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PROPER MIX OF INSULATION, VENTILATION CAN SOLVE CONDENSATION PROBLEM

SHARE PROPER MIX OF INSULATION, VENTILATION CAN SOLVE CONDENSATION PROBLEM

Question - We have a problem with water staining where the ceiling meets the walls at the front and back of the home. The attic is insulated with 6 inches of Fiberglas roll-type insulation plus about 4 inches of loose cellulose on top of that. There is a ridge vent in the attic, but we had the two gable vents covered when new vinyl siding and new windows were installed. The overhangs are well-ventilated. We had a furnace humidifier which we turned off, and that seems to help a little.

The bathroom is just outside the room with the biggest problem. We installed a bigger fan in the bathroom, and it is always turned on when we take showers. The house is about 1,400 square feet with a full basement. I would appreciate any help you can give us concerning the water problems.

Answer - The moisture levels inside your home are probably the same now as they were before you remodeled. The big difference is the new windows.

The older, single-paned windows allowed the moist air to condense on the cold glass and acted as a dehumidifier for each room.

The newer windows are insulated so now the moist air, which is warmer and rises to the ceiling, collects on the coldest spot in the room, namely the wall-to-ceiling joint on an outside wall. It is difficult to properly insulate this area and still maintain the required air gap between the insulation and the roof's decking.

Make sure your new exhaust fan vents all the way to the overhangs and is well-insulated. You don't want the moist bathroom air to condense inside the attic.

Assuming the walls of the home are insulated, start in the attic area, making sure the area over the outside wall is well-insulated.

Use insulation baffles, purchased from lumber companies or insulation dealers, to keep the insulation away from the roof's decking.

If you are unable to reach this area try the following:

Cut two pieces of 6-inch lightweight PVC sewer pipe to a length of 2 feet. Next, slice the pipe in half, lengthwise. You now have two pieces 2 feet long by 3 inches wide. Using binders twine, attach a 2-foot piece of 6-inch-thick-by-16-inch-wide unfaced fiberglass insulation to the two pipes, which are laid side by side on the insulation.

Using an adjustable painter's pole, slide the insulation to the outside wall area with the pipe side up. This will insulate the area and the pipes provide the necessary air gap.

Do the same thing for each cavity area. It's a lot of work but should pay off in the long run.

Question - Six months ago I scraped the peeling paint off the ceiling over my shower stall, applied a stainblocker and sealer, then painted it. Now it is again getting mildew spots where moisture beads up on it and does not dry.

There is an overhang at the shower door that is between the shower ceiling and the bathroom ceiling. This helps trap moisture inside the shower. Should I consider moving the bathroom exhaust fan directly over the shower?

Answer - There are paints that are mildew resistant, or you could have the ceiling covered with a ceramic tile.

I do not recommend placing an electric fan over a shower area. The fan would rust rapidly; the moisture might condense inside the vent pipe from the fan or you could receive a serious shock from touching the fan housing.

Question - I live in a condominium, and all along the front concrete walk there is a gap between the walk and the building, and rain water drains from the walk into the gap. There is a French drain on the other side of the walk, but it's not very efficient during a heavy rain.

I have noticed water damage on the inside wall of the basement - paint is peeled off and the wall is crumbly. The association has tried to caulk the gap, but this has never lasted long nor has it solved the problem. Do you know of any way this problem could be solved, or will it hurt to just let it go?

Answer - Run-off water that is allowed to build up next to a foundation can cause serious structural damage to the building. The basement could start to leak or the wall could cave in.

French drains are efficient if the area is kept clear of debris and the drains are large enough to handle the rains. Another choice is a yard drain which is a plastic grate connected to a buried drainage system to handle excess water from a yard, patio or driveway.