What to do if the foundation is cracked?

By Admin | Recommendations
15 May 2016
If your house is built by permanent formwork, made of bricks, lightweight aggregate concrete, or foam / concrete blocks diagnostikatreschiny wall is conducted as:

First you need to put beacons from a tile adhesive or cement-sand mortar, with need to put in the clutch rather than plasterat the beginning and end of the crack.The lighthouse is done in the form of eights, top and bottom which are based on the crack, and the middle, passes through the crack.Usually cleave "cake" made from a solution, but it falls off from the edges of the crack, and did not manage to find out how the crack grew.

Continuing, one bimonthly journal written observations of the state of the lighthouse (not cracked or cracked lighthouse and crack width in mm.) And draws a graph.It should be noted that if the crack width for the year increased to 15-20mm is unpleasant, but not in danger of collapse.

Examples of observational results for the year:

month development of a crack in the wall of 3-5 mm.In just a few months is not
observed attenuation - it is necessary to take urgent measures to strengthen the ground structures and foundations.

development of cracks during the year 15-20 mm.If not observed attenuation process - need to strengthen the foundation and walls.

During the year a slight increase in the cracks of 1-5 mm.As soon as possible to stabilize the process.And if in the next 3-5 years is not observed attenuation - it is necessary to strengthen the foundation and the ground structure.

cracking occurred lighthouse on a small-size 0.5 mm.- Okay, this temperature change.





dangerous - if the crack in the stone structures reach - 50 mm, the slab has shifted from support to 30 mm, wall deviate from the vertical by 1/5 of its thickness.



Common errors in the construction of foundations and ways of solving these problems


Diagnostics rainfall foundation for wooden houses: frame, wood and lumber

Wooden building houses especially the least susceptible to shrinkage of the foundation.But despite this foundation settlement it appears as skewed windows, doors, floors.Typically, in such cases, the house does not falls unless offset beams, if they are not nailed.

If the crack in the foundation of 3-4 cm in the 10 meters of its length, and there are no visible distortions in the building, do not worry about it.

But if your house is on the pier foundation, then you need to check the slope of the pillars.If they fall down, you need to put the house on the other foundations, for example, on steel piles.


Note
In those cases where a strengthening of the foundation, do not do it yourself.It is better to invite a specialist otherwise the situation could get worse.



Melkozaglublennaya tape

cause damage and deformation:
  • emergence of strains from the impact forces of frost heaving of the small thickness of the sand cushion;
  • No drainage sand pillows;
  • Poor reinforcement concrete foundation;
  • different density training (cushion) foundation;
  • Grunt becomes stronger as a consequence of heaving sand silting training.
The solution in accordance with the reasons
  • At high groundwater might help the drainage system and the device warmed blind area;
  • necessary to make drainage;
  • If the house is wooden it strengthens nails.And if the house reinforce the foundations and walls of prestressed steel strands;
  • Draught House is likely to stabilize;
  • necessary to rearrange the house on piles.


svaynorostverkovy foundation in steel and reinforced concrete design

cause damage and deformation:
  • frost heaving forces act tangentially to the lateral surface of the pile;
  • Base at the edge of an inhomogeneous pile;
  • Insufficient thickness of the foundation or bad its reinforcement;
  • Installation tip piles above the freezing depth;
  • Rostwerk silnopuchinisty rests on the ground.
solution to the problem in accordance with the reasons
  • insulated foundation and warmed to make blind area.Or dig around the pile and replace the soil to coarse sand, plus drainage and pre-wrapped pile polyethylene fluff and bury them with grease;
  • sags on site to install additional piles;
  • Install additional piles;
  • Remove old pile raft foundation and put on new ones.Or warm blind area and the foundation;
  • between the raft and the soil to dig slit or insulate the blind area.


foundation on piles

cause damage and deformation:
  • Dangerous for strongly rubbing the top stratum of soil;
  • Base heterogeneous;
solution to the problem in accordance with the reasons
  • not do near the house parking lots with concrete slabs.Do not make podsypku territory (10-15 cm);
  • Make extra piles in the ground subsidence at home.


Belt foundation laid below the freezing depth

cause damage and deformation:
  • foundation unevenly loaded or ground with insufficient bearing capacity;
  • depth laying the foundation above the freezing depth;
  • the forces of frost heaving on the lateral surface of the foundation;
  • Poor reinforced foundation, no protivoosadochnyh zone in the aerial parts of the building;
  • building is not used in winter.Throughout the winter in the basement open door or window.
solution to the problem in accordance with the reasons
  • broadening soles strengthen the foundation micropiles device (not suitable if the soil-peat or silt);
  • insulate the blind area;
  • Replace backfill nepuchinisty on the ground or insulate blind area and the foundation;
  • strengthen the foundation and walls;
  • Reside in the winter in the house.




monolithic concrete slab


Problems are solved similarly MZL.


Foundations wetland

wetland drainage is not recommended, as it will exacerbate the situation.Similarly - if the person is in a bathtub full of water, it floats, and it does not press his weight, and when the water goes down the pressure from the body in the bathroom increases.Making the drainage you get rid of the weighing action of water in the soil.

It is possible that the sediment of your home is connected with the organization of drainage from your neighbors.


strength of the concrete should be at least 10-15MPa Bat.Here is a table to assess the strength of the concrete.

approximate estimation of concrete strength by tapping the surface with a hammer

results of one strike of medium strength with a hammer weighing 0.4 - 0.8 kg.
Concrete strength MPa
directly on the concrete surface
By chisel set "sting" on concrete
on the concrete surface remains weak track, around which are thin sliver leschadki.

shallow footprint leschadki not break off.


more - 20
on the concrete surface remains weak track, around which are thin sliver leschadki. break away from the concrete surface leschadki sharp. 20 - 10
concrete to crumble and fall off when you hit the edge, break off large pieces.

remains a deep impression
chisel penetrates into the concrete to a depth of 5 mm, concrete crumble.

chisel is hammered into the concrete to a depth of 5 mm.
10 - 7


Less - 7



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Editor: Roman Adamov