At What Point Does Shingle Roof Need Replacing?

QUESTION: The house I’m buying is about 20 years old. According to my home inspector, the roof shingles are worn out and should be replaced. The seller adamantly disagrees. He maintains that the roof has never leaked, even in the recent heavy rains, and is unwilling to replace shingles that still shed water. How can we resolve this stalemate?

ANSWER: You have encountered a head-on collision between the two most common techniques of evaluating roof serviceability.

One approach considers the overall physical condition of the material itself, while the other simply demands an answer to the question: “Does it leak?”

The first of these methods, the one employed by your home inspector, is the standard criterion employed by professional roofing contractors.

If the roofing is found to be damaged or decomposed, replacement is routinely recommended, regardless of whether there is evidence of leakage.

The “does it leak?” approach assumes that a roof that hasn’t leaked in the past is not likely to do so in the future. This flawed reasoning is often used in the hope of avoiding the cost of replacing a roof which, although gasping on its deathbed, has not yet died.

The essential question here is whether we should let an old weathered roof remain in place until its replacement is accompanied by water damage to the interior of the home. Should we simply ignore the warning signs of a failing roof, while exposing walls, ceilings and furniture to needless damage?

As to the question of replacing worn-out shingles, your home inspector’s recommendation should serve as a forewarning of impending roof failure.

In the absence of consensus between you and the seller, I recommend that you have the roof evaluated by a licensed roofing contractor for a final determination of the matter. A final solution will depend upon the true condition of the roof, the value of a home with deteriorated shingles and the motivation of the seller to complete the sale.

Settling Dispute Over High Water Pressure

Q: As a licensed engineer, I take exception to the findings of the inspector who just evaluated my home. According to the report, the water pressure in my plumbing system is 90 pounds per square inch, supposedly 10 pounds above the legal limit.

Based upon this finding, the buyer insists that I install a regulator. However, the inspector failed to notice the pressure relief valve in the main water line is rated at 150 pounds per square inch. This means that my plumbing system can withstand pressures well in excess of 90 pounds. How can I convince the buyer and the inspector that a regulator is not needed?

A: How can I convince you that a regulator is exactly what your plumbing system needs?

According to Section 1007 of the Uniform Plumbing Code: “Where local water pressure is in excess of 80 pounds per square inch, an approved type pressure regulator shall be installed and the pressure reduced to 80 pounds per square inch or less.”

Please note that this requirement is not conditional, nor does it provide any specific exceptions or alternate methods, such as pressure relief valves.

Standard plumbing fixtures are designed to withstand just so much pressure. At higher levels, they are prone to damage or leakage.

The connections in washing machines, for example, consist of rubber hoses clamped to plastic fittings; certainly not as substantial as solid pipe joints. If one of these fragile connections should break or disconnect because of excess pressure, the result could be extensive water damage to the interior of the home.

Adding a 150-pound pressure relief valve does not mitigate the need for code compliance, because it does not equip the in-house plumbing to tolerate higher pressure levels.

Your relief valve simply protects the system from pressures in excess of 150 pounds. But no protection is provided for pressures between 80 and 150 pounds. My advice is to follow the inspector’s recommendation. A pressure regulator is cheap insurance for the protection it provides.

Inspector Determines Earth-to-Wood Peril

Q: The wood deck behind my house is partially in contact with the soil, and the people who are buying my home insist that earth-to-wood contact should be eliminated.

I’ve explained to them that the deck can’t effect the building because the walls of the house are covered entirely with stucco. How can I make them understand that their concerns are unwarranted?

A: In all likelihood, the sale of your home will involve the services of a termite inspector. His job will be to determine whether earth-to-wood contact at the deck is likely to effect the house.

If the deck adjoins the building at stucco surfaces only, then damage to the structural framing is unlikely. However, be sure to consider whether the deck connects with any of the wood trim on the house. That could shed a different light on the matter.

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Do You Have a Question?

Got a question about any aspect of the home inspection? Send it to Barry Stone, Los Angeles Times, 540 Atascadero Road, Morro Bay, CA 93442.

Queries can also be sent via e-mail to: inspector@fix.net

All questions will be considered for use in “Ask the Inspector” but cannot be answered individually.