by Barry Stone, Certified Building Inspector

Dear Barry,

The house I'm buying is twenty years old. According to my home inspector, the roof shingles are worn out and should be replaced. The seller adamantly disagrees. He says the roof has never leaked, and he's unwilling to replace shingles that still shed water. How can we resolve this stalemate? Randy S.

Dear Randy,

You have encountered a head-on collision between the two most common techniques for evaluating a roof. One approach considers the physical condition of the material itself, while the other demands a black and white answer to the pragmatic question: "Does it leak?"

The first method, the one employed by your home inspector, is the standard criterion applied by most professional roofing contractors. If the roofing is damaged or decomposed, replacement is routinely recommended, regardless of whether there is evidence of leakage.

The alternate standard, the "does-it-leak" approach, could be fairly regarded as a form of wishful thinking. It assumes that a roof which hasn't leaked in the past is not likely to do so in the future. This flawed reasoning reflects the desperate hope of avoiding costly roof replacement; of relying old shingles which, although gasping their final breath, have not yet fully expired.

The essential question is whether an old weathered roof should remain in place until its replacement is accompanied by water damage within the home. Should we simply ignore the warning signs of a failing roof, while exposing walls, ceilings, and furniture to needless damage? If home inspectors and roofing contractors were to adopt this standard, we might also expect Auto mechanics to forego brake repairs as long as a car is still able to stop. Or perhaps a dentist should refrain from filling cavities until the patient is racked with chronic toothache.

Your home inspector's recommendation should serve as a forewarning of impending roof failure. In the absence of consensus between you and the seller, the roof should be evaluated by a licensed roofing contractor for a conclusive bottom line determination. A final solution should be based upon the true condition of the roof, the affect of a deteriorated roof on the value of the property, and the motivation of the seller to complete the sale. But remember, the seller is not obligated to replace the roof, even if replacement is warranted: That would depend upon the terms of the purchase contract.

Dear Barry,

On cold mornings, I notice moisture dripping from the skylight above my bathroom. I've tried sealant to prevent leakage and have installed a piece of Plexiglas on the roof above the skylight. But still the dripping continues. How can I eliminate this problem? Ervin L.

Dear Ervin,

Sealant and Plexiglas are not likely to solve your problem, because the dripping is more likely due to interior condensation than exterior leakage. High humidity often occurs in a bathroom, especially when a shower is used. When outside temperatures chill the surface of the skylight, airborne moisture can condense into droplets.

A practical solution would be increased ventilation. Bathrooms are required to have openable windows or exhaust fans, but sometimes both are needed to eliminate excessive humidity. Once you vent the moist air to the exterior of the building, condensation should cease to be a problem.

Distributed by Access Media Group. To contact Barry please visit his website at http://www.housedetective

http://www.housedetective.com.