It is known that a concrete foundation of any type must necessarily rise some distance above the soil level. Thanks to this, it is possible to isolate the walls of the building from its foundation. This prevents the harmful effects of capillary processes that constantly replenish the building with soil moisture.
The foundation is in conditions of high humidity almost constantly. This is facilitated by precipitation, groundwater, and melting snow masses. Therefore, there must be some minimum height of the foundation above the ground to ensure the safety and dryness of the walls.
What functions does the foundation of a building perform?
The foundation, raised above the soil level, not only serves as a support for the entire structure.
In addition to this main function, it also solves certain problems:
Foundation height of a wooden house
For a wooden house, a sufficient height of the base is especially important, since preventing the bottom row of wood from rotting is an indispensable condition for constructing a house made of wood. Such a foundation can be made of concrete, brick, 
metal or wood. The type of foundation can be strip, pile or columnar.
An indispensable condition is high-quality waterproofing of the base. As mandatory waterproofing, you can use coating materials (bitumen mastic, cement-polymer based hydraulic mixture), as well as rolled materials (waterproofing, glass insulation, roofing felt).
The optimal height of the base is selected based on the climatic characteristics of the area. It usually exceeds the average snow depth by 10 cm. It is advisable to protect the foundation for a wooden house from dampness not only from below, but also from the sides. This can be done by covering it with ceramic tiles or clinker.
The higher the base of the house, the better its thermal insulation will be, and the longer it will last without complaints.
Height of strip foundation
consists of its aboveground and underground parts. The optimal height of a monolithic strip foundation above the ground is about 35-40 cm. In some cases, this value may change. But its underground depth depends on the properties of the soil.According to the provisions of SNiP, the foundation depth is determined as follows:
- Freezing of non-heaving soil by 2 m or slightly heaving soil by 1 m - the foundation is buried 50 cm.
- Freezing of non-heaving soil by 3 m or slightly heaving soil by 1.5 m - the foundation is deepened to 75 cm.
- Freezing of non-heaving soil more than 3 m or slightly heaving soil by 2.5 m - the foundation is buried 100 cm.
- Freezing of slightly heaving soil by 3-3.5 m - the foundation is deepened to 150 cm.
The depth of the strip foundation very much depends on the groundwater level. When groundwater is located close to the surface, it is strictly not recommended to lay weakly buried foundations.
Regardless of the level of soil freezing and soil characteristics. Groundwater contributes not only to dampening of the foundation, but also to its sedimentation, distortion and gradual destruction.
How to calculate the height of a slab foundation?
Slab foundations are usually preferred to be erected on weak, unstable, 
heaving soils. A monolithic slab is able to withstand soil heaving and settlement without compromising the integrity of the entire structure. But this does not mean that it can be laid directly on the ground, that is, a non-buried foundation can be made. In some cases this is allowed, but only on rocky and non-heaving soils. In all other cases, the reinforced concrete slab must be buried to a certain level.
Before erecting any building, every serious builder will draw up a competent and detailed design of the structure, including the foundation. The project must indicate all the necessary parameters of the foundation: the width of the foundation itself (this applies, first of all, to the strip foundation), the area of its base, the depth, the material used during 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 confirmed by the word of experienced builders. And in order to do any task 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 house foundation listed in the listing. What should be the height of the foundation and why is it necessary to know this? Why are certain numbers indicated in recommendations and projects? 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 where costs can be greatly reduced - this is its height above the ground. The fact is that if the depth depends on objective and obvious reasons to 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, every cm of 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 home 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 unfavorable factors. This is especially noticeable at the boundary between the soil and the atmosphere. From this it can be seen that the parameters of a conventional strip, block and other foundation include not only such functions as providing reliable support for the entire structure, insulating the house from harmful factors from the soil (primarily moisture), but also the function of raising walls and the residential level in general over all negative weather manifestations. Let's look at what this means point by point.
- A highly erected foundation in its upper part can be well used as the base of a building. The benefit here is obvious; a solid structure will have better characteristics than in the case where the foundation and base are clearly separated. This will affect both the performance of the house and its integrity.
- A high strip or block foundation has the best characteristics for protecting the walls of a 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 from moisture much more reliably. 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.
- The base, elevated above ground level, is sometimes part of the basements under the house, reflecting the design characteristics of the building. As in the case of the base, such a design of the house will have a good effect on its operation.
- An elevation of 20-30 cm is also typical for pile and columnar foundations. 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.
- Very often it is a measure to combat the shrinkage of a structure. That is, taking into account the characteristics of the soil, builders add some additional height to the foundation in advance in anticipation of future subsidence of the house.
- During construction, materials that are extremely unstable to high humidity and other environmental influences, such as wood, are often used. In this case, builders can also use a high base to prevent the wood from coming into contact with wet soil.
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Calculation of the height of the strip foundation
Let's look at calculating the parameters of its height for an average house. The practice of the modern construction industry shows that the height of the above-ground part of the base of a house should be related to its width as one to four. We are talking about a classic shallow monolithic strip foundation, without basements and a plinth, with the inter-foundation space filled 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 normal. 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 floor, then the foundation must have vents for proper ventilation of the underground spaces.
The construction of concrete foundations in Moscow, the region and throughout the country begins with a detailed and technically correct calculation of all the nuances and features. To establish the main characteristics of the foundation of the cottage, the design of the cottage, the features of the relief and soil conditions must be taken into account, and the meteorological situation in each specific region is also taken into account. All these subtleties are needed to calculate the height of the foundation in its above-ground part - that structural element on which many try to save money.
InnovaStroy specialists, based on the requirements of GOST and SNiP, create such structural elements that, on the one hand, will save the developer money, and on the other, will ensure the safety of the building, its load-bearing structures and finishing, no matter what materials they are made of.
The height of the foundation above the ground - what is it?
As you know, the foundation of any cottage is buried into the ground to a certain distance, depending on the design features of the building, design loads, characteristics of the soil base and the location of groundwater. Naturally, the underground part of the foundation can be of very different depths, up to 1.2 meters with no space involved. With the creation of a basement or equipped basement, this depth can reach 3 meters. The question naturally arises about that part of the base that protrudes above ground level - that is, above the zero height mark. Many believe that this part can be neglected and save significant money on more than one cubic meter of monolith or brick.
In fact, those few tens of centimeters separating the surface of the earth from the beginning of the load-bearing walls are designed to provide increased protection of the entire structure from adverse external influences. The height of the foundation above the zero level is determined at the design stage by our architects and designers. This part of the building’s foundation is treated in the same way as all other elements - waterproofing, insulation, decorative external cladding. But in addition to aesthetic beauty, the basement distance also carries a functional load, which we do not recommend discounting if you want your country mansion to last for a very long time and not require repairs.
The height of the foundation of the house: why is it needed?
The distance from the ground to the lower edge of load-bearing walls and external decoration is designed to provide several protective functions at once, for which it is actually created by architects and designers. Below we will describe the main functions of the basement, without taking into account the option with a full basement, since in this case, according to GOST, more than 1 meter of distance from the ground to the first floor is required. So, the main functions of the above-ground part of the foundation:
- Leveling the terrain of the site without making changes to the topography of the territory, with the absence of large volumes of earthworks. For very large differences in site elevation, it is best to order a pile foundation in InnovaStroy to minimize any excavation operations;
- Resistance to heaving of the soil layer during the freezing process - thus, the soil acts only in the horizontal direction on the base walls, and does not apply force to the load-bearing structures of the walls of the cottage;
- Protection against waterlogging during critical amounts of precipitation. Since the above-ground part of the foundation is slightly recessed in relation to the plane of the wall, it is easier to drain rainwater and condensate from the walls, which helps prevent the appearance of dampness and mold;
- A certain height of the foundation above the ground allows you to minimize the impact of capillary moisture and evaporation. During the process of atmospheric exposure, microscopic pockets of moisture appear in the surrounding space and territory - dew, for example - they evaporate and can have a detrimental effect on the house, settling on surfaces. The distance from the zero construction mark allows this type of moisture to be removed into the drainage system even before it settles on the walls themselves;
- The height of the house's foundation ensures that there are vents in the base to improve ventilation of the subfloor space. Another functional load is working as an additional waterproofing barrier, together with the blind area;
- Let's not forget about the aesthetic beauty of the building, which has a small distance between the ground and the walls, usually finished in contrasting materials in relation to the external façade of the walls.
How high should the foundation be above ground level?
This issue is very relevant, since most protective processes are not visible during operation, and all the benefits appear only in the long term. Based on this, many developers are trying to save on this design and exclude it from construction and estimate documentation.
However, many generations of builders and architects have repeatedly tested different options for constructing a country cottage, which has led, as a result, to the widespread use of above-ground basement distances in the construction of all houses. For each type of building material from which the cottage will be built, there are certain requirements about how high the foundation should be above ground level, which is necessarily taken into account by the designers.
The most common parameter is in the range from 30 to 50 centimeters - which optimally provides protection for a house built in central Russia. If the maximum level of snowfall reaches 20 centimeters, then the distance can be increased.
It is also worth considering the fact that about 10 centimeters of this height will be occupied by a blind area with surface finishing material - so you will have to increase the distance to the ground. Naturally, there are cases when 20 centimeters of height of the above-ground part of the foundation is enough - this is in those areas where the soils are not heaving and the maximum snowfall does not exceed 5 centimeters - in the south of our country.
We cannot ignore the fact that when constructing a country house, the height between the ground and the base of the walls is used to give the building originality and a unique style - for example, terraces are built below floor level with wide steps, or the platform can be built on stilts, which will give the house has charm and slight sophistication. The entrance block also has several steps with railings and a veranda, which also affects the image of your country residence. Perhaps the height of the above-ground part of the foundation is that rare case in architecture when purely functional details of a house could be turned into its highlight and an unusual decorative element. There are even cases when the base part is made protruding, in the form of an ancient “heap” - there are no restrictions on design and engineering ideas, as long as this part of the foundation regularly performs its main functions of protecting the house.
What is the optimal height of the foundation above the ground for the types of structures?
Based on the base material from which the supporting structure of the building will be created, the parameters of the distance from the zero mark are also selected. For example, the height of a shallow strip foundation is almost always equal to its underground part - that is, about 50-60 centimeters. However, there is no particular difference where strip foundation in the Moscow region will fit, since the approximate profile of the soil layer is the same for the entire central region and most surrounding areas of the country. By type of construction, you can provide approximate indicators for the distance from the edge of the wall to the zero ground level:
- 30-40 centimeters – for brick and monolithic structures;
- 40-50 centimeters – when using gas-foam blocks, large-sized ceramic materials;
- Over 50 centimeters - when constructing a frame, prefabricated or wooden house, since the material is most susceptible to external influences.
How high should a monolithic foundation be made?
This question arises most often, since the strip foundation has a fairly small surface area of the foundation, which can be increased using various building materials. In the pile and screw version of the foundation, the technology itself provides for a minimum of 20 centimeters from the extreme point of the ground to the bottom of the grillage frame. Since a monolithic foundation slab, the price of which is already quite high, requires uniform filling to a certain height, it is best to consult with the specialists of our company on how to simplify the design of the base and reduce the financial costs of creating a slab foundation. It is quite possible that the building design will allow you to create contour building of the base part using bricks, and filling the interior space with a more accessible floor screed. In any case, professional help will never hurt when creating a reliable and durable foundation.
Only a trained InnovaStroy specialist can determine exactly what foundation height will be sufficient for your particular cottage. More than 7 years of practice and our own experience in the field of suburban construction make it possible to provide each customer with objective and substantiated data on all the nuances of building a foundation for a cottage not only in Moscow, but throughout Russia. Use the services of professionals to prevent premature and unexpected costs for repairs and restoration of load-bearing parts of the cottage.
Always before purchasing materials and starting construction of a building, a plan is created. When designing, it is especially important to choose the right type of foundation, materials for its manufacture and the desired height. Next, we will dwell on the last question in more detail and consider what the height of the foundation can be, the requirements of SNiP and why there should 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 foundation. It performs the task of supporting the entire structure, and if constructed incorrectly, the latter will not be able to guarantee safe conditions for people during operation. In addition, the foundation is constantly affected by destructive factors, 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 of a two-story house or any other structure by safe height. Let's take a closer look:
- It’s great to use a raised base as a plinth. In any case, there must be an elevation of the walls above ground level regulated by SNiP. The advantages of using a plinth combined with a foundation are obvious - the structure of the structure will be more holistic and stable.
- Some SNiP of certain materials require their distance from the aggressive influence 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 hidden under it. As for the strip base, the minimum height of the foundation above the ground is 30 cm.
- In some cases, the elevated base is a continuation of the basement walls of a two-story house. Similar to the plinth analogy, 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 at the site where the future building will be located.
- Elevations within the range of 20-30 cm are typical for a pile foundation, as well as in cases of constructing a one- or two-story wooden house - the tree does not tolerate exposure to moisture.
Please note that even reliable waterproofing of the walls on the base side will not protect them from moisture and the only way out is to make the base with a sufficient height to protect it from moisture.
Height of strip base
It must be taken into account 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, a significantly lower elevation is required than in the case of cinder block.
If there are no special requirements for height requirements, then SNiP documentation should be taken into account when determining the depth. It indicates the freezing levels of the main types of soil and the recommended base heights in each situation:
- The soil is slightly heaving: freezing is 300-350 cm - recommended foundation depth is 150 cm, 250 cm - 100 cm, 150 cm - 75 cm, 100 cm - 50 cm.
- Non-heaving: more than 300 cm - 100 cm, up to 300 cm - 75 cm, 200 cm - 50 cm.
Also, when determining the depth, the groundwater level is taken into account.
Determining the height of a monolithic base
It is worth considering some points:
- 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 figure in the case of building 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 to 1 m, the base should be installed deeper.
- The advantages of a monolithic slab include its complete insusceptibility to displacements of soil masses. But in the case of construction in areas with characteristic seismic activity, the width of the foundation should be increased.
General results
- The minimum height of the strip base is 30 cm above ground level;
- It’s great if the foundation performs the task of the base;
- The wall material should be protected as much as possible from moisture;
- It is necessary to make such a foundation 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, bathhouse or 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.
House foundation height updated: February 26, 2018 by: zoomfund
The height of the base of a country house above the ground can be very different. It is influenced by several factors, ranging from the type of foundation to the depth of groundwater. Many homeowners who are engaged in construction on their own do not pay due attention to the issue of the height of the basement of the building, because they are sure that it is enough to make the basement slightly raised above the ground in order to continue construction work.
However, this is not enough. You need to understand that the basement is the above-ground part of the foundation of the house. The higher it is from the surface, the more difficult it is for moisture from the ground to penetrate into living spaces. The walls of the basement must be separated from the walls of the first floor by a waterproofing layer. This is done so that moisture that could penetrate into the base material does not penetrate through the capillaries into the wall material. The level of humidity in different parts of the house can vary significantly, and this must be taken into account during construction.
If the walls of a building are located too low, the structure and main building materials will constantly get wet, their thermal insulation properties will deteriorate, and internal destructive processes will begin to occur. Gradually, these processes lead to the complete destruction of the building material from the inside. As a result, the service life of the structure is significantly reduced, and the owners sometimes cannot determine why this is happening. And the answer is simple - insufficient height of the base above the ground.
Standard height
In an ordinary country house, the base should rise above the ground by about 30-40 cm. If the building is built of wood, then it is better to take a higher height (about 60-80 cm). If a country house has an underground floor, then the height indicators can reach 1.5-2 meters.
When determining the height of the base, it is necessary to take into account the weather conditions of the area: indoor and outdoor temperatures in winter, snow level, abundance of precipitation, probability of flooding, groundwater level. It is quite difficult for a non-professional to take into account all these factors. Therefore, even if you are building a house yourself, it is best to turn to specialists for the correct calculations. One-time minor costs at this stage will help to avoid serious financial losses in the future for repairs and re-equipment of the structure.
Typical dimensions and design of a monolithic strip base.
To clearly understand the meaning of a certain plinth height, it is necessary to consider several main functions performed by this part of the building:
- The base prevents the internal structures of the house from getting wet.
- With the help of a plinth, the finishing materials of the building (for example, plastic panels) are protected from contamination.
- Compensation occurs for soil shrinkage observed due to the impact of the weight of the house structure.
- If a strip or column foundation was used to build the house, then the distance from the ground to the floor will affect the lifespan of the floor, which is often made of wood. In addition, the thermal insulation characteristics of the subfloor will depend on this indicator.
- The plinth helps to properly ventilate the subfloor.
- Among other things, the plinth is an architectural solution that influences the overall visual impression of the building.
Experts recommend paying special attention to the height of the base in wooden buildings, because when the lower crowns rot, it becomes very difficult to carry out any repair work. That is why developers are striving to reduce the likelihood of wood rotting by increasing the height of the base. But during self-construction, owners often, on the contrary, reduce the height of the basement, trying to make the exterior of the house more aesthetically pleasing. Thus they are making a serious mistake.
The main disadvantage of a high base is that as it increases, the cost of construction work will increase.
Types of socles
Methods for constructing a plinth will vary depending on the type of foundation of the building. In our country, either a strip or pile foundation is most often used. Monolithic foundations are also very popular.
The base is made of brickwork.
If a strip foundation was erected, then the base can be made in two solutions:
- Monolithic. In this case, the foundation is made in the form of a concrete wall. Such a base must be built together with the pouring of the foundation.
- Masonry. When making a masonry plinth, the foundation is made up to the ground level, then brick (or other building material) masonry is made. Such a design cannot boast a high level of protection from various influences (when compared with a monolithic alternative), so additional cladding and finishing are necessary.
Using a pile foundation above ground comes with some challenges. The height and thickness of the base in this case are determined depending on the ground part of the piles. The base for a pile foundation can be suspended or made on a strip foundation.
Finishing the house with siding.
The finishing principles in this case are as follows:
- Finishing work should begin with surface preparation. It is not necessary, but it is highly advisable to remove all defects of the rough wall. If the walls have significant unevenness, then it is recommended to make high-quality sheathing rather than waste extra time on leveling.
- After this, a starting rail is installed, which is mounted in a horizontal position (approximately at a height of 40-45 mm above the lowest point).
- Next, the siding sheet is mounted into the guide rail and secured using self-tapping screws or special fixing elements.
- Then you need to insert a second sheet of siding, sliding it towards the previous one. It is recommended to leave a minimum gap at the joints so that the material can expand without problems when heated. The minimum temperature, by the way, will slightly reduce the thickness of the finishing elements.
- Subsequently, it is necessary in the same way.
Naturally, the basement of the building can be finished with any other modern or traditional facing materials. The main thing in this case is to ensure the protection of construction materials from moisture and cold air. In addition, attention must be paid to the construction of the blind area and drainage system on the site. With their help, it will be possible to prevent flooding of the underground premises of the house, as well as the effect of moisture on structures.
What does altitude affect?
From everything that was said above, we can conclude that the security of the interior of a country house and the building materials used for its construction will depend on the height of the base. At the same time, the height must be determined wisely and with calculation, because with every centimeter of the above-ground part the cost of construction work will increase. In addition, special attention should be paid to protecting the basement of the building from the cold by placing a high-quality thermal insulation layer in the space between the wall and the finishing materials.
The higher the base, the better, if the material for building a house is exposed to biological influences and moisture. We are, of course, talking about wood. When building wooden houses, it is best to make the most reliable base with effective waterproofing and thermal insulation layers.
If you are having difficulty calculating the height of the basement of your country house, then you should seek help from specialists. Of course, this type of help is not free, however, it is better to incur costs at this stage of construction than to spend money on home repairs in the future.