Dear Ken: Last summer we purchased a new furnace, humidifier and air filter system. They said dust in the house would be cut down a lot, but we've noticed no difference. What's up? - Heather
Answer: What kind of furnace filters do you use? Make sure you install the corrugated paper style - not the cheap mesh type. Nonetheless, they may have oversold you a bit. Dust can settle on furniture and other surfaces regardless of your furnace's efforts. Even the best vacuum will spritz dust particles back out through the bag surfaces; that's why central, piped systems do so much better. Also, lots of wind-blown dust creeps in around windows and doors, so try plugging the little "weep holes" in your exterior window frames with a small chuck of sponge.
Another big source of incoming dust and dirt is that gap at the bottom of the siding where it meets the foundation. You can spray in some expanding foam, or simply stuff chunks of Fiberglass insulation into the crack with a screwdriver.
Dear Ken: I have a crawl space and have noticed moisture coming up from the ground and a lot of bluish mold and white crystals. What can I do? - Marty
Answer: You probably need better ventilation down there. I assume you have several crawl-space vents in the exterior walls. They have been required for years, but they mostly get overlooked and are considered energy wasters. They are vital to moderate the humidity down there, however, and to protect the wood on the underside of your house from deterioration. Plus they are usually part of the combustion air scheme for your furnace, water heater, fireplaces and clothes dryer.
Set a small fan in the most northerly opening for a week or two, blowing out the vent; plug it into a timer so it runs for two or three hours every morning. That will help lower the moisture level in the crawl space, and it will discourage fungus and crystal growth. Rather than disinfect the soil, scrape off the top layer of foreign material and discard it. Once the soil is moderately dry, cover it with a layer of 6-mil, black plastic sheeting.
Of course, you'll need to tackle any outside sources of this excess dampness. Make sure there are no dripping faucets, move sprinkler heads away, divert the downspouts and switch to dry-scape landscaping near the house.
All these changes will make the area cooler than usual. So you'll probably want to insulate the "ceiling" of the crawl space - the underside of the floor. Use some plain 6-inch batts with no paper facing. Why no paper? Relative humidity levels differ between the crawl space and the rooms above. The unfaced insulation will allow equilibrium between the two areas without trapping mold-producing moisture under the floor.
Dear Ken: The concrete driveway at my new home seems to be hollow underneath. Spaces are on the sides, and when I hit it with a hammer it sounds like a drum. The builder wants to add dirt. Is that the best idea? - Tom
Answer: Chances are, your driveway was built over a utility ditch, such as the sewer or water line, and that disturbed soil has settled. Adding dirt at the sides is OK, but it doesn't do much for the interior of the subsidence, where the real loading occurs. A better way is to inject a concrete slurry (soupy sand and cement) underneath with a high pressure injector. It's a form of mud jacking, which we usually use to lift a slab back into position. In your case, instead of raising something, we're simply pushing down on the dirt.
Dear Ken: I am putting new cedar boards on the south side of my house. The contractor suggests staining both sides first. What do you think? - Jack
Answer: I don't think it will make any difference. Stain is not a seal coat, like paint, so you're not adding any moisture barrier protection to the boards. I'd save the money for something else.
Moon is a home inspector in the Pikes Peak region. His radio show airs at 9 a.m. Saturdays on KRDO, FM 105.5 and AM 1240. Visitaroundthehouse.com