Cracks in the walls can appear for various reasons. Cracks may not be dangerous (which simply spoil the appearance), but can seriously threaten the integrity of the walls and the stability of the entire structure.
The sealing of cracks in the wall is carried out in various ways, depending on the depth and degree of surface destruction. Do not think that independent sealing of cracks is inappropriate – if everything is done according to the instructions, observing the main aspects of the work, then we can avoid all kinds of problems and troubles in the future.
The sealing of small cracks (we are talking about cracks in plaster and putty) begins with cleaning the crack itself from dirt and exfolved particles. The crack is expanded to solid material, dust is removed with a brush, washed with water from a spray gun or brush. Then the crack is sealed with a liquid gypsum solution. Gypsum is collected on a spatula and rubbed into a crack, trying to fill the entire cavity, then pass the entire crack by the spatula across, removing the excess gypsum and leveled the layer. After drying, gypsum is cleaned with sandpaper.
The sealing of cracks in the wall formed as a result of precipitation of the structure is conducted by a lime-cement mortar (we are talking about large and deep cracks). A strip of plaster about 10 cm wide is carved along the crack, the seam is cleaned, moistened and filled with a solution, thoroughly compacting it. Fragments of bricks are laid in wide cracks along with the solution. After the solution hardens, the cleaned strip is plastered on a new one.
Cracks that arose on the border of heterogeneous materials (for example, wood and concrete) are closed to the entire depth of cement-license solution, covered with a mesh on top and plaster is applied.
When sealing very large cracks, you must first verify the integrity and stability of the structure, take measures to eliminate the causes that led to the appearance of a crack. The seal is carried out by a sand-cement mortar in a ratio of 1: 2-1: 3.
If the crack continues to open, then it can be strengthened with epoxy resin. Outside, the crack is covered with a cement mortar (if necessary on the grid) and leave the hole in the upper part through which the resin is inserted along the tube.
Cracks in brickwork can be strengthened using metal brackets. The brackets are installed along the entire length of the crack, perpendicular to it. The depth of sealing brackets should be 1/2-4/5 wall thicknesses. The length of the brackets should be such that the brackets are burying into the wall at a distance of 50 cm from the crack. The brackets are installed in drilled holes for a cement mortar.