The choice of the type of foundation will depend not only on the features of the future building, but also on the characteristics of the soil, which should be learned before construction begins. For utility and other buildings with low weight, columnar foundations are considered to be the most suitable and most suitable.
You can create them from a variety of materials, and the technology may vary, but the common feature is that the base will be supports, deepened to the required level. Pillars can be laid out from blocks that are cast from reinforced concrete. Sometimes supports are made of metal pipes.
Important to remember
A columned foundation of 20x20x40 cm blocks does not provide for a basement. If this criterion is important for the future owner, then you should pay attention to other types of grounds. The most suitable depth of the foundation is 1 m, but if the construction conditions require a more impressive depth, it makes sense to consider the possibility of building the foundation from asbestos-cement pipes filled with concrete. After all, laying FBS blocks to a depth of more than 1 m is a very time-consuming process. A more impressive depth can be dictated by some construction conditions by the type of mass of the house or the type of soil.
When to abandon the column foundation from FBS blocks
In some situations, it is necessary to abandon the columnar foundation where FBS blocks will be used. Such restrictions are expressed in the construction of massive buildings, the walls of which are made of heavy materials, such as reinforced concrete wall blocks or bricks. You should not use such a base on soils that have not so impressive bearing capacity, among them:
- subsidence;
- clayey;
- water saturated.
Moving soils are also not suitable for such a foundation, because they have low resistance to horizontal displacement loads. If on the territory there are natural height differences of more than 1 m, then it is required to level the soil in advance.
Area of use
Do-it-yourself pillar foundation of blocks is erected by private craftsmen. These bases have limitations in operation and potential. They can be erected on loosely soiled soils or soils that are not prone to heaving. After the construction of the base, you can start the construction of a panel building, which is usually a one-story building.
If you have started construction in a region where coarse-grained, dense rocky or sandy soils, the bearing capacity of the foundation from FBS will be enough to build a full-fledged house from foam concrete, timber or log house. Boulder, gravel and pebble soils are excellent for such construction.
Block selection
Before you make a columnar foundation of blocks, you need to choose the material. For this, products with the FBS marking are suitable, the manufacturing technology of which should be regulated by state standards 13579-58. Having familiarized yourself with the norms, you will be able to understand that concrete of the M-100 grade or higher is used for the production process, as well as a mesh, the sizes of which are quite wide.
If you are faced with the question of how to make a columnar foundation of blocks correctly, then you should find out that reinforced concrete structures are quite large-sized. They are laid with a construction crane, because the weight can reach 2 tons. Such blocks are reinforced with reinforcing cage made of hot-rolled reinforcement of grade A3. The diameter of the rods will depend on the size of the blocks and varies from 9 to 15 mm. If we are talking about large-sized blocks, then they can be used for tape and slab foundations, on which massive brick structures will subsequently be installed.
Large-sized blocks in private small-scale construction are rarely used, because their weight does not allow for manual masonry, for this it is necessary to rent a construction crane, which reduces the advantages of the foundation and the cheapness to nothing. For manual masonry, it is better to use FBS, based on expanded clay concrete. Such products differ in low weight, as well as heat-resistant characteristics. Quite often, the construction of a columnar foundation of blocks 20x20x40 cm is carried out for the reason that these products are the most popular, and their weight is 32 kg.
Technical characteristics of FBS blocks with dimensions 20x20x40 cm
FBS are excellent for creating columnar foundations; they have a nominal strength of 150 kg / cm 2 . Frost resistance is quite large and amounts to 15 cycles, and the ability to absorb moisture reaches 15% of the total volume. The thermal conductivity of the products is 1.16 W / mK. If you are thinking about how to build a column foundation from blocks of 20x20x40 cm, then you should take into account the advantages of using such products, they are in the high speed of the work, as well as the possibility of using a special adhesive composition or cement-sand mortar.
In this case, all the work can be done independently, without resorting to the help of construction equipment. However, similar products also have drawbacks, they are expressed in low hydrophobicity, because expanded clay concrete blocks have a porous structure, as a result of which they absorb moisture from the soil like a sponge. In the future, this may cause the destruction of the block.
Features of the columnar base of blocks
The column foundation of blocks is suitable for buildings based on a wooden frame. In this case, you do not have to lay concrete, which sometimes plays a decisive role. Formwork is also not required, so there is no need to import a large amount of crushed stone onto the site, this also applies to other building materials. It will only be necessary to prepare concrete blocks, the recommended size of which is 20x20x40 cm. This technology allows saving on construction and is relevant in cases where it is not possible to bring electricity to the site for the concrete mixer to work.
Specialist advice
If you need to build a bathhouse, garage or utility building, and the project is limited both in terms of implementation and financial capabilities, then the column foundation will be the best solution. It is suitable for any other small building, in addition, the construction can be completed in the shortest possible time. You can use not only blocks, but also bricks, wooden poles and asbestos-cement pipes. Such bases have high bearing capacity and durability. You can use FBS, which are presented on the market with reinforced concrete or expanded clay concrete products of factory production. They are made by vibrocompression and are great for this purpose.
Preparatory work
If you decide to build a columnar foundation of blocks, then first you need to prepare the site, for this it is leveled, freed from garbage and removed the top layer of soil. Its thickness can range from 25 to 30 cm, everything will depend on the slope of the site.
Once the place is ready, you can proceed to the marking, for this, pegs are installed in the corners of the future building, the diagonals are measured, this will make sure that the angles are set correctly. Pegs should be located in those places where the walls will intersect, the connection of the stakes is carried out along the line of passage of the walls with twine.
Excavation
The column foundation of the blocks requires wells for the installation of poles. To do this, it is better to use a hand drill, going deeper to the desired mark. You can expand the pit with a shovel. When using concrete blocks with the above dimensions, the dimensions of the well should be as follows: 50 x 50 cm. The depth will depend on the climate in which the construction is carried out.
It is important to take into account the depth of freezing of the soil. If in your region it is equal to 50 cm, then you need to deepen into the well by 90 cm. Once the wells have been formed in all corners, you should also dig holes at the intersections of the walls. Then the recesses need to be located under the future walls, the distance between the pits should be 2 m. If you decide to build a columnar foundation of blocks, then at the next stage you can proceed to the formation of columns.
Work on the supports
Crushed stone is poured at the bottom of each pit, which will serve as a drainage layer. This is especially important during seasonal temperature changes. Once the preparation is finished, you can make a pillow from the solution on which the first blocks are installed. The next two need to be laid on top, placing them perpendicularly. The less you make a seam between the stones, the more reliable the foundation will be.
The posts should be raised so that they rise 30 cm or more above the surface of the earth. It is important to control that the surface of such supports is horizontal. After laying all the pillars they need to be protected with a layer of waterproofing. This will protect the base from moisture, which can wash the mortar from the masonry and destroy the blocks under the influence of low temperatures.
Conclusion
If you still cannot decide whether to build a shallow columnar foundation from blocks, then you should think about the fact that the minus hydrophobicity of these products can be solved by waterproofing the base. The minimum distance between the supports should be 1.5 m. And if construction is carried out on problem soil, the step can be reduced to 1 m.