How deep should the foundation be for a one-story brick house?

The underground foundation of a building is the most significant and important structural element. The service life of the building, its thermal insulation characteristics, the level of indoor humidity and a healthy atmosphere depend on how correctly the calculations were made and how carefully the technologies were followed when laying the foundation.

Despite the apparent simplicity of the issue, the foundation for a one-story house must be carried out in strict accordance with design calculations and the use of design materials.

Factors affecting burial depth

The depth of placement depends on the type of soil, the mass of the structure

To determine how deep the foundation should be, it is necessary to study the operating conditions of the future structure. Calculation of the technical characteristics of the base is made after:

• work was carried out to study the soil at the construction site;
• the landscape has been studied or a construction spot has been cleared;
• a building plan has been drawn up, defining the area, weight of walls and ceilings.

At the stage of studying and collecting data about the location of the future building and the quality of the soil, the following parameters must be determined:

• soil type;
• average annual precipitation;
• groundwater level;
• depth of soil freezing;
• altitude differences in the terrain of the site.

Taking into account the design features of the house, its weight, the presence or absence of an underground or basement floor, they choose the type of foundation and calculate the depth to which to dig the foundation for the house.

Depending on climatic conditions, the size of the trench will vary.

The colder it is, the more seriously you need to approach the issue of installing the foundation.

The depth of the foundation is always greater than the level of soil freezing: in southern latitudes a depth of 60 cm is sufficient, in northern regions it will be necessary to go at least 1.5 m deep.

Construction stages

The first stage of construction is marking the site, strictly according to the drawing of the future foundation. Marking is carried out using pegs with string stretched over them.

Next - earthworks . The depth and width of the trench should be 15-20 cm greater than the base parameters - this is necessary for arranging a cushion, installing formwork, and bedding.

The third stage is the production of formwork. To simplify the process and make the base warmer and protect it from freezing, you can use permanent formwork made of polystyrene foam.

After installing the formwork, reinforcement is installed in the trench and a cushion of sand or crushed stone is poured. Further:

• pouring concrete,
• its solidification,
• dismantling removable formwork.

The last stage is waterproofing, thermal insulation of the base, if permanent formwork was not used.

Soil definition

There are several ways to determine the type of soil

The type of soil has a significant influence on the depth of the foundation.

To correctly calculate the size of a pit or trench, it is necessary to determine the type of soil at the building site.

The table describes 5 types of soil:

This classification is included in the standards for checking the stability of underground foundations.

The degree of frost heaving is determined based on the level of natural soil moisture and the position of groundwater during the period when freezing begins.

The depth of the foundation for a garage, gazebo or other light building on heaving soils should be calculated especially carefully. If the depth level is insufficient or there is an error in the thickness of the base, soil with a high degree of frost heaving will squeeze the base out of the ground during the freezing period.

Optimal distance for various buildings

You cannot rely only on the size or purpose of buildings, since in addition to the weight of the house, the type of soil plays an important role.
The denser the underlying layers, the smaller the width of the tape can be made during construction.

For auxiliary and utility buildings, the width of the tape is allowed:

• Dense (rocky) soil, clay - 25 cm.
• Loam - 30 cm.
• Sand, sandy loam - 35 cm.
• Soft compacted sand - 40 cm.
• Very soft sand - 45 cm.

For one-story light houses (dacha, frame house):

• Dense (rocky) soil, clay - 30 cm.
• Loam - 35 cm.
• Sand, sandy loam - 40 cm.
• Soft compacted sand - 45 cm.
• Very soft sand - 50 cm.

For two-story cottages:

• Dense soil - 50 cm.
• Loam - 60 cm.
• Other types of soils do not have average indicators and require separate specialized calculations.

It must be borne in mind that average values ​​are rarely suitable for specific situations, since there are always a lot of additional factors not taken into account in the tables.

The impact of these factors can radically change operating conditions and require a separate calculation, sometimes made using a completely different methodology.

Terrain and types of foundations

For large differences in height, it is recommended to choose a pile or mixed foundation

In addition to the type of soil, it is important to understand both the evenness and uniformity of the topography on the building site. Sites with a slope must be leveled.

If it is not possible to level, then the minimum foundation depth is calculated taking into account the lowest point, and if large elevation differences are observed in the area, then the type of foundation is selected either mixed or pile.

In practice, there are 4 main types of building structure:

• columnar,
• pile,
• tape,
• slab.

Columnar base

This type of base is good for use on a small budget.

Pillars as a foundation for a house are the most budget-friendly solution, so they are often used for garage construction or for a one-story country house.

They are made from blocks, bricks or by pouring into formwork. Thanks to the use of technological materials, this type of base is time-consuming.

Waterproofing and a sand cushion are laid at the base of each pillar. Supporting elements are placed in places of the greatest vertical load: the corners of the house and the intersection of load-bearing walls of the structure. It is very important that the pillars are strictly vertical. With this type of foundation, the depth of the foundation for a one-story brick house is no more than 0.8 m, of which 30 cm is the cushion and waterproofing, and 0.5 m is the height of the pillar.

Calculation of the amount of concrete, wire and reinforcement

Having decided on the size of the foundation, we need to calculate how much reinforcement, wire and concrete we will need.

With the last one everything is simple. The volume of concrete is equal to the volume of the foundation, which we already found when we calculated the load on the ground.

But what metal to use for reinforcement has not yet been decided. It all depends on the type of base.

Reinforcement in strip base

For this type of foundation, only two reinforcement belts and reinforcement up to 12 mm thick are used.
Horizontal longitudinal reinforcement bars are subject to greater loads than vertical or transverse ones. Therefore, ribbed reinforcement is placed horizontally, and smooth reinforcement is placed vertically.

The length of the ribbed reinforcement can be easily calculated by multiplying the total length of the base by the number of rows of rods. If the foundation is narrow (40 cm), two longitudinal rods for each belt are sufficient. Otherwise, the amount of reinforcement in the belt will have to be increased.

Transverse rods are installed every 0.5 m, retreating 5-10 cm from the edge of the foundation. We determine the number of connections by dividing the entire length of the foundation by 0.5 (the step between intersections) and adding 1.

To find the length of smooth reinforcement required for one intersection, we use the formula:

(ShF - 2*ot)*2 + (VF - 2*ot)*P, where ShF and VF are the width and height of the foundation, from is the offset from the edge of the foundation, P is the number of rows of reinforcement in the belt.

the amount of smooth reinforcement required for the foundation

The cost of binding wire for the foundation is the product of the wire consumption for one bundle (30 cm), the number of bundles at one intersection (equal to the number of rows of reinforcement multiplied by 4) and the number of connections.

Reinforcement in slab foundation

For a slab base, ribbed reinforcement with a thickness of 10 mm or more is used, laying it in a grid, in increments of 20 cm.

That is, for two reinforcement belts you will need:

2*(ShF*(DF/0.2+1) + DF*(SF/0.2+1)) m reinforcement, where ShF is the width, DF is the length of the foundation.

connect the intersection of the upper grid with the corresponding intersection of the lower one

Taking into account the thickness of the slab and the distance of the frame from the surface of the slab, we determine the amount of reinforcement required to connect the belts using the formula:

((DF/0.2+1)*(SF/0.2+1))*(TP-2*from), where TP is the thickness of the slab, from is the distance from the surface.

how much reinforcement is needed for a slab foundation

The length of the knitting wire is calculated based on the formula:

(DF/0.2+1)*(SF/0.2+1)*4*0.3

Piles

It is especially recommended to use piles on northern heaving soils

What is a pile foundation? When constructing this base, metal pipes with a blade at the end are screwed into the ground like self-tapping screws. Piles simultaneously support the building and distribute the load on the ground from the weight of the structure. The blade at the end of the pile prevents the structure from being squeezed out of the soil during freezing and heaving.

Such a foundation arrangement is especially relevant in the northern regions, where, due to climatic conditions and during winter freezing, the issue of squeezing out the foundations of light buildings and structures by heaving forces arises. In such conditions, piles are suitable both as a foundation for a garage and as a foundation for a one-story brick house.

For light buildings, metal bladed piles are used

How to determine the depth of foundation on piles? The depth of freezing is determined by the trenching method. The drill is screwed in to such a depth that the blades are below the freezing level in dense layers of soil.

The piles can withstand a tensile load of up to 330 Pa. In this case, the maximum pressure force during heaving is 0.2 Pa.

Metal blade piles are suitable for the construction of lightweight buildings. The technology of bored piles has been developed for heavy buildings.

The great advantage of such a foundation is that work on its construction can be carried out at any time of the year in any climatic conditions.

Video description

What types of foundation are there? How is the foundation built and how much does it cost? See all this and much more in this issue:

Scheme of a deep foundation Source kamtehnopark.ru

Sometimes there is a need to strengthen the foundation of a brick house. This can be done in a variety of ways, including:

• Strengthening by injections . The soil around the base is removed, and a cement solution is applied to the exposed base (special equipment is used).
• Reinforcement with piles . Piles are installed along the foundation.
• Reinforcement with reinforced concrete cage . Formwork is installed around the perimeter, a reinforcing belt is installed and concrete mixture is poured.
• Reinforcement with a protective wall . The outer wall is made of concrete, sometimes it rises to a height of up to one meter.

Reinforcement with reinforced concrete slab Source pallazzo.su

Strip foundation

The strip foundation design is a monolithic, solid, inextricable concrete pour, usually with internal reinforcement.

The foundation is placed under all walls of the building, including partitions that carry vertical loads. Along the perimeter, the base has the same cross-sectional dimensions.

The foundation strip forms a continuous contour

Depending on the type of soil and the mass of the building, various shapes are poured:

• rectangular;
• trapezoidal;
• T-shaped.

The integrity and continuity of the base contour ensures uniform distribution of vertical and horizontal loads. This explains the strength, reliability and demand for this type of foundation. In addition to the shape of the base, it is important to determine at what depth to make a monolithic strip foundation. For a detailed presentation on strip foundation construction technologies, watch this video:

Shallow design is not suitable for heavy buildings

Depending on the weight of the building, the level of soil freezing, the location of groundwater and the type of soil, the depth and types of strip foundations can be different:

• shallow with a depth of no more than 0.6 m. The device is supposed to have a movable base, subject to soil heaving. Not suitable as a basis for the construction of heavy buildings;
• buried - a reinforced concrete monolithic frame laid below the freezing level of the soil. Used for buildings with basements that have a large mass.

It can be generalized that the recommended strip foundation and laying depth depend on the weight of the building and the type of soil heaving.

Advantages and disadvantages of LF, operating conditions

It is not difficult to understand why the strip foundation is so named - everything is clear from its geometry. The base is a reinforced concrete strip, which is built around the perimeter of the future house.

The tape exactly repeats the layout of the house, including the bay window, internal load-bearing walls, veranda, and so on. Due to this design, the foundation evenly distributes the load from the walls.

A traditional strip foundation is built from concrete, which is poured into prepared formwork. The tape must be reinforced with metal rods, creating a lattice from them.

Due to the device, such a base has many advantages:

1. 
   A simple design that does not require heavy equipment for construction - ordinary tools are enough to do all the excavation work, make formwork and concrete mortar, right on the site.

2. Relatively low cost - due to the small footprint compared to a slab foundation, for example.
3. The ability to withstand high loads - on such a foundation you can build a two-story brick house.
4. Frost resistance.
5. Possibility of construction without the involvement of work crews.
6. Fast construction.

But the strip foundation also has certain disadvantages. First of all, it is only suitable for dense, non-heaving soils.

If the soil is heaving, it is possible to build a strip foundation, but its depth and width of the base will be much greater, which complicates the construction. If the soil has weak bearing capacity, a strip base is not suitable .

The second, relative disadvantage is its own large mass, to which is added the weight of the house. If calculated incorrectly, this leads to subsidence of the building.

Plate

Slab foundations can be installed on any type of soil

Like tape, a monolithic slab can be recessed or not. In the first case, the slab is poured into a pit and has high ribs. The main disadvantage of such a device is its high cost. But this is the only type of foundation that has no restrictions on the type of soil.

How to calculate the laying depth, and what should the slab be? The heaving of the soil does not affect the condition of the building on this basis, therefore this distance is determined based on the operational requirements for the building. For more information about building the foundation, watch this video:

The monolithic slab is a floating solid foundation and its installation is possible even on swampy or peaty soils, where the groundwater level is quite high.

The summary table shows the types of foundations, soil types and weight of the structure

Mistakes and mistakes

The main mistake is neglecting accurate calculations, using average numbers and foundation parameters “like your neighbor’s.”
If you cannot calculate the depth and width of the tape yourself, contact a professional, but you cannot build a building without an accurate calculation.

The second mistake is saving on the quality of materials . It leads to deterioration of the characteristics of the foundation, and this will affect the reliability of the entire house.

Third, neglect of geological research. There is a big difference in bearing capacity between soil types, and the type and parameters of the foundation directly depend on it. There is no room for error here.

Recommendations for calculations

In case of mass construction, the calculation of the depth of construction is carried out by specialists at design institutes. More often, during individual self-development, the question arises: how to calculate the foundation for a garage, bathhouse or one-story cottage?

After receiving all the necessary data on the soil and the weight of the building, a final calculation is performed and the depth of the foundation is determined.

The depth, although within the same limits, will nevertheless always be different. On the same site, the foundation for a one-story or two-story brick house will differ significantly.

Each calculation is purely individual. If it is not possible to contact specialists, you can enter the data into an online calculator and find out the recommended dimensions adjusted for freezing depth. For more information on calculations, watch this useful video:

But there are a few general guidelines to follow:

1. Any foundation is laid below the soil freezing level by 10%. If the freezing value is set to 70 cm, then the depth of the hole under the base should be 77 cm.
2. For loose soils in temperate climates, it is better to use a strip base with a laying depth of 0.5 to 1 m.
3. In the northern regions with slightly heaving soils, a foundation buried up to 2 m is made.
4. In swampy areas or on clay, a slab would be an ideal option, and the depth of burial can reach 2.5 m, which allows you to make a basement.

The basic rule when calculating the foundation: a competent and reliable foundation is the key to a long service life of the building. It is worth noting that overdoing construction is also fraught with consequences, as is saving. A pit dug below the required level will not make the house more reliable, but will increase the consumption of materials and the area that will be negatively affected by soil and groundwater.

The foundation of a house is one of the most important elements of its design. The future reliability and convenience of the entire building depends on it. As a solution to most construction issues, the depth of the foundation for a one-story house should be based on strict compliance with the design documentation, the characteristics of the materials used, the economic feasibility and budget of the developer. The quality of the soil, climatic conditions and other important factors are also of great importance.

Dependence on groundwater level

Underground springs, which are located in the upper layer of the earth, oversaturate the soil with moisture and gradually destroy the integrity of the reinforced concrete foundation. This factor must be taken into account when designing the foundation. The developer can hire a surveyor to perform a hydrogeological analysis or do the research themselves.

Deep occurrence of hot water

When groundwater passes below the frost line, the house is practically unaffected by it. The defining dimensions in this case are calculated only taking into account the geology of the site and the weight of the structure.

Above or at the level of the frost line

For the developer, such hydrogeological conditions are considered unfavorable and require compensatory measures. To avoid destructive effects, the tape is lowered below the frost line by 0.15 - 0.2 m.

Such a foundation should be classified as a buried type. Several layers of waterproofing are prudently laid between its layers.

Rocky, coarse-grained, gravel and similar rocks are dense enough that the engineer does not have to take into account the occurrence of sources in the calculations.

What affects the depth of the foundation?

Determining the depth of the foundation approximately or “by eye” is unacceptable even for the simplest structure. Competent and accurate calculations are required, based on the characteristics of the building itself and the environment. To do this, the following must be taken into account:

1- level of soil freezing;

2- soil quality and depth of its layers;

3- location of groundwater;

4- the presence under the foundation of a cushion of sand and gravel 10-30 cm thick (this value must be taken into account when digging a trench);

5- design features of the house (presence of a basement, ground floor);

6 - total load on the foundation;

7- weather and other external conditions;

8 - selected foundation type;

9- budget allocated for the construction of underground structures.

The level of freezing varies in different regions. So, in warm climates, a depth of 0.6 m will be sufficient, but in areas with harsher winters, the foundation will have to be deepened by at least 1.5 m.

Determination of basic soil parameters

The main soil parameters on which the depth of the foundation depends include the type of soil, the level of freezing and groundwater flow, and the terrain.

Determining the soil type

To calculate the depth, you need to find out what type of soil is located under the future house. Soils are:

• heaving (clayey, loamy)
• slightly heaving (mixed)
• non-heaving (rocks, sand).

To find out the type of soil, you need to provide a sample of it to specialists. Based on the result obtained, initial calculations can be made. The most reliable are non-heaving soils, since they can withstand any load. The optimal foundation depth for a one-story house on such soils is 0.5-1 m. On mixed soils, it is recommended to deepen the foundation by 0.8-1.3 m, on heaving soils - by 1.3-1.8 m.

Determination of groundwater and freezing level

To find out the groundwater level, you can also contact the relevant specialists or determine it yourself by digging special wells - pits - at the site of the future house.

They need to be deepened by 2-2.5 meters, which makes it possible to establish both the presence of groundwater and the depth of soil freezing.

Taking into account the terrain

In addition to the specified soil parameters, it is also necessary to take into account the terrain. The easiest way to lay the foundation is on a flat surface. And the area with a slope must be leveled as much as possible or left as it is, but the calculation of the depth should be carried out from the lowest point.

Based on the results of the soil study, the appropriate type of future foundation is selected.

Pile type devices.

The use of a pile or pillar structure is most suitable for soil with a fragile or excessively heaving surface.

The columnar foundation design, which includes wide support soles with a drilling device, is very popular.

Such a foundation has one main drawback - its construction requires the use of specialized equipment. The design is well suited for the construction of one-story buildings and all kinds of extensions.

When building a foundation for a brick house with your own hands, which has a pile structure. The following instructions must be followed:

• First, you should clean and mark the area. Check the compliance of the base angles with the specified values;
• Determine the places where the supports will be located;
• Remove soil from the marked areas;
• Drill wells;
• Carry out the manufacture of a frame from reinforcement. Its height should exceed the ground level by 30 cm;
• Pour the sand and gravel mixture into the well recesses;
• Install the frame into the holes for the wells and fill it with concrete mortar.

It will take 4 weeks for the base to harden. When pouring a base of piles, the use of formwork will be required. The material can be simple boards or plywood covering.

Foundation options for a one-story house

One-story houses are erected on a strip, slab or column-pile foundation. Columnar and shallow strip foundations are suitable for the lightest buildings. On heaving soils, slab and pile foundations are preferable.

1. Strip foundations

There are two types of such foundation:

• shallow - the maximum depth of the foundation for a one-story house is 60 cm. This means a floating foundation, subject to heaving phenomena in the soil, which is located under the base of the foundation. This solution is not suitable for massive buildings with heavy weight;
• recessed - made in the form of a monolithic reinforced concrete strip laid below the freezing level of the soil. This option is used for houses with heavy structures.

2. Column-pile foundations

The simplest columnar foundations are usually used only for very light buildings. More massive buildings require the installation of bored or screw pile foundations.

3. Monolithic slabs

This option is suitable for most cases and involves laying a monolithic slab with pouring into a pit or even without penetration into the ground. The main disadvantage of such a foundation is its very high cost.

Average values ​​for different types of buildings

Another indicator that should be taken into account when calculating is soil resistance. For the main types of soil it is as follows

• dry dense clay – 1.6-3.0;
• coarse sand – 3.6-4.6;
• medium-grained – 2.5-3.6;
• fine-grained – 2.2-3.4;
• sandy loam – 2.6-3.6;
• loam – 1.6-3.0;
• gravel, crushed stone, pebbles – 5.1-6.5.

After this, you need to determine the weight pressure of the building. For main building structures these indicators are as follows (in kg/cm2):

• plank walls with insulation – 30-50;
• log – 80-120;
• expanded clay concrete – 460-580;
• brick – 570-970;
• overlap on wooden beams – 120-160;
• basement – ​​170-300;
• reinforced concrete – 320-550.

By calculating the weight of the building and comparing the result with the calculated soil resistance, you can determine whether a strip foundation is suitable for your building. It also happens that you have to think about how to make the building lighter or choose a different type of foundation. We provided a complete example of calculating a strip foundation here.

Recommendations for calculating foundation depth

After the final determination of the soil parameters and type of foundation, a final calculation is performed, based on the results of which the optimal foundation depth for a one-story house is established.

This calculation is strictly individual, but its implementation requires compliance with the following recommendations:

• Any foundation should be laid 10% below the soil freezing level. So, when the soil freezes to 100 cm, the trench should have a depth of 110 cm.
• On loose soils in a temperate climate zone, it would be most advisable to lay a shallow strip foundation (monolithic with poured mortar or prefabricated with ready-made blocks). On average, such a base has a depth of 45 - 100 cm.
• For mixed, slightly heaving soil in harsher winter latitudes, a foundation deepened by 1-2 meters is more suitable.
• For a one-story brick house, the best option would be a recessed strip foundation with reinforcing pillars.
• In clayey or swampy areas, even under a house with a lightweight structure, it is necessary to lay a monolithic slab foundation with piles. The depth of such a foundation can reach 2.5 meters.

Many developers prefer to solve various construction problems, guided by the “in reserve” principle. In other words, if, in accordance with all calculations, the sufficient depth of the foundation for a one-story house is 1 m, in reality, to prevent possible problems, a trench of 1.5 m is dug. Such a precaution only entails unnecessary costs.

In most regions, weather and all other natural conditions have not changed for thousands of years. Therefore, no unforeseen changes will happen in this regard. Therefore, even small deviations from established standards will be completely unjustified. If the calculation is done correctly, no “reserves” are required.

The main rule for determining the parameters of the foundation is the following: the more competently the foundation is built, the less the house will be exposed to negative factors.

Foundation depth for a one-story house

Today, do-it-yourself construction of a variety of non-residential buildings, as well as houses and country cottages, has become widespread.

Building a house has some difficulties due to many parameters that must be taken into account before planning the foundation; how long the house will last depends on them.

Laying the foundation is the most important part of construction, and its depth determines the strength of the entire further structure.

Device.

The installation of each foundation for a brick house is carried out in accordance with the requirements of SNiP and the capabilities of the contractor. Let's look at step-by-step instructions for different carrier systems.

Monolithic foundation for a brick house :

1. First of all, a project is prepared. The documentation takes into account the terrain features, geodesy requirements and other parameters that affect the durability of the structure. Drawings are being prepared according to which the territory will be marked;
2. A trench is dug along the marked lines; it is especially important to ensure that the corners are even. Otherwise, the support will “float” and the building will begin to collapse prematurely - 5–7 years after completion of construction;
3. The depth of the pit should be 20 centimeters greater than required, since a sand or crushed stone cushion is taken into account;
4. Fine crushed stone or sifted sand is poured onto the leveled surface of the base, and the embankment is compacted. After this, a thin layer of concrete is poured onto the pad. It is recommended to discuss its dimensions with a specialist, since parameters for different objects may vary;
5. To build such a structure, it is necessary to additionally insulate and isolate the slab from moisture, so a waterproofing film is laid over the pouring;
6. Along the entire perimeter of the future pouring, it is necessary to install formwork that will prevent the solution from spreading;

Reinforcement of a foundation slab for a brick house.

• For the construction of that system, the presence of a reinforcing belt is also very important. To create it, the reinforcement is cut into equal sections and installed over the entire area of ​​the base. It welds together. It is acceptable for the ends of the rods to protrude 5–10 centimeters from the solution;
• All that remains is to fill the support and cover it with film to harden (so that dew and rain do not damage the solution).

In terms of the construction process, a strip foundation for a classic brick house is very similar to a monolithic one, with the exception of pouring the entire area of ​​the building. To create it, it is enough to lay the solution only around the perimeter of the building.

1. The area is marked and cleared of various debris, stones and trees;
2. Trenches of the required width and depth are dug using an excavator or manually. These parameters must be clarified in advance with surveyors in your region;

Marking a strip foundation for a brick house.

• The thickness of the sand cushion is 20 cm, this parameter is taken into account when preparing the trench. Make sure that only fine crushed stone or sifted river sand is used;
• Similar to a monolith, you will need to equip the foundation with waterproofing. To do this, film, roofing felt or other available materials are laid at the bottom of the trench;
• Next, the base is reinforced. Metal rods are installed in the centers of the corners and welded together. They are connected to each other, forming a metal belt around the perimeter;

What kind of foundation is there for a brick house?

• Depending on the chosen technology, you can fill the entire tape with a clean solution or first lay blocks in it and then treat it with the solution;

Options for installing a strip foundation for a brick house.

• After pouring, you need to wait about a week for complete hardening.

Strip foundation for a one-story brick house.
Bored and pile foundations are used when any other is not suitable. It is universal, quickly installed and can withstand fairly heavy loads. The structure consists of separate supports (piles), which are connected to each other by a grillage (concrete strip). But, despite the fact that the foundation itself is very cheap, to build it requires the use of special drills that will make holes in the ground for the columns. This construction process is carried out only by professionals and accounts for more than half of the estimate for the entire construction.

1. The site is prepared and marked. Piles are necessarily placed at every angle and intersection of walls, but they can be installed more often for greater rigidity of the building. For example, at each center of the wall;

Columnar foundation with grillage.

• Next, holes are drilled. An important feature is that the hole in the ground should be smaller in diameter than the pipe. If the width is slightly larger or matches the piles, the base may become loose;

  
  Drawing of a foundation support for a brick house.

• The bottom of the holes is compacted with a cushion of crushed stone and sand, the average size is up to 20 cm;
• A metal reinforcing belt is installed in each hole. It is made from reinforcing bars welded together;

Approximate dimensions of the foundation for the house.

• A pipe is installed on top of the resulting mesh. It will be filled with cement regardless of whether a monolithic structure or a bored one is used, therefore, so that it can be raised after completion of the work, it is lubricated inside with oil or other solution;
• A stone, rubble, crushed stone is thrown into the pipe, or a solution is simply poured. Due to its small area, its hardening time is much faster than that of tape or monolith;
• The pipes are removed and formwork is placed on top of the pillars. Filling and reinforcement are carried out in the same way as when installing a strip foundation for a brick house.

Recommendation: A good review article, from it you will learn the general concept of a strip foundation for a brick house. Pay special attention to the soil and weight of the house; if there is an imbalance, the house will shrink and you will lose money. We kindly ask you to be extremely careful.

What determines the choice of depth?

For any building, the depth cannot be simply determined by eye; many calculations are needed here, and first of all you need to pay attention to:

• groundwater flow level;
• climatic features of the area in which the house will be located;
• soil freezing depth;
• total building load and construction materials;
• selected foundation type.

The first thing you need to know when calculating the depth of the foundation is that it must be laid below the freezing level of the ground so that the foundation does not deteriorate due to repeated freezing and thawing.

It should also be located above the level of groundwater flow, which is a strong destructive force for the foundation.

An example of a finished structure for a one-story house without a basement is presented below.

Types and varieties of soils

When calculating the depth, you need to immediately find out which soil will be under the foundation of your house. They are:

• heaving, that is, clay, loam, sandy loam;
• non-heaving: sand, rocks;
• slightly heaving soils - various mixtures.

The most optimal soil for construction is non-heaving soil, as it is durable and can withstand any load. You can see an example of such soil below.

You can find out such data by contacting specialists and taking a soil sample from the site.

Non-heaving soil

In accordance with the data obtained, the first calculations can be made, following which the optimal depth for non-heaving soils will be 0.5-1 meter.

For clayey soils - 1.2-1.5 meters, for mixed soils - from 0.5 to 1.25 meters, depending on how mobile the soil is and what percentage of the heaving mixture it contains.

Determination of groundwater level

In determining the second parameter, you can also turn to specialists or try to find out this yourself using special wells called shufrs.

They are dug out at the site of future construction, their minimum depth is 2-2.5 meters.

Using such a well, you can determine the depth of soil freezing and the presence or absence of groundwater. An example of such a well is shown in the photo below.

Suffer for determining soil type

The terrain of the site for construction is also important, because it is easier to lay a foundation on a flat surface.

If the site is on a slope, then it will either need to be leveled as much as possible, or when laying the foundation, take the lowest point as the basis for measuring the depth.

After determining the soil and the absence of obvious presence of groundwater, you can think about the type of future foundation.

It also depends on the type of soil whether lateral reinforcement of the walls is necessary so that the foundation does not tilt over time.

What should it be?

The main requirement is strength and resistance to all types of loads . Therefore, concrete of a strength grade of at least 250 is used for the foundation (read more about concrete grades for LF here).

Other materials – crushed stone, sand – should also be of high quality. It is necessary to strictly observe the proportions when composing the concrete mixture, and if you are not confident in your capabilities, it is better to buy ready-made concrete.

Before laying the foundation, a geological study of the site must be carried out. To determine the type of soil and the height of groundwater. These are important factors influencing the parameters of the belt, in particular its depth.

Choosing the type of foundation according to the soil

The foundation itself directly depends on what depth is needed for your construction and on the type of soil being determined.

If it is not heaving, then you can plan a regular strip or columnar foundation, but if the ground is heaving or slightly heaving, then you will have to make a monolithic slab or pile foundation.

Let's consider the main types of foundations for a one-story house, taking into account the depth of foundation:

• Strip foundation, which can be either shallow (for light-weight wooden one-story buildings) or buried. This type is the easiest to install independently and the cheapest. If great depth is not required and the weight of the structure itself is small, then you can choose it.
• Pillars and piles can strengthen a strip or conventional foundation, while for a house that is lighter in weight, it is better to use pillars. If the materials for construction are brick or stone, then it is better to drive in piles that can withstand heavy loads, distributing the entire load-bearing weight over perimeter and deeply strengthened in the ground.
• A monolithic slab can be used in the case of heaving soils and in identifying groundwater.

This design is the most reliable and will withstand any impact and weight, but it will also be expensive and will be difficult to install yourself.

An example of such a plate is shown below.

Monolithic slab - base

Calculation of foundation depth

When you have finally decided on the type of soil and foundation, you can make a final calculation, which will determine the depth of the foundation for a one-story house.

Some try to make the foundation “with a reserve”, that is, to deepen it more than the required level for reliability.

But this will only be an extra financial cost and time-consuming work, and if all calculations are made correctly, then no reserve is required.

Any foundation is laid based on the level of freezing of the ground and is laid 10% lower, that is, if the freezing depth is 1 meter, then it should be laid to a depth of 1.1 meters, this will be enough.

If the climatic conditions in the region of construction are moderate and the soils are loose, then it is most appropriate to lay a shallow strip foundation, which is easy to do with your own hands and will be durable.

It can be either monolithic with a self-filled solution, or prefabricated with ready-made blocks.

By average standards, such a foundation is laid to a depth of 45 cm to 1 meter. Such a foundation looks like the one shown below.

Ready strip foundation

In more severe winter conditions or when the soil mass is heterogeneous, it is better to make a deeper and more reliable foundation, the depth of which can be from 1 meter to 2 meters.

For a one-story house made of ordinary brick, a recessed strip foundation with pillars that will strengthen the entire supporting structure would be quite acceptable.

If the area is swampy or very clayey, then you will have to lay a monolithic slab with piles, even if the structure of the house itself is light.

This will entail considerable financial costs, but you don’t have to worry about the reliability of the design. This foundation can reach a depth of up to 2.5 meters.

Choosing materials for the home taking into account depth

The most economical option these days are wooden one-story country houses, in which you can also make an attic.

When choosing such materials, the house will be quite light and the chance of destruction of the foundation will be minimal, so you can choose a shallow depth and lay the foundation yourself in case of any difficulties.

This building looks like the photo below.

Wooden one-story house

One-story houses made of foam blocks are also easy to build and do not require a large laying depth, but they must be wider, since the wall in such houses should be about 60 cm for heat resistance.

Brick or masonry requires that the laid foundation can withstand a large load, so it is advisable to choose both a large laying depth and reinforcement with piles.

This foundation looks like the image below.

Pile foundation

Considering all these factors, we can say that the depth of the foundation for a one-story house can be very different, but all the above factors should be taken into account for the reliability of the structure.

The main reference point remains the depth of soil freezing, which underlies all calculations of deepening.

Video calculations of the foundation depth of a one-story house

In the next video, experts will tell you what rules must be followed when calculating the depth of the foundation, which will help you correctly determine all the parameters, and you will be able to independently build your house, which will last for a very long time.

The construction of the foundation of a building is an important stage in construction. The strength of the entire structure depends on how correctly the base is laid. To build a reliable and durable foundation for a one-story house, you must be guided by SNiP regulations: 2.02.01-83 “Foundations of buildings and structures” and 23-01-99 “Building climatology”.

How to reduce costs by reducing construction depth?

After conducting a geological survey and all the calculations, it may turn out that the foundation needs to be laid very deep. There are proven techniques that help the developer reduce costs on building materials. All methods are based on reducing the destructive influence of natural factors on the site.

Sole insulation

When the frost line of the soil is shallow below the surface of the earth, the builder, of course, cannot change the climatic conditions in the region. It remains to reduce the significance of this factor by insulating the foundation and the soil adjacent to it. The costs of insulation will be recouped by saving building materials .

Deep drainage

Groundwater lying close to the surface can be drained by installing a reliable drainage system on the site.
Sometimes they make drainage ditches filled with coarse-grained rocks and arrange them in the form of paths. Thus, water will freely wash the monolithic base without destroying it at any ambient temperature.

In areas with high levels of snow cover and heavy rainfall throughout the year, excess water is removed from the base using a deep drainage system. This method involves placing perforated pipes in the ground, covered with fine clastic rocks.

Water is discharged through pipes along the slope of the terrain, and the soil does not become oversaturated with water and does not swell at negative temperatures.

Features of foam block material

Foam concrete blocks are made from cellular concrete by pouring it into special forms. The resulting layers are cut into elements suitable for building houses.

Types of foam blocks

The material is divided into three types depending on density. For private construction the following are relevant:

• structural elements of grades D1000-1200;
• structural and thermal insulation blocks of grades D900-500;
• thermal insulation segments of grades D500-300.

The high density of foam concrete allows the construction of a two-story building with a reinforcing belt.

Properties of building materials

Foam block buildings are becoming relevant for owners of suburban areas. This is facilitated by the properties of the material:

• a unique “breathable” structure, thanks to which sweating of the walls is eliminated;
• the ability to retain heat in winter and provide coolness in summer;
• profitability - due to heat conservation, home heating costs are eliminated;
• good sound insulation;
• environmental cleanliness;
• ease of processing and strength of walls.

Low cost elements based on sand, water, cement and special foam. Small costs for construction consumables allow you to invest more money in arranging a high-quality foundation for your home.

What is the load of foam block buildings?

Compared to buildings made of bricks, foam block buildings are lighter. If a square meter of a brick wall weighs 1.8 tons, then foam blocks have a mass of 0.9. Therefore, it would be inappropriate to construct massive foundations. For a dwelling made of foam block, a monolithic strip, slab or pile base is sufficient. Regardless of the type of foundation, it is worth considering the criteria for its construction and design.

Installation of a slab-type base.

The slab type foundation looks very impressive. It looks like it should require a lot of work. In fact, this type is the easiest to implement.

It is most suitable for soils characterized by severe heaving. Depending on the depth of location, there are several types of foundation structures.

To properly arrange a slab foundation you will need:

• Clean the area, level its surface and mark it;
• Dig a foundation pit. Its dimensions must exceed the dimensions of the base;
• Pour the sand and gravel mixture onto the bottom of the pit and compact it;
• Pour a small amount of concrete (for setting);
• Lay waterproofing in several layers;
• Make formwork. Install spacers and fasteners;
• Connect the mesh for reinforcement;
• Pour the concrete solution at one time;
• Carry out periodic wetting of the base until it sets completely.

Slab-type foundations can be used for various types of buildings. The main advantages of such structures include their large size. As a result, the foundation better resists the load and distributes it between the corner surfaces.

Depth selection: influencing factors

The depth of the foundation for a one-story building is determined through accurate, competent analysis and calculation, taking into account the characteristics of the structure and the environment. The choice of recess is influenced by the following indicators:

• degree of soil freezing;
• climatic features of the region;
• groundwater level;
• quality of the soil surface, occurrence of layers;
• total load of the building;
• availability of design additions (basement, ground floor, garage);
• type of foundation.

Laying the foundation for a house made of expanded clay concrete blocks is carried out above the groundwater level and below the freezing layers. Correct calculations ensure the reliability and durability of the building, the main building material of which is expanded clay block.

Drainage system for a brick house

When the groundwater level is high, to protect strip and slab foundations from erosion, it is necessary to provide a wall drainage system. It is necessary to equip it at the stage of laying the foundation, so as not to carry out excavation work to excavate it again in the future.

Rice. 2.1 : Scheme of wall drainage system

Drainage pipes are located around the perimeter of the house, encircling the contours of the foundation. They are placed 10-20 centimeters below the supporting heel of the base. In the corners of the house, pipes are brought into inspection wells, which are connected to the main storage tank located at the lowest point of the site so that water from the inspection wells flows into the container by gravity. Water is pumped from the main reservoir outside the site.

What influences the choice of base height?

The height of the foundation for a one-story house is set taking into account the following factors:

1. Relief features of the land plot for development. If there are small slopes, the depth of the foundation for a one-story house increases; in areas with seismic activity, additional measures must be taken to increase the stability of structures. The full picture is provided by calculations based on geodetic data.
2. Design features of the building and its purpose. Construction is carried out with or without a basement floor.
3. Level of groundwater passage.
4. The presence of nearby buildings and the type of supporting system used.
5. The composition of the soil, the presence of various voids, bedding in layers and other features.

The ground part of the basement for a house made of timber can rise several meters above the ground, unlike heavy brick buildings.

Varieties and types of soils

When calculating how deep the foundation should be installed for a one-story block house, you should take into account the types of soil. It happens:

• non-heaving – rocks, sand;
• heaving – sandy loam, loam, clay;
• slightly heaving – a varied mixture.

The best type for the construction of residential buildings from expanded clay concrete is considered to be a non-heaving type, characterized by high strength and the ability to withstand various loads. For it, the optimal foundation depth is 0.5 - 1 m, for mixed - 0.5 - 1.25 m, for clay - 1.2-1.5 m, without taking into account other factors.

Preparing a foundation pit and load-bearing cushion for a two-story house.

Strip foundation depth for the house.
Preparing a pit for a two-story building.

Having developed a foundation pit, the bottom is measured using a level and the edge and area are cleared of crumbling soil. Then markings are made for the load-bearing concrete pad. The width of such concrete preparation is 100−1200 mm, with a thickness of 150−250 mm. It can be used to mount both a monolithic foundation and a block one. The formwork is prepared according to the diagram, installed around the perimeter, using reinforcement as stops, simply driving them into the ground.

Reinforcement is done in one tier, with class A 1-3 reinforcement. The mesh cell has a size of 200×200 mm, the joints are knitted with wire. The laying depth of the load-bearing belt is at least 1.8−2.2 meters for medium heaving soils of type 2. What is important when laying is to make a cushion of crushed stone under the base. The thickness of the pillow for a two-story house must be at least 120 mm. Crushed stone is laid on compacted soil. Then water drainage measures are installed or waterproofing material is laid. If construction is frozen for the winter, a pit is dug at the lowest point of the pit to collect water. The size of the sump (storm pit) must be at least 6 cubic meters.

Types of foundations for one-story buildings

The foundation for a house made of blocks is the load-bearing part of the structure. How reliable and durable the house will be depends on its type. For the construction of a block one-story building, 3 technologies for laying a monolithic system are used: a traditional strip base, a columnar structure and a slab system.

Laying depth of strip foundation

For one-story buildings, with heaving soil, the laying depth of the strip foundation is 60 cm for the shallow type. The design resembles load-bearing floating systems lying under the sole and capable of withstanding soil movement. The buried type is performed below the freezing point of the soil. The laying depth reaches 1-1.5 m. A monolithic tape with reinforcement is constructed. This look is typical for the construction of massive brick and block houses. Experienced craftsmen note that the width for the foundation should have a size that exceeds the thickness of the walls by 5-10 cm. This will ensure the reliability and stability of the base of the building.

Pile foundation level

The strength of the building depends on the depth of the base. For the construction of one-story buildings, a pile foundation is often used. The method of constructing foundations using piles gained popularity due to the use of drilled rods. A bored construction is a universal way of arranging a basement floor and has several advantages:

1. Used on terrain with characteristic slopes.
2. Does not require preliminary soil preparation or clearing of the construction site.
3. It is economical. Laying is carried out using a minimum amount of building materials.
4. The pile system is not a continuous structure, which ensures unhindered communication under the building.
5. The construction is carried out without the use of special equipment.
6. The laying of the pile foundation can take place one at a time, in contrast to the strip foundation, where concrete must be poured immediately along the entire perimeter.

What will be the installation depth of the pile foundation - the support for a one-story house built from blocks must be 10-15% below the soil freezing level. This will allow the core structure to easily carry the loads of the building. On heaving soils, to ensure the strength of the system and eliminate structural deformation, the piles are additionally reinforced.

Features of installation of a slab base

The monolithic system is stable and reliable. The slabs are a solid concrete base. To lay them, it is necessary to prepare a pit and clear the construction site. The slab is laid to a depth of 60-100 cm, on a sand and gravel bed. The foundation can withstand heavy loads of buildings.

Shrinkage of brick buildings

Most people are of the mistaken opinion that only wooden structures are at risk of deformation, while brick buildings are free from such problems. In fact, the concept of shrinkage of a brick house is known to all professional builders; This refers to the shrinkage of the foundation. Since the weight of load-bearing walls reaches significant values, shrinkage can also become significant and lead to the appearance of cracks in the walls. The intensity of shrinkage is determined by the properties of the soil - the softer it is, the more the foundation of the house will sink. To reduce negative processes, a cushion is laid under the foundation of the building - a layer of concrete, sand or crushed stone.

Consequences of uneven shrinkage Source stroi-x.com

The period of shrinkage of a brick country house can last for several years (sometimes 5-6 years). To ensure that the process proceeds evenly and does not damage the integrity of the building, the importance of selecting the right foundation becomes obvious. Special technological techniques during the construction of walls also help to avoid cracks. Special expansion joints are left in the brickwork. They last for one to two years and serve as a good preventive measure against the occurrence of not only shrinkage cracks, but also temperature cracks.

After the project has been prepared and a clear understanding of the objective conditions of the construction site has been obtained, the type of foundation is determined. Three types of foundations can support a two-story brick house: strip, pile and slab.

How to calculate the optimal depth for laying a plinth: recommendations from experts

After determining the type of foundation and analyzing the parameters characteristic of a particular area, you should calculate the optimal depth for installing a solid foundation for a one-story building. Each calculation is individual, but its implementation requires compliance with the following recommendations:

• any type of supporting structure is laid on average 10% below the freezing level of the soil layers. For example, the freezing point is 100 cm - the trench is dug at a depth of 110 cm.
• for loose soil in a temperate climate zone, it is recommended to equip a shallow foundation (monolithic or made of blocks). The slab is deepened by an average of 45-100 cm.
• for a weakly heaving mixed group in harsh cold latitudes, a structure is used that is dug in at 1-2 m.
• The foundation for a one-story block house using two laying technologies is characterized by reliability and strength. For example, a strip base with the addition of reinforcing rods.
• For swampy and clayey areas, it is planned to lay a monolithic slab system with piles. The base is installed at a depth of 2.5 m.

Some builders advise constructing the foundation with a “margin”. But this is not always the right decision. Firstly, it will still be necessary to carry out land work, and secondly, financial costs are required. The feasibility of its implementation is excluded on permanent dense soils, with low seismic activity, in temperate climatic zones. To construct a supporting structure for a one-story house, builders often use strip foundations. Other types of bases have gained popularity due to their cost-effectiveness and quick DIY implementation. To build your reliable home, it is better to resort to the use of several technologies in the construction of a durable and strong foundation.

Freezing level.

In the middle zone, ground freezing is not so deep, about 1.5 meters. In the northern regions, the level of freezing is always taken into account; development is carried out taking into account the average temperature over 3-4 years. Everything can be calculated using the formula. We will proceed from it.

Let's look at the notation. The M value shows the average monthly temperature taken in the desired climate zone. The D1 indicator is the depth figure, and D0 is the coefficient of the soil itself. Its limits can vary, from loam and clay 0.23 to rock and clastic rock 0.34. Having finished with the miscalculations, let's begin the process itself.