A Foundation on poles with their hands. The main errors in the calculations
The construction of the Foundation is the initial and one of the most important stages in the construction of any building. The quality of these works will largely depend on how long the stand structure.
There are several typical mistakes made by inexperienced builders:
- Errors in calculations;
- The use of substandard or unsuitable material properties.
When using Foundation, the Foundation which serve as the pillars, it is necessary to carry out calculations correctly, as they will determine how much area of contact with the ground must have support. This is necessary in order to evenly distribute the load on the ground, as in the operation of the home will become more and more high weight, and, consequently, the load will grow.
Errors in calculations can lead to the fact that over time, the Foundation and, accordingly, the house itself:
- will shrink unevenly;
- from the floor you see the effect of the spring;
- the wall can go cracks;
- the house may be.
When using a Foundation on poles, tape casting, which takes place between them, is not an element that take part of the load transmitted to the ground. This fill is only needed to give additional stiffness of the whole structure of the Foundation.
Example of calculation: Foundation pillars for the house size of 10 x10 meters has 30 pillars, the parameters of each of them are 40×40 cm. Therefore, the area of contact with the soil is 1600 sq cm the Soil on which it is planned to build a house, is a clay loam. According to reference data such soil can take the load without any damage to the building that is constructed, no more than 124 tons.
To build the Foundation of such a house all the regulations, you need at least 20 cubic meters of concrete, the weight of one cubic meter of concrete is 2.4 tons. If you multiply this figure by 20 cubic meters, you get 48, etc
To this figure must be added the weight that will have a plinth of brick. The ground area is built at least 8 rows of bricks with a thickness of one layer. Single bricks with mortar weighs about a kilogram, all bricks need 8000 from this it follows that the whole cap will be not less than 8 tons.
Together, the weight of the Foundation of the house in the preparation of the weight part of the basement and Foundation is no less than 76 tons. And it’s about 40% of the maximum allowable weight that can withstand the Foundation on this soil.
On the basis of the example calculation, it can be concluded that this type of Foundation with the settings for this type of soil is not suitable as a one-storey house with a total area of 100 square meters is not less than 200-250 tons.
If the building will still be built on the Foundation of such parameters, which is not really suitable for this type of soil first, nothing will happen. But after the first shift of the cycles of the seasons can be quite significant changes that will eventually lead to the appearance of cracks in the walls and the destruction of the building, the service life of such structures will be significantly reduced, instead of 50-100 years, this house will last for more than 30 years.
The use of substandard or unsuitable materials
The quality of the materials used is also of great importance in the construction of the Foundation of the house. Because even if calculation errors there, but the material used will be of poor quality result from the construction of this house will be the same as when errors in calculations.
Rebar, which is used when laying the Foundation must be pre-processed to have a desired thickness. And in the manufacture of concrete mix you must use only high-quality cement are not worse than brand M500. This is necessary in order for the concrete to get a solid and withstood all loads.
You also need to pay special attention to the characteristics of the soil that will be home. If, for example, a loamy soil, it really absorbs and releases moisture. So, in winter, it will become swollen, and in the summer, possible penetration of groundwater from the basement through the capillaries blocks. From this it follows that palomaki without prior waterproofing of the Foundation can not be used, since they are hygroscopic and exposed to moisture tend to deteriorate.
Summing up, it should be noted that the construction of the Foundation – a very demanding job. If in case of an error in the masonry it will be possible to disassemble, fix the Foundation after pouring is virtually impossible. Therefore, before starting any jobs, make sure that all calculations are correct, and the materials and fit are of high quality.