Q: There is obviously something wrong with the wood around my porch, which my neighbor says is dry rot. What is that?

A: Dry rot is a generic term for a variety of wood fungi, which cause mildew, mold, staining and decaying in wood. In order for dry rot to develop, it requires a certain combination of moisture and heat and air. If the conditions are right, dry rot can occur before you can visually detect it, within four to six months.

The reason that it becomes a problem is that infected wood loses its structural integrity. Once detected, this damaged wood must be totally replaced, or the fungi, which are living organisms, will continue to spread and cause more damage. Dry rot can also attract pests such as termites, which will only compound the problem. Repairing dry rot cannot be postponed, because the damage will only increase, as will the cost of repair.

Q: Where is dry rot most likely to develop?

A: Dry rot can be found both inside and outside your home. The most common areas inside are the bathroom, under kitchen sinks, in window sills around sweating windows, in thresholds near sliding glass doors, in the attic from a leaky roof and in the walls, particularly in homes which have a concrete slab foundation.

Outside, dry rot can occur in wood siding, eaves of the roof, decks and other wooden landscape structures and around the windows.

Q: Is there anything I can do to prevent dry rot?

A: In the bathroom: Shower doors should be caulked and sealed properly to prevent leaking. Plumbing fixtures should also be caulked. Replace cracked or broken tiles or missing grout in the shower and bath areas. Look for signs of leaking or water staining around the base of the toilet. Check the baseboard or moldings for signs of mildew. Also keep an eye on walls which adjoin the bathroom -- mildew can grow on a closet wall adjacent to the bathroom, for example.

Throughout the house: Check for moisture under any of the sinks. Inspect the attic for roof leaks and moisture from improperly vented dryers or exhaust fans. If you have a slab foundation, check walls behind the furniture for mildew. If you have a raised foundation, check under the house for excessive moisture. Periodically, run a test by turning on the water in the shower or tub and look under the house for leaks.

Outdoors: Check the placement of your sprinkler heads to make sure there is no direct spray hitting your house. Make sure shrubs and plants growing next to the house don't touch the siding because they can hold moisture. Check around hose bibs to detect leaks. Check the roof eaves; the wood will be soft or may show a white powdery residue. It may be caused by improperly installed roof flashing, a roof leak, or you may need gutters. Around decks, look for earth-to wood contact next to posts or any wood members and under potted plants. It's a good idea to treat decks with a wood preservative.

Q: What do I do if I discover dry rot?

A: Call a licensed general contractor who specializes in dry rot repair or a pest control company to assess the damage and recommend solutions. A licensed pest control operator should do the initial inspection, then get three competitive bids from licensed general contractors to do the repairs. Make sure that the person you hire is properly licensed and has experience in working with dry rot.

by Kathy Maynard, reprinted courtesy of HomeAdvisor.com