The height of the base from the ground according to the norms. The optimal height of the basement of the house above the ground. The influence of the type of basement on its height from the ground according to the norms

How high should the basement of the house be and what does this indicator affect? How to determine the optimal height of the plinth for a wooden house?

Many owners, when building a house with their own hands, doubt whether it is worth paying attention to the height of the basement. Some even believe that it is enough to simply raise the base to ground level, after which walls can be erected.

In reality, this is not enough. It should be understood that, to prevent the occurrence of capillary processes in them. The fact is that the humidity of the lower part of the house and the upper one can vary significantly due to the proximity of groundwater, snow melt and many other factors.

As a result, low-lying walls made of wood or porous materials will get wet, which will not only worsen their thermal insulation qualities, but also reduce the life of the entire structure. The high base of the house will just prevent this process.

standard height

The optimal height of the basement of a residential building is 35-40 cm. For wooden buildings, it is better to make it higher - 50 - 90 cm. For buildings with basement floors, this value can reach two meters.

When determining the height, it is necessary to take into account climatic conditions, such as the average temperature level during the heating season, the amount of snow, etc.

Main functions

Now let's look at all the functions that the above-ground part of the base of the house performs in order to understand what role its height plays:

Note!
The height of the plinth of a wooden house is especially important, since rotting of the lower crown is an eternal problem for houses made of logs and timber.
Therefore, it is necessary to build a foundation from damp-resistant materials.

The only drawback of a high base is that the cost of construction increases. Therefore, many developers, for reasons of economy, are trying to reduce it. However, such savings are not justified.

Types of plinths

Depending on the type of foundation, the methods of erecting the basement may vary.

Consider its device on two types of base:

• Tape;
• Svain.

On the tape

In the first case, the following types of base are usually made:

• Monolithic - the aboveground and underground part of the foundation is a monolithic concrete wall. It is erected simultaneously with the pouring of the foundation.
• In the form of masonry - in this case, the foundation is raised to the level of the soil, after which masonry is made of brick or other material. This design is less protected than a monolithic wall, therefore, it needs additional finishing.

On a pile

As a rule, the greatest difficulty in construction is the construction of a basement on a pile foundation. Its height is determined by the above-ground part of the piles.

According to the type of device, such a base is of two types:

• Hinged structure;
• On a strip shallow foundation.

The easiest and cheapest way is to make the foundation of the first type. It is based on a crate, which is attached to piles around the perimeter of the building. It can be made from wooden beams or metal elements. Further, the crate is sheathed with facing material, for example,.

Note!
The height of the column foundation must be at least 20 cm to prevent possible impact heaving soil for construction.

The second type of foundation is more difficult to manufacture and costly. Its principle is to arrange a strip foundation around the perimeter of the room, on top of which masonry is performed. The advantages of this design include the fact that it insulates the structure much better.

In the photo - a plinth sheathed with siding

Finishing the above-ground part of the base

Despite the fact that the high plinth itself performs a protective function, in order to make the structure more durable, it is necessary to finish it. This will prevent the negative impact of precipitation and, moreover, will make the building more beautiful. As an example, consider plinth siding, as the most popular material.

Brief installation instructions are as follows:

• Work begins with the preparation of the walls - it is necessary to eliminate irregularities. If the geometry of the walls is severely disturbed, then it is more expedient to perform a crate than to align them.
• Then the starting strip is mounted, which is installed strictly horizontally, at a height of 40 mm above the lower point of the future lining.
• Then the panel is installed in the guide bar and fixed with self-tapping screws.
• Next, the second panel is inserted and shifted to the previous one. At the joints, it is necessary to leave a small gap, which will allow the material to expand freely with temperature changes.
• Further, the entire remaining area is sheathed in the same way.
• At the end of the work on the panels, the finishing bar is installed.

Advice!
To insulate the building, heat-insulating material can be laid under the cladding.

Now the lower part of the house is not afraid of any precipitation and other atmospheric phenomena.

Conclusion

From all of the above, it follows that the higher the base, the less problems there will be in the future with heat leakage and the safety of the walls of the house. However, the height must be reasonable, as it increases the cost of the building. At the same time, it is necessary to take care of protecting the base itself by finishing it with reliable material.

For more information on this topic, see the video in this article.

The parameters determined during the design of building structures include 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.

Base footprint in more 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.

The limit on the lower mark can serve as high level ground water. 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. The useful use of the internal volume of the foundation structure significantly increases the scale of earthworks, since it is necessary to select all the soil in the pit and go deep to the hard 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.

The project, based on engineering and geological surveys, includes the possibility of how the building can give subsequent shrinkage.

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

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 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 floor cracks.

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, as a rule, 0.5 m is sufficient.

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

In a monolithic MZLF, ventilation is provided for ventilation, which have established standard dimensions, and this also affects the height of the aerial 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 estimate, it is assumed that the cost of the foundation is about 30% of the total estimate 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.

The design calculation of a screw foundation for buildings that are light frames, log cabins, prefabricated panels 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, a standard of 10 cm of excess snow cover is used, which is typical for a given climatic region.

How to determine in practice with the help of a 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 of no more than permissible values.

At the design stage, in accordance with the type of building, individual parameters of the foundation are selected: the area of ​​\u200b\u200bthe sole, on which the width of the foundation and the height of the foundation above the ground depend.

The optimal height of the basement elevated above the ground is 30–40 cm. If the house has an underground floor, then the height can reach 1.5–2 m.

To determine the height of the base, you need to pay attention to atmospheric phenomena on the ground:

• Indoor and outdoor temperature in winter;
• Snow level;
• Abundance of precipitation;
• The likelihood of flooding;
• Ground water level.

The above-ground part of the foundation, the most destroyed under the influence of atmospheric phenomena.

What is this part of the foundation for? Let's consider in more detail:

For all these indicators, we can conclude that the optimal height above ground level is 350-400 mm. If the foundation is located high above the ground, this is good in all respects. You also need to take into account the heat and waterproofing of the lower part of the foundation. After all, these indicators will not only save your foundation, but also reduce heat loss.

Balancing between necessity and redundancy

The customer makes the main contribution of money in building the foundation. If you choose a special area and take into account all the nuances, then the foundation will be a durable platform for the whole house.

The height of the pile foundation above the ground is used together with the foot area and their width. And it depends on the type of building construction.

Finishing the above-ground part with metal siding

The basement cladding with metal siding has become the most popular.

Siding principle:

Foundation types. Relation to ground level

The dependence of the height of the foundation above the ground:

From all these points, we can conclude that, subject to all conditions, it is important to determine the height of the foundation.

There are 4 types of foundation:

• Tape
• Columnar
• Monolithic
• pile

Strip foundation - This is a reinforced concrete strip over the entire area of ​​\u200b\u200bthe building. It is used in the construction of private houses. Thanks to a simple design, you can make a warm underground. The strip foundation is used in the construction of heavy walls. The optimal height is 2 m.

Column Foundation used in light structures of one-story houses. Used only on immovable ground. Cannot be used on loose soils. Easy to make, can be used on slopes. Service life 50 years. With this type of foundation, it is impossible to create a basement. The columnar foundation can be built of brick, asbestos pipes, tree. The height of the pillar is 1.5 m.

Monolithic foundation is a reinforced foundation. Easy to build, does not require special equipment. A large area distributes the load on the ground. The monolithic foundation is reliable and has a long service life. This foundation is made of reinforced concrete and has a height of 300 mm. A monolithic foundation is built on all types of soil. The indicator for this type of foundation is 1.2 m.

pile foundation used in all kinds of constructions. It has low cost, high bearing capacity. It is used on all types of soils, except stony. With an uneven structure, its shrinkage is possible. Its service life is 100 years. The height of the pile foundation is 2–2.2 m.

Do-it-yourself arched canopy

The arched canopy is an indispensable extension on the territory of the dacha, country house or cottage. The most commonly used material is polycarbonate. It is lightweight, durable, fireproof, much stronger than plastic.

First of all, you need to concrete the base for the racks, then the arches are installed on the posts. The structure is fixed simultaneously from opposite sides, so that there are no distortions. We connect farms and racks, and connect arches with guides. Holes are drilled on polycarbonate at a distance of no more than 30 cm and rubber gaskets are fixed. Connect the frame and polycarbonate. Go through the joints with sealant when the canopy has already been attached.

The optimal height of the foundation for a wooden house

The optimal height of the foundation for a wooden house depends on a number of factors:

• From the climatic conditions of the area. The level of permafrost and water layers.
• from geological conditions.
• From the selected type.
• From load. Seasonal or year-round operation.

Rounded log or glued laminated timber. What's better?

The disadvantage of the rounded log is its shrinkage after the construction period. Over time, such houses can squint. Glued laminated timber retains its shape for many years and the house does not lose its external and internal beauty. The strength of glued laminated timber depends on its manufacturing technology.

The rounded log is made of solid wood, by mechanical processing, rounded. Glued laminated timber is made from high quality boards. Coniferous trees are used for its manufacture. The boards are impregnated with a special solution and trimmed. After all this, the boards are glued together so that the wood fibers match. Therefore, glued laminated timber is better for the house.

Individual heating of the house from rounded logs.

The most common method of heating in a rounded house is a gas boiler. Fuel is much cheaper, High efficiency.

Also as heating choose:

1. Electric wall or floor boilers.
2. Coal or wood stoves.
3. Wood burning, electric fireplaces

Repair of a house from rounded logs: disadvantages

• It should take 6 months from the start of construction to its finishing work. High percentage of wood shrinkage 10-12%. If you do not wait for the completion of the active phase, then you will get through cracks in the walls and a skewed frame.
• After 2 years, the procedure for the second caulking of seams is repeated.
• Wooden walls need preventive maintenance and repair.

You can build your own house, but we recommend that you turn to quality specialists who will perform any type of work. With us you save up to 500 000 rubles.

Before erecting any building, every serious builder will draw up a competent and detailed design of the structure, including the foundation. The project should indicate all the necessary parameters of the base: the width of the foundation itself (this applies, first of all, to the strip base), the area of ​​\u200b\u200bits sole, the depth, the material used in the construction and the height of the foundation above the ground. All this must be taken into account at the design stage.

But knowledge cannot be used without understanding its essence, even if it is confirmed by the word of experienced builders. And in order to do any business correctly, it is necessary to understand the reasons for precisely such parameters and requirements. Here we are going to deal with the last parameter of the base of the house indicated in the enumeration. What should be the height of the foundation and why is it necessary to know? Why do recommendations and projects indicate certain figures? What experience do builders rely on?

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Difficult choice of ideal

It is believed that the price of the foundation in the total estimate for the construction of a house is about 30%. Therefore, if there is an opportunity to save money, then most will definitely do it. And in the parameters of the foundation there is an obvious point at which costs can be well reduced - this is its height above the ground. The fact is that if the depth depends on objective and obvious reasons for everyone, changing something there, in terms of economy, is fraught, then the distance from the ground to the wall simply attracts the thrifty. After all, in fact, what is above the ground is the above-ground part of the building, and there is a temptation to make it all from cheaper materials. After all, each cm of the foundation in terms of cost is much more expensive than the same cm of walls, especially if the latter are made of cheap materials (wooden, panel, etc. buildings).

But such savings are a mistake, and it is better for the owner of the future house to carefully read the requirements for this part of the foundation and understand why they are needed in order to take a balanced approach to the issue of the height of a strip or other foundation.

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The height of the base above the ground, what is its role?

Having carefully studied the role of the foundation of the house, you can see that it experiences various adverse factors. This is especially noticeable at the boundary between the soil and the atmosphere. This shows that the parameters of a conventional strip, block and other foundation include not only such functions as providing reliable support for the entire structure, isolating the house from harmful factors from the ground (primarily moisture), but also the function of raising walls and residential level in general over all negative weather manifestations. Let's take a look at what we mean point by point.

1. A highly erected foundation in its upper part can be well used as the base of a building. The win here is obvious, the whole structure will have best performance than when the foundation and plinth are clearly separated. This will affect both the performance of the house and its integrity.
2. A high strip or block foundation has the best characteristics for protecting the walls of the house from moisture. Even if you use protection for the lower part of the walls (waterproofing, blind area, etc.), it will still be constantly moistened under the influence of ground moisture or precipitation. A high base in this case will protect the house much more reliably from moisture. The upper boundary of the foundation should rise 10 centimeters above the level of snow that falls in the snowiest winters. But in any case, the upper limit of the strip base should be no less than 30 cm above ground level.
3. The base elevated above ground level is sometimes part of the basements under the house, being a reflection of the design characteristics of the building. As in the case of the basement, such a house design will have a good effect on its operation.
4. An elevation of 20-30 cm is also characteristic of the pile and columnar base. There, this measure was taken as part of the fight against unstable soils. Heaving soils with this design have less impact on the structure during seasonal movements. In some cases, due to the slope of the terrain, this height above ground level can be much greater.
5. Very often it is a measure to combat the shrinkage of the structure. That is, taking into account the characteristics of the soil, builders pre-throw some additional height of the base, based on the future subsidence of the house.
6. During construction, materials are often used that are extremely unstable to high humidity and other environmental influences, such as wood. In this case, builders can also use a high base to keep the wood from coming into contact with wet ground.

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Calculation of the height of the strip foundation

Consider the calculation of the parameters of its height for an average house. The practice of the modern building industry shows that the height of the above-ground part of the base of the house should be related to its width as one to four. We are talking about a classic shallow-depth monolithic strip foundation, without basements and basement, with filling the inter-foundation space with soil. That is, the height of the part of the foundation above the ground should be 4 times the width. In this case, the above-ground part cannot be larger than the underground, and the opposite situation will be quite common. In our area, both parts of the foundation, as a rule, have the same height and depth characteristics and are about 45-50 cm. If the house has an underground, then there must be air vents in the foundation for proper ventilation of underground spaces.