How to paint cracked masonry walls

Updated February 21, 2017

Many property owners like to apply a coat of paint over masonry walls to hide patched cracks and structural settling or just to provide a new fresh feel. Whether the masonry wall is indoors or out, you can paint it once you prepare the surface and choose a suitable paint. With the right tools and a little know-how, you’ll turn that old masonry wall into one you’ll be proud to tell your friends you painted.

Prepare the masonry wall by filling any existing cracks with premixed masonry mud. Make sure to clean the crack out first with your putty knife and sweep away any loose debris before wetting down the crack’s surface and pressing the masonry mud into the crack. The wetness keeps the masonry from drawing the moisture from the mud too quickly.

Remove existing light fixtures, outlet covers, switch covers and hydrants. If the wall features a permanent fixture, use masking tape to cover it securely. In addition, tape off all door trim and window trim to prevent paint errors.

Sand down surfaces with loose paint. You must remove all peeling paint or the new paint will come off with the old. If the masonry wall is made of textured blocks, consider renting a sandblaster to remove the old paint. Inside, use a wire brush to remove the loose bits.

Apply a coat of masonry primer to the wall as a base to hold the paint. Masonry primer acts like a layer of glue, increasing the paint’s adherence to the wall. If your wall has grease or rust stains, ask the paint shop attendant to add stain-blocker to the primer to keep the stains from bleeding through the new paint.

Spray, roll or brush the paint onto the masonry wall. This is your choice, depending upon the wall’s surface and the tools available. However, before using a paint sprayer, drape tarpaulins over nearby items and tape them securely in place to protect them from overspray. If you choose to roll the wall, select a thick quality roller to apply the paint evenly.

Repeat the painting process until you have a nice finished coat on the wall that completely covers the original wall. This usually means two coats for a brushed or rolled wall and three or more coats for a sprayed wall.

Replace outlet covers, fixtures and strip the masking tape from door and window trim when the paint is completely dry.


Spray masonry walls with very thin coats of paint to prevent runs. Just a hint of colour is all you need for each coat. Allow the wall to dry between subsequent coats.


Cover floors and other items you want to protect from paint drips.

Things You'll Need

  • Putty knife
  • Small hand broom
  • Premixed masonry mud
  • Water
  • Sandblaster or wire brush
  • Masking tape
  • Masonry primer
  • Masonry paint
  • Roller, brush or spray gun
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About the Author

Glenda Taylor is a contractor and a full-time writer specializing in construction writing. She also enjoys writing business and finance, food and drink and pet-related articles. Her education includes marketing and a bachelor's degree in journalism from the University of Kansas.