Question - We had a new church built two years ago, and we still don't have a concrete basement floor in it. The basement walls are always damp.

Sometimes there are beads of water and mildew on them. There is also a real musty smell at times. I don't think we have water coming in from the outside. I think we have a serious sweating problem. What do you think?

Answer - It sounds like a lot of moisture is entering the basement from the dirt floor. If your church cannot afford to cover the dirt floor with a concrete slab, then it should at least cover the floor with polyethylene sheets.

Even when the dirt floor feels dry to the touch, a considerable amount of water still evaporates into the atmosphere of the basement because of the capillary rise of ground moisture. According to the Small Homes Council at the University of Illinois, the soil under a 1,000-square-foot house can release as much as 18 gallons of water per day through evaporation.

Even with a concrete slab or vapor barrier covering the floor area, it may be necessary to use a dehumidifier to help control the amount of moisture.

Question - I have a concrete driveway and I'm confused as to whether I need to use a sealer. I've heard both pro and con on this subject. What's your opinion?

Answer - Driveway sealants are a controversial topic in many areas of the country, primarily because they are often used by traveling bunco artists to bilk unsuspecting homeowners out of thousands of dollars. In many cases, a sealer simply isn't needed, no matter how clever or persuasive the sales pitch.

But mass hysteria aside, driveway sealants do serve a purpose in some situations. They are often required when new concrete is poured in late autumn. In this instance, a sealant keeps water from entering the slab and popping the surface with the first deep freeze.

Ironically, the more years a driveway goes without a sealant, the less it is likely to need one. The reason is that normal surface grime from dirt, car tires and, yes, oil spills help seal the concrete. If yours is a relatively new drive, or if you've noticed unusual surface degradation, then a sealant is probably in order.

Question - We have hot water baseboard heat and we get a constant knocking at both ends of the baseboard units when the heat is coming up and also when it's going down. Our house has upper and lower levels and a two-level heating system. Do you know what's causing this noise and how to eliminate it?

Answer - All piping materials expand and contract with temperature changes. A 50-foot length of copper pipe, any diameter, will expand in length more than one-half inch when the water inside is raised from 70 degrees to 170 degrees (typical for a baseboard heater). This expansion can strain joints and cause leaks.

The noise is probably caused by the heat distribution pipes or connecting fins rubbing on their support brackets as the pipes expand when the heat is coming up and as they contract when the heat is going down.

This noise can usually be eliminated or reduced by inserting foam rubber pads between the baseboard support brackets and the connector fins or distribution pipe, whichever is being supported. When inserting the pads, gently lift the heating pipes or fins. If you apply too much pressure, you can strain pipe joints and possibly crack them.