Mottling
Deposition of salts on masonry surfaces. Crusty white salt deposits, leached from mortar or masonry as water passes through it.
Causes:
- Appear on new brick, plaster or cement as they dry.
- Improper curing.
- Failure to adequately prepare surface by removing all previous efflorescence.
- Excess moisture escaping through the exterior masonry walls from the inside.
- Alkaline bricks
Solution:
- The source of moisture must be repaired before any paint preparation.
- If excess moisture is the cause, eliminate the source, sealing any cracks in the masonry with sand and cement.
- If moist air is originating inside the building, consider installing vents or exhaust fans, especially in the kitchen, bathroom and laundry areas.
- Remove the efflorescence and all other loose materials with a wire brush, power brush or power washer; then thoroughly rinse the surface.
- Apply a coat of Wall Sealer and allow it to dry completely; then apply a coat of top quality exterior paint.