10 important reasons why the foundation sank
Foundation settlement is a process that involves the displacement or lowering of the foundation of a building below the design level. Such a defect requires repair and most often occurs due to the fact that the bearing capacity of the soil gradually decreases. In general, the reasons that contribute to the occurrence of this problem can be characterized as follows:
- Geological research errors - if construction began without prior soil survey, or the research was carried out poorly.
- Groundwater rise - a change in the hydrogeological situation leads to the washing out of the soil layer from under the foundation.
- Frost heaving of the soil - an increase in the volume of the soil due to its freezing in a wet state.
- Errors in the operation of the drainage system - damaged drain pipes, lack of drainage, waterproofing, oversaturation of the soil near the foundation with moisture.
- Errors in the design of the structure - incorrect calculations, insufficient depth, incorrectly selected type of foundation (foundation slab, strip, pile).
- Unauthorized increase in load - addition of an attic or additional floors, roofing made of heavy materials that cause shrinkage of the structure.
- Mechanical and vibration loads - intensive movement of freight transport nearby, operation of special equipment, etc.
- Chemical impact - destruction of the structure of the base due to the action of aggressive groundwater with an increased concentration of salts, acids, alkalis.
- Compaction of the bulk layer of earth - use in the construction of old man-made soil for paving, which shrinks over time.
- Excavations or construction carried out nearby - digging pits, trenches nearby.
The main signs of foundation subsidence are the appearance of vertical, horizontal and diagonal cracks, the width of which indicates the degree of deformation of the base. Also, the need for repairs will be indicated by windows and doors that have begun to close poorly. Moisture and mold appear on the floor covering, and the floor itself begins to creak when walking on it. It is also worth paying attention to obvious deformations on the foundation, which are manifested by peeling plaster, destruction of brickwork, subsidence of individual areas.
How to avoid foundation settlement
To prevent subsidence of the foundation of the house, it is extremely important to carry out engineering calculations as accurately as possible and adhere to the prescribed technologies during the construction of the house. Preventive actions that will help prevent subsidence of the foundation of the house can be conditionally divided taking into account the peculiarities of construction and operation of the facility. During the design and preparation for the construction of the building, it is worth paying attention to the following:
- geodetic examination - accurate determination of the type of soil and the level of groundwater;
- optimal depth of foundation laying - the sole of the foundation should be below the level of soil freezing;
- accurate calculation of loads - the mass of building materials and the number of storeys of the structure must be taken into account.
During construction, it is necessary to pay attention to the quality of the selected materials, the concrete should be of the optimal brand and with the presence of certified reinforcement. Those who ask why the foundation cracks should know that during pouring it is extremely important to withstand the technological cycle, allowing the base to gain strength before the construction of the walls.
During operation, experts advise making a blind area around the perimeter and installing storm sewers at a safe distance from the house.
Equally important will be monitoring the operation of the water supply and sewage system to prevent hidden leaks and flooding of the soil.
