Slab floor may be culprit in dealing with mildew

Q. I note dampness, mildew, and an offensive odor in my house which sits on a concrete slab. Does the slab cause moisture? What do you suggest I do to rid the house of the problem? Would a dehumidifier work? Joyce B. Jeffreys Gravette, Ark.

A. A dehumidifer might help some but I do not believe it would be altogether satisfactory. You may have to look further for an answer.

Concrete slabs do not create moisture but they may well brood it. If the slab were poured on-grade without a waterproofing membrane between it and the ground, unwanted dampness may indeed be present in the slab.

Determine first the source of the moisture, if possible. In other words, is the moisture in the slab or under it, in the attic from a hidden leaky pipe, from a gutter or downspout, or where? Then counter the moisture at its source by whatever means needed after you find its origin.

My guess is that the culprit is the damp concrete slab. If this is correct, try to intercept the moisture outside the house foundation. You may need to install footing drains to run ground water to ''daylight'' instead of letting it build up under the floor.

We were once consulted on a similar problem in California where mildew was in the carpet pad. A funguslike odor permeated the furni ture, carpet, drapes, linen, and clothing.

We removed the carpeting and had it cleaned. The smelly, moldy pad was then thrown away. Furniture and clothing had to be cleaned to remove the offensive odor.

Then we applied a proven waterproofing agent to the concrete floor. The product we used was Sealwall which is made by a company of the same name in Eastlake, Ohio. The phone number is: (216) 951-3445. You also can look for an equal.

It worked and the slab moisture never returned, nor did the mold and odor. The cleaned carpeting was laid over a new pad.

You may need to approach your problem in a similar way.