Handy home improvement tips
Q: We are buying a house with a slate roof, but some of the slates have what looks like black tar on them. Is that just some sort of discoloration, or is there a problem?
A: There’s a problem. Slate roofs will last about 100 years, but they do fall victim to the stresses of freezing and thawing, and can be cracked by falling branches during windstorms. The tar is a cheap, temporary fix to stop a leak coming from a cracked slate. If there are a lot of tar-covered slates, your roof probably is due for replacement.
Slate is probably the most expensive roofing material, and shingle manufacturers have come up with new products that look like it yet don’t compromise the architectural integrity of a house. If you have the money, slate is the way to go. If you don’t, check out the alternatives.
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Q: We have had a mold assessment that indicates non-toxic mold, but we are being advised to have professional remediation done at a cost estimated at $11,000. Since the mold is not of the toxic variety, is this really necessary? Some contractors also are telling us that we might have asbestos to deal with. Our house is 40 years old. We are more confused than ever.
A: Does the $11,000 cost include finding what’s causing the mold? It’s fine, I guess, to clean up mold, but if the source of the problem isn’t addressed, you’ll be spending money to clean it up every couple of years.
There’s no practical way to eliminate all mold and mold spores in the indoor environment; the way to control indoor mold growth is to control moisture. You’ll need to find the source of the moisture. Once you take care of it, odds are you won’t have a mold problem.
It’s not impossible that a 40-year-old house would have some asbestos, probably in textured paint used for popcorn ceilings or in floor tiles, or naturally occurring in vermiculite used as attic insulation. If it is not disturbed, deteriorating or damaged, asbestos is not much of a problem because fibers aren’t being released into the air.
If the mold-remediation contractor is going to disturb the asbestos, then you will have to have it removed by a licensed asbestos-abatement contractor before the remodeling project begins.
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Q: Do you use duct tape to seal ducts?
A: If you mean the household kind of duct tape, no. Heat hardens the adhesive in most household duct tapes. Over time, the tape loses its stickiness and the duct leaks again.
It looks pretty ugly, but most energy-efficiency experts use duct mastic. It has the consistency of mashed potatoes and cures to form a durable seal. Mastic comes in one-gallon buckets or, for sealing certain joints, in caulk-gun tubes.
Seal gaps around ducts with spray foam where they penetrate the floor or ceiling. In addition, ducts in an attic or crawl space should be insulated. If your ducts are uninsulated or poorly insulated, seal them first, then add insulation to keep the air in your ducts at its desired temperature as it moves through the system. Use duct-insulation material rated at least R-6.
Why? At current fuel prices, heat is the last thing you want to waste.