- Construction errors leading to cracks in the house
- How to determine the type of crack
- We remove cracks in the house that can destroy it
- Redecorating cracked walls
Very often, homeowners encounter cracks on the walls, some creep like cobwebs on the putty, but there are also cracks tearing the building apart. Knowing the true reasons for their appearance, you can stop their growth, and then proceed with the repair and decoration of the house..
Construction errors leading to cracks in the house
The old private houses were built by the owners who used the help of family and friends. Sometimes they did not even have a specific plan, so the houses were built without calculations and were ill-considered upset by the addition of separate rooms. Information on how to properly make a foundation or reinforce concrete was also lacking.
Often, some believed that the more iron in the foundation, the better. Such a base was reinforced with anything, up to pieces of tin and any scrap metal. The second common option for building a foundation, leading to the appearance of cracks, is the complete absence of reinforcement. The base of the house was laid out of brick or wild stone, without taking into account the peculiarities of the soil on which it was built.
All this led to the fact that many houses began to sink over time, the foundations cracked, and the outbuildings moved away from each other, forming rather large and dangerous cracks. Some of them appear, but over time they stop growing and do not require strengthening the foundation. To determine the method of correcting the defect, you must first find out whether the crack threatens to collapse the wall or not, and then establish the cause of the crack.
How to determine the type of crack
Cracks are superficial, in which only the plaster layer cracks, and through, passing through the entire thickness of the wall. To find out the type of damage, it is necessary to establish whether the crack continues to grow or if it is already established and does not change in size.
This is determined using glass beacons. A narrow long strip is cut out of thin glass, which is fixed with plaster at its ends on both sides of the crack. The center should remain clean and over the crack. It is better to knead the gypsum thicker to make it easier to glue the glass. Its walls are so smooth that the ends of the glass beacon are constantly slipping, so you need to hold it with your hands for a few seconds until the plaster hardens completely.
Signs for determining the depth of cracks:
- surface (removable by cosmetic repair) – after a month, the glass remains intact. Such a crack has already stopped and is not enlarging;
- destroying the house (requiring major repairs) – the glass broke within a month. The discrepancy continues and it is necessary to look for the reasons for this process and urgently eliminate them.
The most common reason for the appearance of such cracks is the violation of the integrity of the foundation and soil subsidence. Destruction occurs with loose soil or a small foundation area that is not designed for the weight of the walls. Sometimes the base is eroded by groundwater. If you do not restore the strength and integrity of the foundation and do not exclude its further subsidence, it will be impossible to repair the cracked wall. No matter how many times it is plastered and no matter how it is strengthened, the crack will appear again.
We remove cracks in the house that can destroy it
You can strengthen the foundation in different ways, but the most reliable is to make it solid again with the help of proper reinforcement and increasing the area of support on the ground. To achieve this, you need to dig a trench about one and a half meters long and 40-50 cm wide close to the foundation. The depth should be about 40 cm below the foundation, but not less than to the freezing point.
Then we remove the soil from under the foundation, to the level of the bottom of the trench. This will enable the concrete to spill under the old base and increase its area almost twice, while reducing the load on the ground by the same amount..
We reinforce this space with reinforcement rods with a thickness of at least 14 mm, laying them horizontally along the foundation and sticking the ends in both sides of the trench by at least 20 cm. There should be from six or more such rods. Two rods at the very bottom, two in the middle and two on top. Such an arrangement of reinforcement in the foundation makes it work not for bending, but for breaking, which is ten times more effective..
We drill holes in the foundation in order to drive pieces of reinforcement into them and weld them with the rods laid earlier. Then we fill this trench with concrete, making sure that the solution fills well the void under the foundation. Ideally, it is recommended to use a vibrator for this, but if this is not possible, you should vibrate the concrete well by hand using a long rod.
Several such trenches must be made under the wall, the number is determined by the distance. The gap between the trenches should be about two meters. After the concrete has set (usually two weeks are enough for this), you can start digging the same trenches between the resulting new foundation blocks.
By digging out the following trenches, you will free the ends of the reinforcement rods (which were previously driven into the ground by 20 cm) and you will be able to connect separate blocks of the new foundation into an integral reinforcement belt, using welding and two-meter pieces of rods.
After filling all the trenches with concrete, you will get a strong new foundation with an increased area of support on the ground and tightly connected to the old foundation. Now you can safely start repairing the crack itself, since the new reinforced foundation will no longer allow the wall to disperse.
To repair a crack, first of all, you need to clean its edges from such parts of the wall and plaster that can hardly stick. Then it must be filled with some kind of mortar, the choice of which depends on the width of the crack and the building material from which the wall is made..
If the size of the crack is small, the easiest way is to fill it with polyurethane foam, followed by plaster and putty. When the crack is large, the hole is filled with the material from which the damaged wall is composed, with further finishing.
The most difficult repair is a crack on the wall, which is lined with finishing bricks. Before laying, broken bricks are knocked out, and new ones are put in their place, adjusting the masonry according to the pattern.
Redecorating cracked walls
If the glass beacon showed that the crack was no longer parting, there was no need for such a complex repair. It is enough just to make a cosmetic.
To do this, the crack must be processed, removing all the pieces that do not hold well, and filling it, as described above. When the hole is closed, the surface is plastered and putty. In this case, it is recommended to use a construction mesh for plaster.
The mesh must be glued to the crack so that its edges go over the sides of the crack by ten centimeters and only then plaster this place. The mesh will create additional reinforcement and prevent the appearance of new microcracks from shrinkage of the material.
Also, when renovating a house, one sometimes has to deal with microcracks that appear on normal and well-reinforced walls due to thermal expansion. This is usually due to the fact that a reinforcing mesh was not used when they were putty. It is best to completely re-putty such walls, reinforcing them with a mesh. This will ensure that microcracks will not appear in the future. But if this is not possible at the moment, you can use elastic putty mixtures to repair such defects..
Do not try to fill large cracks with foam or other materials, as you will accelerate its expansion. Through cracks are the most dangerous and their strong divergence leads to the collapse of the floor slabs. This method can only be used temporarily to survive the cold season, during which major repairs are difficult to do..