We recently moved into a house 3 months ago and I have noticed a foul odor from the basement. It is a very stale smell in the air and upon inspection of the walls, there is a thin layer of a soft "cocunut like" substance on the concrete type walls. Any ideas on what this is and how to treat it?

 

It sounds as if you have a poorly ventilated basement. Running fans will improve ventilation. Running a dehumidifier will bring humidity levels down. Areas affected by mold should be cleaned with bleach/water solution. Inspect basement for signs of moisture. Make sure gutters and downspouts are clear and are properly draining water away from the foundation. Make sure soil around the foundation is properly sloped and carrying water away from the foundation. Block or concrete basement walls can be sealed with a couple coats of masonry sealer to minimize moisture transpiring through walls. Concrete basement floors can be sealed with a couple coats of penetrating sealer. Inspect your basement during and after a few heavy rains to determine if there is moisture coming in somewhere.

Sometimes water penetrating concrete and block walls carry salts from the soil along with them. When the water evaporates the salt deposits are left behind. These are typically light colored, powdery deposits left on basement walls. Salt deposits can be effectively removed with white vinegar. Sulfate salts leave a white filamentous, moldy looking deposit. Sulfate salts eventually cause the concrete to deteriorate. The soil in most of North Dakota is high in sulfate salts.

The odor associated with mold/mildew is an earthy or musty smell. Mold may appear cottony, velvety, granular, or leathery. It can be white, yellow, gray, black, brown, or green. It often appears as a discoloration, staining, or fuzzy growth on basement walls and items in the home.