How to Repair Concrete Cracks
Concrete is among the most reasonably priced and durable building materials utilized in modern construction. Most common among its numerous applications are building foundations, sidewalks, patios and flooring. While it can be expected to last for many years, such things as improper placement, earth settlement, water seepage and tree roots can cause cracks in a concrete structure. Many can be repaired quite simply by the average homeowner.
- Hairline cracks (smaller than 1/8 inch), can be corrected by following these steps:
- Carve a notch along the length of the line using the edge of a flat screwdriver. This groove will allow the repair material to set.
- Brush away the resulting flakes and crumbs of loosened concrete to ensure adherence of the repair material. If you have one, a small air compressor works well for this process. Wash the area with a water hose.
- Apply a string of concrete patch compound with a caulking gun and push it into the crack with a putty knife. Smooth the compound over the surface.
- Allow the repair to dry thoroughly before subjecting it to any use.
For larger cracks, repair is the same with the exception of the indentation process. In this case, change Step 1 above as follows:
- Using a hammer and cold chisel, carefully widen the gap caused by the crack. Cut into the cavity at least one inch in depth, making the bottom of the gap larger than the opening at the top. This will strengthen the adherence of the patch compound.
- For very large cracks, particularly those in a foundation where serious structural damage might be involved, it would be best to call a professional.