The first step in repairing fine cracks in concrete is to properly prepare the surface. A clean, solid surface is required for the repair material to adhere to the permanently damaged area. When working with cement-based products, always wear safety glasses and gloves.
Clean the surface of the damaged area by removing dirt, oil or grease or any part of the concrete that is in poor condition or peeling off before applying the repair material. Using a concrete and asphalt cleaner, scrub and clean the surface of the area to be repaired with a stiff-bristled brush. Thoroughly rinse the repair area after cleaning.
To repair fine cracks in concrete
Repair fine cracks in small areas where the surface is cracked or damaged using a product such as QUIKRETE Vinyl Concrete Patcher. Vinyl Concrete Patcher is ideal for repairing fine cracks in concrete and can be applied in cracks from ¼ inch to the thickness of the edge of a pen.
Mix the primer by adding approximately 10 ounces of water to 5 pounds of material, pouring the dry mix into the water. (The more water is added during the mixing process, the weaker the adhesion and compression capacity will be). Mix the concrete primer for 3-5 minutes using a steel trowel. Once a lump-free consistency is achieved, let the mixture sit without moving for approximately 5 minutes.
Before applying the mixture, stir the material once more. You can add additional water in small amounts to achieve a putty consistency. Wet the area to be repaired with enough water to saturate the surface. Remove any stagnant water residue. (Never add water once the material has started to dry.)
Apply the concrete primer as a layer using a steel trowel. You will need to apply the first coat by pressing the trowel firmly into the area you are repairing. Smooth the surface of the patch so that it is level with the surrounding concrete. Avoid adding water to the surface of the patch. Protect the area you are repairing from 24-hour pedestrian traffic and vehicular traffic for at least 3 days.
For small non-structural repairs
For small non-structural concrete repairs, i.e. cosmetic concrete repairs, use a product such as QUIKRETE Concrete Patching Compound. Concrete Patching Compound Refiner contains a ready-to-use, premixed acrylic latex formula that adjusts to the color and texture of the surrounding concrete. It should only be applied when the temperature is between 50 and 90 degrees Fahrenheit.
Mix concrete cure compound using a trowel or spatula before applying to a clean, dry surface.
Spread the concrete primer and create a texture that resembles the texture of the surrounding concrete. For patches or cracks more than ¼ inch thick, the compound should be applied in multiple coats, allowing each coat to dry before applying the next. For a smooth finish, wet the palette. The patch will begin to scab over in 20 to 40 minutes and will fully harden in 1 to 2 hours, depending on temperature, humidity, and patching work.
What you will need to repair fine cracks in concrete
- Vinyl concrete primer or concrete primer
- Concrete and asphalt cleaner
- Chisel and hammer
- Wire bristle brush
- Steel trowel
- Scrub brush
- Measuring bowl
- Gloves and goggles