Before building a house with your own hands, you must definitely choose the right foundation. When choosing, you will have to focus on a large number of factors. The question is very responsible, since when moving to the construction of the walls of the house, the supporting part of the building will become inaccessible for repair or correction of errors. To understand what kind of foundation is needed for a house of foam blocks, you will need to understand the characteristics of the material, to understand how the calculation is performed.
Key selection criteria
To understand which foundation is best for a house of foam blocks, you will need to pay attention to the features of the wall material. Do-it-yourself construction of such wall fences, if we consider the effect on the supporting part of the building, has such features:
- Instability to uneven shrinkage of the soil under the sole and, accordingly, the foundation. Foam house - a structure made of piece materials. The device of such a wall does not provide strong vertical bonds between the elements, therefore, does not prevent their displacement relative to each other. In addition, all types of concrete are not resistant to bending, namely, they appear with uneven shrinkage. If the foundation is not made correctly, inclined cracks will go along the walls.
- The construction of such wall material gives less load on the base than the construction of walls made of brick or concrete. But here it is important to correctly calculate and choose the foundation. Fencing from foam blocks is about two times heavier than from a tree, so there are some limitations on the choice of supports (difficulties mainly arise when erecting on piles, both screw and bored).
To choose a foundation for a house from foam blocks, you need to consider the following characteristics and requirements:
- bearing capacity of the foundation soil (with the definition of this characteristic, the calculation of the supporting part of the building begins);
- load from overlying structures (for a two-story and a one-story house, different choices should be made);
- the need for a basement device (if the underground floor is needed, then such types of supports as screw piles, bored piles, shallow and shallow bases are not suitable);
- climatic features of the area (here a phenomenon such as frosty heaving plays a role, on which the depth of the base part of the house will depend);
- the location of groundwater in the soil (it is important that their level is at least 50 cm from the bottom of the foundation, this is not relevant if construction is carried out on screw or bored piles).
As can be seen from the above, the foundation for the house of foam blocks is not an easy task. To choose it correctly, you will need to take into account the influence of several factors at the same time and not to forget any of them.
Strip foundation
The foundation for the house of tape-type foam blocks has two classifications. The first depends on the depth of the laying:
- shallow;
- shallow;
- buried.
The first is not used for massive buildings, so in this case it will not work. In the second case, you need to perform the correct calculation of the base. In this case, the cross section of the tape can be of two types:
- rectangular;
- t-shaped.
The shallow depth of the base is suitable when there is no need for a basement device. In this case, the thickness of the layer of soil freezing during the winter period must be taken into account. When leaning on a soil prone to frost heaving, it is worthwhile to provide insulation of the tape. For a two-story building, it is recommended to use a t-type type of supporting part. The large width of the sole allows you to better distribute the load. Do-it-yourself construction of a one-story house is also best done with a widening of the base.
The use of a recessed strip foundation is justified if a basement is required. Depth depends on the height of the room and freezing of the soil. It is important to control the location of the groundwater level, if it is closer than 3 meters to the surface of the earth, additional measures for waterproofing and water disposal will be required. The cross-section of the tape base in this case for a two-story building is assumed to be rectangular. The large width of the sole is selected by calculation, the need for it arises only for buildings with large floors.
The width of the main part of the support depends on the thickness of the walls. If possible, it is selected a little more than the building envelope, but let's say the overhang is not more than 3 cm.
Slab foundation
The stove is one of the most versatile bases. The width is assigned so that the edges of the supporting structure extend beyond the outer walls by 10 cm. Calculation of the bearing capacity is performed in order to determine two characteristics:
- thickness
- reinforcement.
The types of slabs, depending on the depth, are the same as for the tape. Depth is assigned depending on whether the basement is designed in the house or not. Also, a slab foundation of foam blocks allows you to build a house with your own hands in areas where the water level in the ground is elevated. The maximum distance from the liquid horizon to the surface can be up to 50 cm (in this case, an unfilled plate option is poured).
Column foundation
Pillars do not differ in high bearing capacity. When using them, you will need to perform a calculation of the bearing capacity, which will determine:
- sole sizes;
- distance between adjacent supports.
You can do the calculation yourself, but you will need to collect the initial data, which include:
- bearing capacity of soil;
- load from overlying structures;
- dead weight of the supporting part (preliminary).
Unfilled pillars cannot be used; the use of shallow-deep supports for the structure of foam blocks is carried out with caution.
On a columnar basis with pile foundations, it is important not to forget about the device of the grillage (from metal or reinforced concrete).
Pile foundation
Piles are different. With self-construction, they most often use:
- screw;
- bored.
The construction of a private house on stilts should be carried out with caution. Now popular screw supports with a diameter of 108 mm can withstand 4-6 tons each (depending on soil characteristics). Such a pile foundation is not suitable for a massive house of more than one floor, the calculation will give an excessively small step of the supports (frequent location), which will lead to an increase in cost. When building an object from foam blocks into two floors, a larger diameter of the screw pile will be required.
The advantage of building the device on a pile foundation is that not only the supporting part (the end of the pile) but also the lateral surface perceives the load. When using the foundation on screw piles, the average laying depth is in the range of 2 to 3 meters. It is this value that is most optimal for a small private structure.
Pile screw foundation is especially relevant when work is carried out on marshy terrain. Piles can ensure the reliability of the object, even on soft ground. At the same time, they try to choose the length so that the bearing is carried out on the soil with good characteristics. The benefits of building on stilts include:
- Low cost of the supporting part. This is a particularly relevant plus that can be provided by piles, because for some types of bases the estimate can reach up to 30% of the cost of the whole house.
- The foundation on stilts does not require large labor costs. You can run it in a shorter time. This quality relates mainly to those objects on which metal piles are selected.
- Also, for construction on screw-type metal piles, it is not necessary to wait for time for the foundation to build strength, as is necessary in the case of reinforced concrete structures. Thus, the completion time of the facility can be reduced by several weeks.
The calculation of the foundation on piles is most often carried out with the already set diameters of the supports and their long. The maximum distance between the individual elements is calculated.