How to Patch a Concrete Floor
When patching a floor, make your work stick by using a bonding adhesive. Here's what to do:
Materials and Tools:
1. Wearing gloves, knee pads, safety glasses and dust mask, use the awl to probe the area and remove any loose debris. If you just patched over all the debris, the patch wouldn't have a firm surface to grip and would probably fail.
2. Use a shop vacuum to clean up the area.
3. Scrub the area with a wire brush.
4. Use a paintbrush to spread the bonding agent evenly over the affected area. Make sure the surface is covered and all the tiny pores and holes are filled. Let the adhesive dry for about an hour.
5. Pour some cement into the mixing tub, create a depression for the water in the center and fold the dry material into the wet with the trowel. Use large gravel or aggregate if necessary to match the texture of your floor. Add more water if needed to reach the desired consistency.
6. Fill the hole with the concrete and pack it in tightly by hand. Always wear gloves when working with concrete, as the chemicals in the mix may irritate your skin.
7. You may need a "dustier" mix to fill smaller holes. If so, use a small sifter to remove chunks of aggregate from the mix, leaving you with a lighter mix, and use a tuck-pointed trowel for filling holes.
8. To level the concrete, start in the middle of the patch and use both hands to pull a straight board across the surface. Use a sliding motion and work from one side to the other.
9. Allow the concrete two weeks to cure, and then prime and paint to match the rest of the floor.