How to repair small concrete crack
1. Clean the Floor
Before using any concrete filler, make sure there’s no oil or dirt still on the floor. If there is, use a cleaner that cuts grease. This will help the filler bond to the cement.
2. Brush and Vacuum
Once you’ve keyed the crack, it’s important to clean up and get rid of dust and debris. Use a whisk broom then vacuum the crack thoroughly.
3. Spread Concrete Patch
To use the concrete filler, cut the nozzle off the bottle and slowly fill the cracks (image 1). If you’re using mixed concrete patch, mix according to the manufacturer’s direction and then trowel the patch into the crack (image 2). Check the cracks in a few minutes to see whether the filler has settled. You may have to add some more if it doesn’t look tight. Use a trowel to smooth out the cracks