How to Waterproof Masonry With Liquid Silicone

Waterproofing masonry is essential to ensure your home lasts a long time. Moisture seeping through masonry walls and the foundation will weaken the structural integrity of a home. One option is a liquid silicone paint coating, better known as elastomeric coating. Once you apply it, the exterior of your house will be moisture-proof, and interior moisture will be able to escape without damaging the coating. With the right tools and directions you can quickly waterproof a masonry wall.

Connect the garden hose to the pressure washer and turn on the water. Use the pressure washer to clean the entire exterior surface that you want to waterproof. Remove all dust and debris to ensure the elastomeric coating sticks. Let the surface dry for at least 48 hours.

Cut the masking paper to size using the scissors. Cover anything you do not want to paint, including windows and doors, with the masking paper. Attach it with painter's tape.

Cover the cracks with the elastomeric patch compound, using a spatula. Let the patch dry for at least eight hours.

Put the elastomeric paint in the paint sprayer following the sprayer manufacturer's directions. Spray the masonry surface evenly. Let the first coat dry for 48 hours. Spray a second coat. Let it dry for at least 72 hours before painting it with latex paint.


New masonry surfaces should not be sealed with elastomeric paint until after 30 days.

Things You'll Need

  • Pressure washer
  • Garden hose
  • Painter's tape
  • Masking paper
  • Scissors
  • Elastomeric patch compound
  • Spatula
  • Paint sprayer
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About the Author

Louis Gutierrez began writing in 2010 for various websites, specializing in real estate, construction and electronics. He has over 10 years experience running and operating various successful businesses in these fields and holds a Bachelor of Arts in business administration, graduating magna cum laude from Florida International University.