A beautiful three-story dark red brick, limestone, and concrete structure that went through an extensive renovation recently, still had high relative humidity readings. The basement walls were refinished with concrete plaster and freshly painted, greatly enhancing the aesthetic appearance of the interior. However, the limestone and concrete foundation was trapping excessive moisture and salt, which always finds a way out. This would have destroyed the expensive renovation efforts. Now the salts and moisture are being released and gently drawn out, so the new plaster will now last many years. Maintenance costs will be reduced as well.