How to Cover-Up Cinder Block Grout Lines

Cinder block walls are sturdy and functional, but you may consider the dull, gray appearance unattractive. You can paint a cinder block wall to add color, but you are still left with the pores in the concrete and the grout lines that make the wall obviously a cinder, or concrete, block construction. Applying a coating of surface bonding cement to the wall not only seals the wall but covers the obvious pores and grout lines, giving you a smooth wall surface.

Surface bonding cement
Wheelbarrow
Sprayer
Trowel

Instructions

- 1
  Clean the wall, removing any grease, dirt or oil from the surface.
- 2
  Mix the surface bonding cement with water in a wheelbarrow or large mixing tub, using 1 ½ gallons of water for a 50-pound bag. Adjust measurements according to manufacturer’s instructions. Mix only the quantity that you can apply in one hour.
- 3
  Spray the wall with water. The wall should be wet but not dripping with water.
- 4
  Dip a wet trowel into the mixture. Apply it to the wall, beginning at the top and working downward. Spread the mixture up and outward using firm pressure. Apply a thin coat of approximately 1/8-inch. Continue to add the bonding cement to the wall, overlapping the edges.
- 5
  Clean the trowel with water. Run the clean, wet trowel over the finished surface to smooth it out.
- 6
  Spray the finished surface with a mist of water one or two times during the first day to facilitate the curing process
- 7
  Wash all tools in water as soon as you finish the job to prevent the cement from hardening and ruining your equipment.

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