the transverse size of the foam blocks.

Depending on the type of soil, an appropriate foundation should be selected. For slightly heaving and non-subsidence soils, it is rational to use strip foundations, since it is enough to lay the base of the foundation slab below the freezing mark. Waterlogged, weak soils require deeper laying of supports, and pile foundations successfully cope with the task within a reasonable budget.

When constructing pile foundations, it is necessary to take into account the installation features of the strapping structure. Pile foundations can be installed under walls made of foam blocks, with both low and high grillages. To install a grillage on the heads of metal piles, you should use reinforced concrete and rolled steel profiles, since it is not recommended to support walls made of foam blocks on wooden frames, as well as an unreinforced metal profile.

In addition, it is easier to lay a waterproofing layer on concrete.

Calculation of depth

The initial parameter for determining the laying depth is the level of soil freezing. Strip foundations must be laid at least half a meter below this level.

Since it is impossible to completely eliminate the impact of frost heaving, its impact at least on the sole of the supporting structure is avoided. It makes no sense to lay pile foundations less than two meters deep.

Of course, if one-story house has insignificant mass, you can use a structure made of screw piles, the depth of which can be from one meter.

If we do not take into account non-buried and shallow foundations, the depth of support structures is always determined taking into account the lower freezing mark of soils according to the following scheme.

Load collection

The next stage in calculating the parameters of the support, after geological exploration. Regardless of the type of supporting structure, you need to calculate the total mass of a house made of foam blocks in order to then estimate the load on the foundation structures. This parameter directly depends on the materials used in the construction of structures resting on the upper edge of the base.

Loads acting on the supporting part of a one-story house are divided into temporary and permanent. The permanent ones include:

• Loads from walls and partitions made of foam blocks;
• Loads from floors - basement, interfloor and attic;
• Roof loads;
• Payload - depending on the operating group of the house.

To determine each of the above indicators, you need to know the volume of the structure and the density of the materials from which it is made. The density of foam blocks varies in the range of 100-1200 kg/cm3 depending on the strength brand. You can calculate the volume of walls by multiplying the length, height of the wall and width of the masonry - there is no need to subtract window and door openings from the volume, since their weight is insignificant. By multiplying the volume and density, the load exerted by the walls on the foundation slab is determined.

The weight of the floors is calculated in a similar way - the area of ​​the floor is multiplied by the thickness and density of the material. For example, 1800-2500 kg/cm3 for reinforced concrete or 600-900 kg/cm3 for wood. The mass of roofing structures is calculated for one square meter, and then multiplied by the total coverage area. Usually one square finished roof made from metal tiles weighs about 70 kg, from rolled roofing – 80 kg. It is better not to rely on chance, but to check information about the mass of the material with the manufacturer or on the Internet. All calculated structures are multiplied by the load reliability coefficient, which is taken from SP 20.13330.2011.

Live loads are determined in accordance with the instructions of SP 20.13330.2011. These include wind, snow (depending on the region), as well as loads from equipment. The climatic region can be determined using the table located in the above SP or in regulatory documents in construction climatology. The end of the calculation will be the summation of temporary and permanent loads.

Watch the video on how to correctly take into account all the loads when designing the foundation of a house.

If you divide the obtained value by the length of the perimeter, you can find out the load value per linear meter of the foundation - which is important when designing, for example, pile foundation structures. After the soil has been analyzed and the loads have been collected, we begin to calculate the bearing capacity of the foundation, the sequence of which depends on the type of support.

Strip foundation

The bearing capacity of a strip foundation depends on the depth of its foundation and vice versa. The determining factor for the cost of the structure is this dependence of the geometric parameters of the foundation slab on the load limit that the foundation can withstand. The strength of the tape is calculated according to the following scheme:

• Calculate the total area of ​​the foundation base - for this, the perimeter along midline multiplied by the width of the base of the foundation slab;
• Divide the total load by the resulting area;
• The value indicating the mass of the house per linear meter of the foundation slab is compared with the calculated resistance - the first value should not exceed the second.

Also, data on soil resistance and other quantities used in the calculation can be found in SNiP 2.02.01-83*. The depth of the tape will influence in which soil layer the supporting part of the foundation is located, and therefore what soil resistance should be used in the calculation. The depth of soil freezing is another determining factor when designing the belt - the lower elevation of the foundation should be half a meter below this value.

Pile foundation

Pile foundations are calculated without taking into account the dimensions of the grillage, so the laying depth is measured from the top edge of the pile pillar. The calculation of the depth of piles is carried out in the following order:

• The pile depth L is assumed to be equal to n meters;
• The bearing capacity of the pile is calculated using the formula:

P – load-bearing capacity limit; Rg – relative soil resistance, an example of calculation of which is in SNiP 2.02.01-83*; D – cross-sectional area of ​​the pile; Eycf, fi and hi – coefficients from the above SNiP; x is the length of the cross section of the pile divided by the length value.

• Compare the load limit of the pile with the weight of the house per linear meter of foundation;
• If the load is within acceptable limits, the calculation is completed; if not, one of the geometric parameters of the pile is increased.

Both piles made of monolithic reinforced concrete and metal screw pile columns are suitable for this calculation. The depth of the foundations for a one-story house made of foam blocks does not play a special role when using other types of foundations, for example, columnar or shallow foundations.