Basement Cinder Block Salt Repair

Leaching salt is a common feature of masonry walls in damp environments

When water seeps into and through basement cinder block, it dissolves salt and other minerals, which then leach out to the surface of the block, causing a white discoloration. This "efflorescence," which also can occur on outdoor surfaces, as well as basement floors, is unsightly but easily treated and usually poses no structural danger to the block or the wall.

Things You'll Need

• Dropcloth or large sheet
• Wire brush
• Water
• Muriatic acid for etching block surfaces
• Basement sealer

Instructions

1. Move any and all furniture, objects and rugs away from the wall. If it is carpeted, cover the floor with a dropcloth or large sheet you use for home projects.

2. Remove loose debris from the wall with a wire brush.

3. Soak the wall with clean water. This will reduce the porousness of the wall and keep the cleaning solution closer to the surface on which you will be working.

4. Apply muriatic acid, diluted at 1:12 (one part acid to 12 parts water) concentration, to the wall. Wait for an hour, then reapply the solution. Two or more reapplications are more effective than a single heavy coat.

5. Wash the wall with clean water. This dissolves and removes the cleaning solution, which if allowed to remain on the surface will further degrade the cinder block.

6. Prime the wall and apply a basement sealer to the cinder block.

7. Install a dehumidifier in your basement and run it for an hour or two every day to reduce the latent humidity in the room. This will help lower the rate of moisture condensation on the surface of the wall, which leads to efflorescence when the moisture eventually evaporates.

Tips & Warnings

• Sandblasting is an effective method of removing salt and efflorescence, but it will degrade the wall and cause it to become even more porous to moisture.

• Install a fan to exchange warm air for the cooler air in your basement. This will slow down the condensation that causes efflorescence.

• If the problem occurs in warm-weather months, it might be as a result of increased seasonal humidity and not a moisture leak. Keep doors and windows closed at this time of year to help reduce the intake of humid air.

• A continuing problem with efflorescence at any time of the year means you have a moisture problem. You will have to isolate the leak and/or repair any cracks in the masonry, which is wicking the water in from the outside. .

References

• Basement Questions: Efflorescence
• The B-Dry System: Efflorescence

Resources

• GardenWeb Forum: Efflorescence in Basement