How to Tank Damp Walls

While damp walls can affect the appearance of paint and wallpaper, the biggest danger is mold.
Tanking damp walls prevents mold development.Tanking damp walls prevents mold development.
There are over 50 types known to cause sickness in humans such as infections, sinusitis and asthma. To help ensure your walls are dry, you can tank them. This is a form of waterproofing, and when done correctly, ensures moisture does not invade your walls.

Step 1

Dry off damp walls with microfiber towels. If necessary, set up large fans to blow against the walls for at least one day. Once dry, carefully remove debris, old plaster, paint and loose pieces using 40- to 60-grit sandpaper.

Step 2

Mix salt neutralizer in the proper amount of water determined by the product instructions, and spray on the wall with a spray bottle. The neutralizer removes traces of salt, which enhances the sticking action of the tank slurry. Allow it to dry.

Step 3

Mix the cement slurry according to the manufacturer's directions. Add a replastering additive to it. The amount required is based on the amount of slurry you’re mixing. Stir all the ingredients together with a wooden spoon or stick until the slurry is thick and smooth.

Step 4

Apply the cement slurry in horizontal strokes to the wall with a 3-inch wide paintbrush. Allow it to dry. Apply a second coat in a vertical motion. Once dry, you have a tanked wall, which can then be plastered or painted.

Things You Will Need

  • Microfiber towels
  • Large fans, optional
  • 40- to 60-grit sandpaper
  • Salt neutralizer
  • Water
  • Spray bottle
  • Cement slurry
  • Replastering additive
  • Wooden spoon or stick
  • 3-inch wide paintbrush

About the Author

Jonathan McLelland has been a professional writer since 2005. He has worked as a story writer and editor for the international sitcom, “Completing Kaden,” as well as a proposal writer for various production companies. McLelland studied communication and theater at St. Louis Community College.