Do-it-yourself insulating not likely to pay off

Q. My older house has no insulation in the walls. A contractor wanted $6,000 to pump in insulation through holes in outside walls, but the price doesn’t include repainting the house. Can I do the job myself with some kind of foam insulation?

A. Kits to insulate existing exterior walls with foam are available, but I can’t vouch for any of them and would hesitate to use them myself. One kit you might want to check out, however, is available at www.fomofoam.com.

I don’t think you would save much money, if any, by trying to do it yourself. A kit that will insulate 600 square feet of wall with one inch of foam costs about $700.

Properly insulating exterior walls can significantly improve comfort in a home and cut heating and cooling costs, but good coverage of the wall cavities is vital and can be difficult even for experienced contractors.

Some experts recommend using cellulose insulation, blown into the cavities through small holes, instead of foam. If you haven’t had a price on cellulose, you should get one. In fact, you should obtain at least three bids from different contractors before deciding.

You might also be eligible for a federal tax credit if the work is done this year; visit www.energystar.gov for details.

Also keep in mind that much of the heat loss through exterior walls goes through windows, doors and various other gaps and cracks. If you have drafty windows and doors, insulation won’t do much good; take care of those first by upgrading, weather-stripping and caulking.

Walls can also be insulated from the outside, using rigid-foam panels, when new siding is installed.

Finally, if it is the cost of repainting the entry holes that worries you most, I think it would be simpler to handle that part of the job yourself than to attempt do-it-yourself foam injection.

Q. When I moved into my house about six years ago, I noticed some water damage around the chimney in the attic. Since then, repeated efforts have been made to fix the chimney and stop the leak, including new roofing. Nothing has worked for long. What next?

A. I can only guess at the source of the leak, but it does sound as if the flashing around the chimney might be at fault. Even if the flashing looks sound, it only takes a small flaw to cause a leak.

I would have an experienced roofer check the sealing around the chimney and repair or replace the flashing if necessary.

Q. Why do I have mildew on just one side of my house? How do I get rid of it and keep it from spreading?

A. Mildew forms where there are moist, dark conditions. It often occurs on siding that faces north or where the siding is shaded by trees. If shading from trees appears to be a factor, try pruning them back so the siding gets more sun.

You can also get special cleaners that will remove mildew from most types of siding. Two well-known cleaners are Mildew Check and Jomax; they are sold at many home centers and paint stores. A homemade solution of one quart chlorine bleach to three quarts of water also is sometimes used.

Mildew cleaners are normally applied with a garden-type sprayer, allowed to work for five or 10 minutes, then are rinsed off with water from a hose.

You don’t say what type of siding you have, so be sure and read the directions and cautions before using any cleaner. Also test the cleaner on an inconspicuous part of the siding.