How to Finish a Cinder Block Wall

Clean the Wall

• 1

  Clean the surface of your cinder block wall with soapy water if your cinder block wall is new. Scrub the wall with a wire brush to remove lose mortar. For new walls, this is the only cleaning you will need.

• 2

  Remove any efflorescence that has formed on older walls. Efflorescence is a powdery white substance that can form on the surface of concrete and cinder block walls. It is caused by water on the other side of the block. Remove the efflorescence with an acidic masonry cleaner and a stiff wire brush.

• 3

  Scrape old paint from the wall to prepare it for priming. In some cases, especially with outdoor walls, it may be easier to pressure wash the wall than hand-scrape the entire surface.

Painting

• 4

  Apply a masonry primer to your clean concrete. The primer will seal the concrete and provide a good, stable surface for paint adhesion.

• 5

  Caulk expansion joints in the cinder block wall with a non-sagging polyethylene caulking after priming the wall. Caulk around windows and doors with an elastomeric caulking.

• 6

  Paint your cinder block wall with a gloss or semi-gloss acrylic paint.