How many cm from the ground should the house stand. Determination of the height of the above-ground part of the foundation

In the parameters determined during design building structures, includes the height of the foundation, determined from the level of support on the underlying soil (bulk cushion) to the upper plane on which the crown, floor slab or heel of the structure column rests. Separately, the value of the height of the foundation above ground level is taken, which has its own selection criteria. Recommendations for drafting all types of supports, instructions on what requirements the foundation for the house must meet, are contained in SNiP 2.02.01-83 * (edition 2011).

Criterias of choice

In the construction estimate, the height of the foundation will directly affect the cost of the work. Therefore, it is necessary to choose a reasonable balance between the minimum required rise above the ground level and the desired size of the plinth, porch and related structures.

The footprint of the foundation largely depends on the weight of the building, while the level of the foundation above the ground determines the need for protection from environmental conditions (heat loss, preventing moisture from penetrating through the floors).

For each case, it will be necessary to perform a calculation in which the height of the tape-type foundation will significantly affect the total mass of the structure. But the height of the pile foundation above the ground (for example, for a bath) can be chosen based more on the terrain, the height of the snow cover and ease of use.

Different needs in the MZLF insulation scheme, determined by how much their upper mark is above the ground, are shown in the diagram:

In cases where the base is not only a support, but also a space for technical, utility rooms, a cellar or a garage, a qualified design calculation must be performed, taking into account ventilation, waterproofing and insulation of all compartments located in the basement.

high altitude

The total height of the supports consists of 2 components: above-ground and underground parts. Usually most of the stability is located below the surface of the earth. If a high plinth is laid by the project, its above-ground size cannot be more than ½ of the total value.

A high level of groundwater can serve as a limitation on the lower mark. If the groundwater level on the site is lower than 2.5 m, then the foundation will allow you to immediately place a room in its underground part with a height of 1.7 m to 1.9 m, without a high base above the ground. It is necessary to maintain a distance of 0.5 m from the level of the maximum seasonal rise of water in the soil. Useful use the internal volume of the foundation structure greatly increases the scale earthworks, since you need to select the entire soil in the pit and delve into solid bearing rocks.

Do-it-yourself work when constructing a deep foundation can be seen in this photo:

All requirements that a high foundation must meet are set out in SNiP 3.03.01-87, SNiP 3.04.01-87.

Minimum clearance

To protect the walls of the house from the effects of precipitation and soil moisture, the heaving movement of the soil, it is necessary to create a gap between the crown of the house and the ground. It is this goal that meets the height of the foundation above the ground, which is taken at least 0.2 m for MZLF and columnar supports.

If the site has a slope, then this distance in different places can be large.

In the project, based on engineering - geological surveys, the possibility of how much the building can give subsequent shrinkage is laid.

This approach is especially relevant for buildings made of wood - log cabins, baths. In this situation, a sufficiently high base is usually provided on screw piles or columnar supports of the bored type.

It is enough to install light temporary buildings on block linings to create an air gap between the ground and the bottom of the wooden structure, as in this photo:

For special-purpose buildings, the minimum height is determined by the behavior of communications and manholes for inspecting and cleaning the underground.

For example, raising a bathhouse above the ground level makes it possible not only to break the connection with freezing soil and storm flows, but also to achieve a natural runoff of used water through the cracks in the floor.

The necessary ventilation and access to the underground for cleaning is provided by a pile foundation having a height from the zero mark of at least 0.5 m.

Height parameters

In the design calculation, the minimum height above the ground of the building foundation is determined by a complex of factors present. You can display the desired value for the selected type of base, knowing the following parameters:

building materials;
soil characteristics;
the presence of a basement;
snow depth;
groundwater level, storm runoff levels;
freezing depth.

In practice, they rarely observe a minimum of 0.2 m, more often they prudently choose a lifting height of 0.35 m - 0.4 m. In cases where a building is erected on a site with clay soil, the height can reach 0.8 m -0.9 m On sandy soils, 0.5 m is usually sufficient.

The height of the slab foundation, depending on the total weight of the building, will be from 0.2 m to 0.4 m.

In a monolithic MZLF for ventilation, vents are arranged that have installed standard sizes, and this also affects the height of the above-ground part. Water should not flow into them and small rodents should not crawl, so they are located at a level of 20 cm and above.

The location of the level of such openings can be seen in this photo:

The easiest way to maintain the optimal height is to build the base on screw metal piles. It does not require a large amount of excavation, formwork costs and special construction equipment. The pile is screwed in manually. To strengthen the structure, concrete is poured inside.

Each pillar can have a different depth of immersion in order to achieve a sure footing on solid rock layers. The height of the pipe remaining above ground level makes it possible to take into account the terrain and cut all the elements into a single horizon after the entire pile field has been set.

The required rigidity is additionally provided by tying with a grillage, if necessary, scalded with slopes.

Add-ons

For a rough calculation, it is assumed that the cost of the foundation is about 30% of total budget for building a house. You can get savings in the consumption of materials for any type of foundation at the height of the structure above the ground.

Design calculation screw foundation for buildings that are light frames, log cabins, prefabricated panels, it is not very difficult. Works are carried out at any time of the year, on sites of any relief (except for rocky and stony soils). With dense development of the site, without causing damage to nature in the forest or on the banks of the river, small houses for recreation, baths, gazebos, and fences are often placed on screw supports. The construction of a summer house on high pillars makes it possible to use the place under the crown (summer kitchen, car parking) with benefit.

For monolithic solutions, brickwork use a standard of 10 cm of excess snow cover, characteristic of a given climatic region.

How to determine in practice using the water level, what is the actual height difference of a monolithic strip foundation, can be found in this video:

When marking and mounting the support, it should be remembered that the height of the foundation at each of its points must be such that the upper plane has deviations from the horizontal surface no more than permissible values.

The plinth is the outer wall of the foundation, on which the facade rests. At the same time, this is the upper part of the basement walls, if it exists. The height of the plinth depends on the type of base, common project at home, the nature of the soil, the purpose of the basement. There are certain building regulations in this regard.

Some homeowners believe that if there is no basement, then the basement is useless, you can make the foundation flush with the ground.

house design without basement

This is mistake. the main task plinth - isolate the facade from contact with the ground. And so that soil water does not rise from the ground along the concrete in a capillary way, a layer of roofing material is laid between the facade and basement walls.

Base scheme

The plinth must be high enough, regardless of the materials of the facade: wood, foam and cinder concrete, bricks equally suffer from water.

In addition to protecting the walls of the house from destruction, the plinth also solves other problems:

protects the facade from pollution (due to the proximity of the earth, the lower part of the house suffers from them the most);
protects the cladding from mechanical damage (basement cladding is orders of magnitude stronger than facade cladding);
compensates for shrinkage due to the load from the house;
isolates the basement ceiling (most often wooden) from harmful influences;
increases the thermal insulation characteristics of the basement;
gives the appearance of the house aesthetic completeness.
provides its full ventilation (air vents are usually located in the basement of the foundation);

When designing a basement, one should take into account the climate (average temperature in cold weather), the average annual rainfall. You can determine the minimum basement height for your site empirically: measure the depth of the snow cover for several winters and add 10 cm of margin to the average value.

note

The minimum height of the base above the ground according to SNiP for the southern regions is 20 cm (preferably 30-40). If the house is wooden, the distance from the ground is preferably from 50 to 90. If there is a basement, the recommended basement height can reach 2 meters.

A high plinth is more expensive than a low plinth due to the increase in the amount of work on concreting. But in the calculations, savings are in second place, in the first place are strength and performance, which largely depend on the material of the facade.

The height of the plinth is also affected by its position relative to the facade wall. There are three options:

sinking - the plane of the base is recessed inward relative to the facade. It is possible only if the thickness of the facade wall is large enough;

flush with the facade;

speaker. This option is the only one possible if the thickness of the facade walls is small, and also if the project provides for a basement.

The advantages of the third option are increased thermal insulation characteristics ( required property at the device of the operated cellar). In all other cases, the first option is preferable: the overhanging facade wall reliably protects the base from atmospheric factors and mechanical damage. Obviously, the height of the sinking base should be minimal, because. as it increases, the degree of protection decreases.

Foundation options for the height of the basement in a private house

There are design differences for plinths on low foundations (strip, pile-strip, slab) and elevated (pile, column). In the first case, there are no air gaps between the ground and the floor of the first floor, the internal space is completely closed with a concrete or brick strip - either the upper part of the strip foundation, or a superstructure along the perimeter of the slab. In the second case, a gap remains between the ground and the ceiling, the height of which is determined by the height of the above-ground part of the pillars or piles.

basement at the house with a pile foundation

The choice of the type of foundation depends on the characteristics of the soil, topography, and the mass of the building. This issue is resolved at the design stage of the house.

With a low foundation, the basement can be monolithic or prefabricated - from blocks, bricks. The second option involves less protection of the base from harmful factors.

brick basement scheme on a strip foundation

Increased attention is paid to the exterior finish, not so much for aesthetic as for protective reasons. In any case, a blind area is performed (at least to divert atmospheric water from the base), and with a high occurrence of groundwater, a drainage system. The maximum height of such a plinth is limited mainly by economic considerations.

The pile foundation can be low (the grillage lies directly on the ground) or elevated. Columnar, usually elevated. Since it is considered the most unstable, the height must be at least 20 centimeters (to compensate for heaving of the soil). To ensure sufficient thermal insulation of the internal space of the house, the gaps between the pillars / piles are laid with bricks, covered with asbestos-cement slabs or wooden / plywood panels.

an example of basement insulation and piping of a pile-screw foundation

example of internal insulation of the basement of a pile foundation

example of basement insulation outside the pile foundation

example of finishing the plinth of a pile foundation

The maximum height of such a plinth is structurally limited: the above-ground bearing part cannot be too high.

What is the best basement height?

All of the above does not depend on the presence of an operated basement. The basement floor is an important decision in terms of rational space planning in the house and on the site. Suitable for solving almost any task: if desired, you can equip here not only a cellar or a boiler room, but also a study, a home theater, a bedroom. Even taking into account additional costs on the foundation, a large basement height for a one-story house will cost less than a second floor device.

note

Overall Height ground floor(according to SNiP) - at least 2.5 meters. More.

Characteristics of the floor according to the standards:

ceiling height relative to ground level - within two meters;
deepening the basement floor into the ground - no more than half the height of the basement.

The height of the basement floor of your house will also depend on the purpose of the basement. If you are planning to make a bedroom or a room for comfortable rest, it is better to be guided by maximum value; when arranging a utility compartment at ceiling height, you can save (within reasonable limits).

Tags: basement height snip basement ground floor

The base is the bottom outer wall building, which is erected on the ground and plays the role of a barrier between the wall and the destructive effects of atmospheric phenomena. A building without a basement is at risk from mold and rot and is less able to retain heat inside during the cold season. The main condition for a brick base on a strip foundation is high strength. Its structure must withstand the entire mass of the walls of the building. To achieve the required indicator will help high-quality materials with high level resistance to frost, moisture and pressure resistance.

Types of plinth used in construction

To date, there are three options for the basement, which are used in the construction of residential premises:

Exit plinth. From the name you can understand that such a coating goes beyond the outer walls of the house. This kind of basement will be used if they want to achieve additional heat resistance during frost, or if this is required by the style of the building itself, because from an aesthetic point of view this option is more attractive. So that water does not linger on the surface of the base, it is usually equipped with grooves or a drainage system.
The plinth end-to-end with the outer walls has recently been used extremely rarely. This fact is due, first of all, to the absence of any useful properties in this type of base.
The recessed base will be used in the construction of residential buildings. Erected 6 cm deeper than the plane of the outer walls, this type of plinth can save money on organizing water runoff, and also ensure the safety of the waterproofing layer.

What should be the width of the plinth

The dimensions of the basement directly depend on the material from which the walls of the building will be built. Such information is always contained in the general plan and on the project drawing. With walls made of foam block (which is sometimes also called gas silicate brick) with a long surface of 60 cm, a width of 30 cm and a height of 20 cm, the masonry must have a thickness of at least 30 cm.

If further construction involves the equipment of an additional insulating layer on top of the walls, then the width of the plinth should ideally be 38 cm. However, in the case when the brick is used as a decorative element built on top of the walls of foam concrete blocks, the thickness of the plinth increases by another 22 cm, after which it will be at least 60 cm.

Determining the height

Until now, the masters of the construction business do not have an unambiguous answer to the question of what should be the height of the basement. As the level at which the upper point of the masonry should be, it is best to take the height of those that have fallen in a few recent years atmospheric precipitation. This masonry technology is the most reliable and guarantees a long service life for a future building erected on a brick strip foundation.

But in practice, the most common basement masonry with a height equal to the floor of the first floor in the building. This technique also applies to buildings with a basement. Fashion and style trends in our time imply the presence of a high and massive plinth in the house, which are able to highlight the living space, giving it elegance and elegance.

Insulated brick base on a strip foundation

We remind you that all work on the organization of the basement is carried out on the erected tape base.

We outline the corners

One of the most important rules in the construction of not only the base, but any building in general, can be considered the correct definition of the corners of the structure. Negligence in this matter will certainly lead to a curvature of the surface of the walls, which will ultimately lead to their partial or even complete bearing capacity.

Several technologies are used to correctly set the corners, but the following technique is considered the simplest:

At all corners of the base of the building, a row of bricks is laid out without the use of cement mortar. In this case, the planned width of the future structure must be observed. The corners are inserted using the building level.
Next, measure the length and width on both sides, as well as the diagonals. All readings must match to the nearest centimeter. Measurements are carried out using a tape measure or twine.
It does not hurt to check the future walls again for irregularities. To do this, use the same twine.

Base surface waterproofing

In order to ensure reliable protection of the basement masonry from groundwater, care should be taken to organize the upper part of the foundation with an insulating layer, the functions of which can be performed by roofing material folded in half. It is glued to the surface of the base using bituminous mastic, a burner or heated bitumen. Also, glass isol, euroroofing material or an improved type of roofing material, which is based on cardboard - rubemast, is used as a waterproofing layer.

Bricklaying

Having provided the surface of the foundation with a waterproofing layer, you can start laying a brick basement. For fastening the bars, a solution of cement, sand and water is used. When building a basement, only red brick is used without holes and cavities.

They start laying out the base from the corners, placing the rows opposite each other, and covering the surface of the material with a solution 2-2.5 cm thick. After laying out several rows, the surface is checked with a level.

Having reached the minimum height of the base, which is 4 rows of standard bricks, you can begin to build walls. Trim the surface of the basement with decorative stone or siding. It is not uncommon to resort to decorating the basement with finishing tiles. With the help of a basement coating, the strip foundation is leveled with a brick.

If there is a basement floor in the room, holes in the basement for ventilation should be provided. They are located at a height of 10-15 cm from the soil. Dimensions depend on the diameter of the vent pipe. From above, the plinth is covered with a waterproofing layer, the same as the surface of the foundation was covered earlier.

Video about laying bricks on a strip base:

The basement can be a useful room

In the distribution of costs for building a house, the foundation can take up to 30% - 40%, therefore, if you want to save on this part, the minimum height of the base must still be observed, as necessary condition long life of the building. Elevation supporting structure above the ground performs a number of important functions, and it is provided in all types of foundations. A properly made plinth fulfills its tasks, regardless of whether a basement, a cellar is built in it, or it is just pillars sheathed with siding for an easy outbuilding.

Basement tasks

The height of the basement above ground level, when building your own house on your own, often pays less attention than the depth of the foundation. It is not standardized so strictly and is not described in the requirements of GOSTs in such detail.

In the foundation, this part, in addition to transferring the load down to the support, performs 2 tasks of its own:

hydraulic fracturing between soil and walls;
underground ventilation.

An obstacle to the capillary rise of moisture along materials (concrete, brick, wood) is provided by laying waterproofing along the upper plane of the base. The height to which the basement wall is raised protects against water entering the exterior surface of the building in the form of secondary drops, contact snow cover, soil and debris, as shown in this figure:

A clear answer to the question of why it is necessary to observe the minimum required height of the basement above the blind area near the walls of the house shows on practical example specialist in this video:

Insulation

Regardless of, cottage or has several tiers, wooden or brick, the plinth is combined into a single whole with the underground part of the foundation with a heat-insulating and waterproofing coating.

The lifting height above the ground is calculated taking into account the protection of the internal structures of the first floor floor, as shown in this drawing:

V this example the plinth is raised above the zero mark by 0.6 m, since 0.2 m is the thickness of the floor slab. The second component of 0.4 m may be due to the thickness of the snow cover, characteristic of the area and the size of the air, which are located 0.1 m above the snow.

Concrete strip built on with bricks

Monolithic strip foundations to maintain the desired height are often made in a combined (by materials) version. To do this, the above-ground part of the tape with the products is laid out of red burnt brick, as in this photo:

At the same time, one should not unnecessarily arrange a high base (with a margin), as the cost of base insulation increases. Depending on the type constructive solution heat loss from the surface of the protruding base reaches from 10% to 15%. In the case of a high uninsulated basement made of concrete, brick, rubble stone this value can grow up to 40%.

The influence of the blind area

In design solutions for a light or medium weight house, the basement is usually a continuation of an underground support made of the same material. The minimum height above the ground, permitted by SNiP, is 0.2 m. Support belts with a size of 0.4 - 0.7 m work practically effectively. The insulated blind area along the perimeter of the building allows reducing material consumption by reducing the overall height of the foundation.

One of the parameters that determines the depth of the foundation is the depth of freezing of the earth in a given climatic region. The indicator is given in the following reference table:

The total size of the support (tape, pile, pole) in height in the project will be 0.5 m more (standard requirement).

Minimum plinth

To accept a smaller depth of support at home, allows the option of local insulation, mounted under a concrete pavement around the building.

With the appropriate thickness of the insulation, the absence of basements in the construction project in most areas, in order to obtain a stable capital support for the cottage, it can be limited to pouring MZLF with manual digging of trenches and installation of low formwork, as in the following photo:

The concrete blind area protects against the penetration of water from the surface of the earth to the foundation materials, but it is necessary to provide an effective barrier against moisture flowing down the wall down to the basement during rain. It will depend on the selected type of wall and base mate:

Speaker. The basement part of the foundation is wider than the walls and requires an additional installation of a visor along the upper edge, which protects the surface located under it from flowing precipitation. Another function of such a visor is a decorative decoration of the facade of the building.
sinking. The most reliable option, in which the junction of the outer wall and the basement plane is made with a step. Kali break off the edge without wetting the foundation, which increases the safety of operating conditions for the base material in combination with a waterproofing coating. In this type, there is no need to install fenders for drains.
In the same plane with the wall. It is not popular, since it still requires the construction of a protective visor that sticks out on the surface.

In order to understand the need for this measure (protection from water from the walls and its removal along the blind area to the drainage), you can calculate the average number of flowing liters in your area: the average rainfall × wall area × 30%.

Useful plinth

If desired, it is possible to arrange a cellar or a large basement in the underground space of the foundation, if the result of the conducted surveys of the engineering and geological characteristics of the construction site allows.

For specific construction conditions, it is possible to calculate how to equip a useful room even for a private house standing on screw piles, a support in the form of a slab, flooded soils or flood groundwater rises to a mark of less than 2 m from ground level.

SNiP 31-01-2003 of the Russian Federation considers the basement to be a room below ground level at a depth not exceeding 1/2 of its height. The height of the above-ground part cannot exceed 2 m.

Structurally, the device of such a foundation with a basement level differs little from the usual deepening.

The base of the concrete slab view is poured to the calculated depth and walls are erected on it. The tape base is made monolithic or from foundation blocks, its deaf underground part evenly passes into the basement wall with windows and air vents.

Monolithic plinth on a slope

An example of installing a monolithic first floor on a slab is visible in the photo:

The characteristics of materials for such construction will depend on the characteristics of the soil and climate in a particular area. On dry, stable soils, hollow blocks with a low mass can be taken. Their main advantage is low thermal conductivity, which reduces heating costs during the construction of an operated basement level.

To get a useful room for various needs without increasing the area allotted for the construction of a private house, allows the foundation with a technical room, a cellar or a garage, laid down in the terms of the assignment at the stage of drafting the project.

If the placement of useful rooms in the basement is envisaged even before the start construction works, then you can get a tangible effect from the invested costs. But when the building has already been commissioned and is in operation, the need to maintain the stability and bearing capacity of the finished foundation imposes significant restrictions on the possible layout of the basement space and technological operations on his equipment.

Usually project documentation the height of the basement of the house was also approved, however, in an effort to reduce the cost of the foundation, the owners of the future building doubt the expediency of such a size if they are not going to operate it, that is, to arrange a basement or furnace. However, this important point for the entire object, on which not only the quality and sustainability, but also the durability of the entire building depends. Below are recommendations for the optimal solution in terms of determining the parameters.

Basement - purpose and types

The ground floor, or, as it is commonly called, the basement, is the above-ground part of the foundation, which is of great importance both in the design plan and in the operational one. The following points depend on it:

Protection of the house from interaction with soil moisture.
The stable position of buildings is more than one floor.
Compensation of the load of the entire object on the ground during shrinkage.
The possibility of placing boiler rooms and cellars with an indispensable condition for ventilation. In this case, the base height wooden house must take into account the dimensions of the equipment inside the ground floor.
Individuality in the matter of architecture.

Types of basement are different according to the architectural plan in relation to load-bearing walls and are:

Speakers. This is a classic form that provides stability to the entire building, however, such a plinth must be protected by ebbs to drain water.
Level with walls. Inexpressive in appearance, does not receive protection from moisture.
Falling, that is, the walls go beyond their edges. For ignorant people, the shape causes an opinion about the instability of the residential structure as a whole, although it is reliably protected from moisture.

Not arranging a plinth means dooming a wooden object to rapid decay and, as a result, destruction. The savings on the basis will be mythical.

Plinth dimensioning

Many factors influence the arrangement of the above-ground part of the foundation. What height of the plinth to prefer depends on the purpose and conditions for the existence of the object.

The ratio of heights to a specific level is established by the design bureau in agreement with the customer, however, the following are strictly taken into account:

The degree of deepening of the foundation.
Capriciousness of the soil and the level of occurrence of aquifers.
Climatic conditions of the area and freezing.
Installation in the basement of heating devices or other purposes.
The height of the object as a whole.
Basement ventilation.

Specific regulation minimum size such a parameter as the height of the basement, SNiP provides for at least 20 cm for monolithic slab. But based on the fact that the distribution received strip foundation, and the snow cover in central Russia is approximately 1 m, then the ground floor cannot be less than this. Plus a blind area of 0.2 m.

It becomes clear that the total height will be 1.2 m. For wooden log cabins from light timber, an increase in height is recommended.

Features of the basement and its height during construction

They are based on the prevention of capillary processes and the preservation of heat - these are important qualities for any structure, and for wood they are also life-defining, given the hostility of moisture and building material. So:

At the design stage, it is worth making all the ideas and changes to the drawings - it is quite difficult to put into practice suddenly erupted desires during the construction process. Also, do not redo the package of sketches and architectural documents on your own - arbitrariness is fraught. In the design bureau, on the contrary, specialists will take into account all the nuances, in the implementation of which the object will only benefit.

Always before the purchase of materials and the beginning of the construction of the building, its plan is created. It is especially important when designing to choose the right type of foundation, materials for its manufacture and the desired height. Next, let's take a closer look at last question and consider what the height of the foundation can be, the requirements of SNiP and why there must be a certain height for different structures.

Why is the height of the base given so much attention?

The requirements of SNiP quite clearly regulate the requirements for the base. It performs the task of supporting the entire structure and, if improperly constructed, the latter will not be able to guarantee safe conditions for people during operation. In addition, destructive factors constantly affect the foundation, and especially in its outer part: winds, rains, snow masses, the sun, etc. Therefore, it must not only protect the structure from subsidence, but also raise the material of the walls two-story house or any other structure to a safe height. Let's take a closer look:

It is great to use an elevated base as a plinth. In any case, there should be a height of walls above ground level regulated by SNiP. The advantages of using a plinth combined with a foundation are obvious - the construction of the structure will be more integral and stable.
Some SNiPs of certain materials require their remoteness from the aggressive effects of the earth: moisture, precipitation, etc. Otherwise, the lower layers of the walls may be destroyed, which can harm the entire building (especially in the case of a two-story house). As for the exact requirements, the base should be 10 cm higher than the calculated level of the maximum possible snow mass in winter. Simply put, if a lot of snow falls, then the foundation should not be exactly hidden under it. As for the strip base, the minimum height of the foundation above the ground is 30 cm.
In some cases, an elevated base is a continuation of the walls of the basement of a two-story house. By analogy with the basement, a joint construction will provide many advantages.
It is possible to create a high base as a measure to combat shrinkage, which is typical for some soils. Experienced planners always take into account all the features of the land on the site of the future building.
Elevations within 20-30 cm are characteristic for a pile foundation, as well as in cases of building a one- or two-story wooden house - the tree does not tolerate moisture.

Please note that even reliable waterproofing of the walls from the basement side will not protect them from moisture, and the only way out is to make the base with sufficient height to protect it from moisture.

Height of the strip base

It should be borne in mind that the entire height of the foundation consists of 2 parts: underground and aboveground. If you listen to the recommendations of experts, then it is optimal when it rises 40 cm from the ground. This indicator can also be influenced by the amount of precipitation and the material for laying the walls. For example, when using structural aerated concrete, much less elevation is required than in the case of cinder block.

If there are no special requirements for height requirements, then the SNiP documentation should be taken into account when determining the depth. It indicates the levels of freezing of the main types of soils and the indicators of base height recommended in each situation:

The soil is slightly heaving: freezing is 300-350 cm - the recommended foundation depth is 150 cm, 250 cm - 100 cm, 150 cm - 75 cm, 100 cm - 50 cm.
Non-porous: more than 300 cm - 100 cm, up to 300 cm - 75 cm, 200 cm - 50 cm.

Also, when determining the depth, the level of groundwater is taken into account.

Determination of the height of a monolithic base

It is worth considering some points:

The SNiP rules regulate the minimum height of such a base at 20 cm. To be more precise, this is exactly what the height of the base should be. But in regions with uneven rainfall, this indicator in the case of the construction of a two-story wooden house is increased to 40 cm - this allows you to protect the tree from moisture.
Also, in cases where the soil freezes up to 1 m, then the foundation must be installed deeper.
The advantages of a monolithic slab include its complete insensitivity to displacements of soil masses. But in the case of construction on sites with characteristic seismic activity, the width of the foundation should be increased.

General results

The smallest height of the tape base is 30 cm above ground level;
Great if the foundation performs the task of the base;
The wall material should be protected from moisture as much as possible;
It is necessary to make such a foundation so that at maximum precipitation it is 10 cm higher than the snow.

Approach the design correctly and it does not matter whether the construction of a two-story house, a bathhouse or a utility room will be carried out. A well-chosen foundation height above the ground will extend the life of the structure for a long time.

The height of the foundation for the house updated: February 26, 2018 by: zoomfund

Construction Materials

Petr Kravets

Reading time: 3 minutes

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When building a house, the height of the basement is taken arbitrarily, based on the wishes of the owner, who decided to make a room in the basement for different purposes, for example, a kitchen with a vegetable store. But in the calculation, they still use data on the type of soil, the type of foundation and the materials used.

There are cases when, when building a basement, they do not pay due attention to it, sincerely believing that it is enough just to take it beyond the surface of the earth in order to continue building the house. But this assumption is fundamentally wrong.

It must be understood that the basement is the part of the house located above the ground. And the greater the height of the basement, the less moisture penetrates inside. Groundwater, floods, precipitation - the base accounts for a lot of sources of wet exposure, and this process occurs constantly.

The foundation walls must be separated by layers of waterproofing from the main part of a two-story (or more) residential building, since moisture still penetrates through the smallest capillaries into the material, and significantly increases the level of humidity in the premises.

If a kitchen is equipped in the basement, then it is necessary to insulate from moisture from the inside, since the steam from the processing of products will form condensate.

When building a basement, you can use SNIP 2.08.01 for residential buildings and SNiP 2.08.02 for public buildings.

If the walls of the building are too low, then the bottoms of the structure will constantly get wet, which will lead to their slow destruction and loss of thermal insulation properties.

As a result, the terms of use of the building will begin to decrease, and it will not always be clear due to what factors. This explains the importance of occupying the plinth of the required height from the surface of the earth.

Typical parameters for the height of the basement from the ground according to the rules

To find out what the maximum height of the technical underground can be, it is necessary to clarify the minimum parameters. According to requirements building codes, in a residential country house, the minimum height of the basement should be approximately 0.3-0.4 m.

When installing with a wooden beam, this distance should be increased to 0.6-0.8 m. If a zero floor is provided, then the minimum height of the technical underground will be from 1.5-2 m.

To determine the height in a particular case, the climatic conditions of the construction site, the likelihood of flooding with melt and groundwater, the frequency and abundance of precipitation, indoor and outdoor temperatures (especially in winter) are taken into account.

If it is possible to take into account all these factors, it is better to seek the help of professionals, although theoretically, these calculations can be carried out independently.

This issue touches upon the moments of occurrence of risks of repair and re-equipment of the structure, as well as significant financial expenses.

In order to have an understanding of why the optimal height of the basement of a house is calculated, it is necessary to determine several of its functions:

Preventing wetting of the interior of the house;
Compensation for shrinkage phenomena of the soil that occur when the weight of the house structure is pressed on it;
Protection of facing materials of the building from pollution;
High-quality underground ventilation (during the arrangement of kitchens, additional ventilation ducts are made);
Increasing the service life of the floor when using tape or column foundation, in addition, the thermal insulation indicators of the subfloor depend on the height of the base;
Improvement appearance buildings, since a house with a basement visually looks very presentable.

It is necessary to pay special attention to the height of the plinth when building from a wooden beam, which is prone to decay at the ends of the logs, which greatly complicates the repair and restoration work.

With this type of construction, they try to reduce the likelihood of wood rotting, for this, the height of the basement above the ground is increased. Practice shows that some builders make a huge mistake, trying to reduce this height and neglecting the plinth for the sake of aesthetic considerations.

Of the disadvantages of increasing the height of the basement, one can only mention the rise in the cost of building a residential building.

Important! In order to focus not on the advice of builders and your own considerations, it is important to know regulations, where the verified minimum height is indicated with a decoding of the origin of these verified values.

For example, SNIPs 31-02-2001 and 2.08.01-89 (ground floor height) set a height of at least 0.2 m for columnar and pile foundations. Such a retreat is necessary for heaving soils to prevent their impact on the house. The greater the slope of the earth, the higher the ground floor should be.

Types of plinths

The construction of the basement may differ in the type and sequence of work, depending on the type of foundation. Most often used tape or pile foundations. In some cases, the base of the house is poured with a monolithic layer.

When choosing a strip type of foundation, the basement can be monolithic (in the form of a concrete wall) or masonry (in this embodiment, the foundation is made to the level of the ground, and then masonry is erected - it is not enough to protect against various influences, therefore it is necessary to carry out insulation work and decorative finishing).

With respect to the walls of the facade, the plinth can be designed as a sinking (for buildings with thick walls), protruding (the only possible for buildings where the basement and thin walls ( apartment buildings)), and flush (part of the base smoothly into the facade, all parts of the house are located in the same plane, usually one-story houses or a summer kitchen in the country).

The influence of the type of basement on its height from the ground according to the norms

The most expensive, but necessary option, is the protruding view. It is only possible for buildings with a used basement. The height is taken for such a case as maximum, otherwise it is impossible to achieve acceptable thermal insulation characteristics of the building.

For buildings without basements and basement (most often it is a summer kitchen on personal plot) you should choose the sinking option. Facade overhanging wall will be the optimal protection against mechanical and atmospheric damage. In this case, the height is taken to be minimal, the lower it is, the better the protection will be.

The basement of a house on one of the low foundations is usually made of blocks or bricks. It should be noted that the use of blocks significantly increases the characteristics of the building in terms of strength and stability.

Both types of performance require finishing works and carrying out insulation work. If ground water pass close to the surface, then equip drainage system, and if it is deep enough, it is enough to make a blind area.

The foundation on piles can be low (if the grillage is located at the ground level), or elevated. Columnar, as the most unstable, requires a height of at least 0.2 m.

The gaps between the pillars are laid with bricks or shields. Because of design features there can be no excessively high base. Location on piles with different height options can be found in the photo in the public domain.

Features of waterproofing and insulation at different heights

But no matter how thoroughly the strip foundation is erected, its effectiveness can be reduced to zero if ventilation holes are not equipped around the entire perimeter at a distance of no more than 3 meters from each other. They provide high-quality ventilation, as well as internal partitions and walls.

Close such openings with ventilation grilles to protect against the ingress of debris, dirt and small insects into the room. It is strictly forbidden to use plugs for this purpose, since the moisture inherent in basements can lead to mold and fungal manifestations.

If a kitchen is being built in the basement, then steam from processed products should also be taken into account. Examples of this use of undergrounds can be found in many photos in open sources.

Important! In a public building, technical cellars should be separated in order to fire safety, partitions into compartments no more than 500 m2, in non-sectional residential buildings, and in sectional - in sections.