Crack Filler for a Concrete Building

Causes of Concrete Cracking

• Concrete, though a strong building material, can be affected by environmental forces. Shifting or heaving of the soil beneath the structure can cause separation of joints. Uneven loads can cause pressure in opposing directions, causing cracks at junctions of the materials. Concrete also expands and contracts with fluctuations in temperature. This action often causes cracking. Concrete suffers natural shrinkage that can cause cracks in the surface as well. The composition of the concrete itself can be a source of cracking, such as when too much water is used or when the concrete has been improperly cured, according to the GharExpert website.

Concrete Patch Compounds

• A number of concrete matching materials are available. Common concrete patch compounds can be used to fill and cover small cracks in the surface of the building. Generally, cracks under ¼-inch wide can be easily filled with these patching materials. They are available in both dry and pre-mixed forms. The dry form must be mixed with water. The cracks in the building must be carefully cleaned, removing all loose materials as well as grease and dirt. A thin mixture of the patch compound is painted onto the crack as a “glue.” The full-strength patch compound is pressed into the crack, and the surface is smoothed with a scraper or trowel. The patch compound is allowed to dry thoroughly.

Plastic Patch Compounds

• Repair compounds that contain plastic ingredients are also available for concrete repairs. These materials can be used on holes and chipped edges to fill in damaged areas. Plastic patching materials contain vinyl or concrete for fast-setting repairs on concrete surfaces. Use a thinner mixture for cracks and a slightly thicker consistency for holes and depressions, advises The New York Times website.

Epoxy Injection Repair

• Epoxy injection is a method used for deep cracks more than ¼-inch in width. This type of material is injected into the crack and left to harden for a quick and long-lasting repair of the surface. The crack must be cleaned and the surface of the crack prepared by brushing it with epoxy. A seal is placed over the cracked surface. Holes are drilled along the cracks, and the epoxy injected under pressure into the holes to fill the cracked area. Drilling a V shape into the crack is often recommended to hold the materials securely. The epoxy is allowed to dry and the seal removed for a clean, smooth repair.