Which finish is best used when subject to regular dampness?

• A. Putty finish
• B. Sand finish
• C. Portland Cement Plaster Finish
• D. Keene's cement finish

Answer: (C)

When a surface is regularly damp, you want a finish that blocks moisture and holds up under wet conditions. Portland Cement Plaster Finish fits that need because cement-based plaster cures to a dense, hard barrier that resists water penetration and damp-related damage. It’s hydraulic, meaning it gains strength and durability through exposure to moisture, which helps prevent cracking and deterioration in damp environments.

Putty finish is soft and moisture-absorbent, making it unsuitable for damp conditions. A sand finish adds texture but remains porous and less protective against ongoing moisture. Keene’s cement finish is lime-based and breathable, which is good for moisture management in some contexts, but it doesn’t provide the same level of water resistance as cement plaster in regular dampness. So the cement plaster option offers the best protection against ongoing moisture exposure.