How to Plaster a Cement Block Wall

Cement or concrete walls are usually pale gray in color and uninviting to the eye. You can paint the walls with latex paint, but you'll still see the rough texture of the cement behind the paint. In addition, cement tends to soak up paint over time and you will find yourself constantly painting the walls to keep them looking fresh. To avoid this and to cover up those cold gray walls, you can plaster over the cement. This will give you a smooth wall for painting.

Mortar
Trowel
Plaster
Sanding pole
Flashlight

Instructions

- 1
  Fill in any cracks in the wall with an acrylic-based silicone sealer. Cracks are an entry point for water and will eventually break through the plaster. Acrylic-based silicone caulk will seal the cracks and prevent moisture from reaching the plaster.
- 2
  Apply a skin coat of mortar to the wall with a trowel. Mix the mortar to the specification of the manufacturer. Use a ready-mix mortar, which is cost effective and only requires water for mixing the powder. Apply the mortar from the top of the wall down and flatten it out with the trowel. Apply the mortar in a 1/8-inch coat just to seal the brick. Allow 48 hours drying time.
- 3
  Apply a ¼-inch coat of plaster to the surface of the wall with your trowel. Apply the surface as flat as possible. Allow 48 hours drying time.
- 4
  Sand the surface of the wall with a pole sander to remove any imperfections such as lines left by the trowel. Shine a flashlight across the face of the wall to expose any humps or dips.

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Plaster Walls Vs. Drywall

Wall Repairs