How to repair a crack in a plaster wall?
When starting repair work, many people face the question: how to close a crack in the wall? Such defects are often encountered when re-gluing wallpaper or when preparing walls for painting. Cracks can have different geometry and sizes, they are superficial and through. If a crack is found, it is necessary to immediately carry out restoration work, because if everything is left to chance, then over time the damage will increase in size and lead to peeling or deformation of the finish coating, which will negate all your work.
Causes of cracks in the wall
Cracks in the wall occur for many reasons, which can be associated both with certain mistakes made during the design or construction of the facility, and with natural factors beyond the control of a person. All the reasons why cracks can form can be combined into several groups:
- shrinkage of the building;
- engineering errors or violation of construction technology;
- improper use of leveling solutions.
The most common cause of wall damage (especially for low-rise buildings) is the uneven shrinkage of the building. In the first few years after the completion of construction, the house, under the weight of building materials from which the walls, floor, ceiling, roof and foundation are made, settles into the ground. If shrinkage is uniform around the entire perimeter of the foundation, then it does not lead to cracking and is considered normal. If the building sinks unevenly into the ground, then over time this will certainly cause undesirable consequences in the form of cracks on the wall, skewed doorways, window frames, etc.
Such phenomena must be constantly monitored with the help of beacons mounted on damaged areas. As beacons, you can use plain paper, which is glued to the crack with glue. If the paper does not tear in a week, then there is no reason to panic. In this case, you should simply close the crack in the wall.
If the paper breaks, and according to the calculations, the shrinkage should have stopped long ago, then the point here is not in the subsidence of the house, but in violation of the construction technology. At the same time, simply repairing the damage with a mortar will not give a positive result, since the cause of the defect will continue to negatively affect the house.
The safest and most easily correctable cause is improper preparation or application of leveling compounds. In this case, nothing threatens your home, except for the loss of an attractive appearance.
In addition to the above reasons, the factors that negatively affect the design of the house should also include phenomena that do not depend on the person:
- rising groundwater levels;
- temporary destruction of the foundation;
- a strong slope of the site, as a result of which uneven loads will act on the building;
- various weather events (heavy rains, snowfalls, gusts of wind, earthquakes, etc.).
How to repair a crack in a plaster wall?
Cracking of plaster is a fairly common phenomenon that can be observed both on the exterior and interior walls of the house. Especially often such damages are formed when using a cement-sand mortar as a plaster.
Before you close a crack in the wall, you need to prepare the following tools and materials:
- putty knife;
- brush;
- sickle tape;
- primer;
- plaster mixture;
- sandpaper.
The procedure for repairing cracks in plaster begins by widening and deepening them with a small spatula, kitchen knife, screwdriver, or other sharp object that you feel comfortable working with. This allows the repair solution to penetrate deep into the damage and fill it better.
At the next stage of restoration work, the defective area is cleaned of construction debris and primed with a brush and a deep penetration primer. Treating a crack with a primer increases the adhesion of the plaster mixture and, accordingly, the strength of its adhesion to the base. After the primer has dried, the plaster mixture is carefully rubbed into the crack with a spatula. Until the solution has set, a serpentine tape is applied over it along the entire length of the gap and closed with the same solution. As a repair mortar, it is recommended to use a gypsum mixture, which can be purchased at any hardware store.
After the plaster has dried, it must be rubbed with sandpaper to obtain an even base. Your wall is ready to be wallpapered, painted or finished with any other decorative material.
Repairing cracks in brickwork
There are several ways to fix a crack in a brick wall. The choice of one method or another will depend on the size of the damage. How to close a crack up to 5 mm wide? To do this, you can use ordinary cement mortar or tile adhesive. Before applying the selected mixture, the crack must be widened with a spatula and hammer, cleaned of debris and treated with a deep penetration primer. Slots up to 10-15 mm in size can also be sealed with cement mortar. Only in this case it is recommended to add a little fine sand to it.
Slots with a width of more than 15 mm are considered dangerous, as they reduce the reliability of the brickwork and can lead to a partial collapse of the wall. To repair such damage, other methods of restoration work are used. For example, a defective section of a wall can be dismantled and replaced with new masonry. At the same time, the installation of bricks is carried out using the “brick lock” method.
To increase the strength of the masonry, pieces of reinforcement are laid between the rows of bricks.
A large gap in the brickwork can also be sealed with foam. To do this, the crack is cleaned of debris, primed and filled with foam. After setting, the foam is cut to a depth of about 20 mm. This gap is filled with a cement mixture or adhesive.
A crack in the wall can occur for many reasons. However, no matter what factors lead to such a defect, it must be repaired without fail before finishing the wall, because after a while the gap can cause damage to the finish.
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