How to Fix a Dent in Cinder Block

Shallow Dents

• 1

  Put on a dust mask and a pair of safety glasses.

• 2

  Clean out the inside surfaces of the dent. Use a wire brush to round off any sharp or jagged edges inside the dent. Blow into the dent to remove the dust.

• 3

  Chisel the area at the bottom of the dent so that it is slightly wider than the top of the dent. The dent should have a slight taper from bottom to top. The extra space at the bottom of the dent will give the epoxy a place in which to expand and properly set.

• 4

  Fill the dent with concrete epoxy. Wipe away any excess epoxy with a rag. Allow to dry.

• 5

  Paint the cinder block to match the color of the wall if you desire.

Deeper Dents

• 6

  Remove any paint around the dent with a wire brush. Scrape out the inside of the dent with the wire brush to remove any jagged edges or sharp pieces.

• 7

  Dampen a clean rag or towel with water. Lightly dab the area inside and around the dent with the wet cloth.

• 8

  Dip a paintbrush into a can of concrete bonder. Brush on a coat of concrete bonder inside the dent. Allow the bonder to dry for several minutes. Wait until the bonder becomes tacky or sticky before proceeding to the next step.

• 9

  Cut a piece of chicken wire so that it will fit inside the middle of the dent. The chicken wire will provide the patching cement with anchor to which to adhere. You can also use a small piece of hardware cloth in place of chicken wire if you so choose.

• 10

  Apply a layer of patching cement to the dent with a masonry trowel or the edge of a putty knife. Fill in the center of the dent first, and work your way out towards the edges. Do not leave any gaps between the packing cement and the edges of the cinder block. Wipe away any excess patching cement with a rag.

• 11

  Allow the patching cement to dry. Wait a minimum of two to three weeks before repainting over the packing cement. Paint will not stick well to the cement until all of the lime leaches out of it, which can take a few weeks.