Home & Garden

Roofing warranties negated when shingles are improperly nailed

Q: I called a roofer because I had a leak in my replaced roof. The roof is only two years old but the roofer told me the shingles were not nailed correctly and that my warranty would not be any good. He gave me a price to replace all the shingles and to get a new warranty. Is this something that happens often? Should I replace a 2 year old roof?

A: There are a lot of things that can cause a new, or mostly new, roof to leak.

Improper flashings can cause leaks. They are found at roof penetrations such as roof vents, a chimney, plumbing vents or anything that penetrates the new shingles.

Leaks are especially hard to find where a lower roofline, such as a garage roof, meets an upper vertical wall, such as a second story wall. The water comes off the roof during a heavy rain and is trapped against the vertical wall. A well-placed piece of adhesive-backed rubber sheeting along the lower roof and up the wall will keep water out of the home.

Your estimator told you the shingles were not nailed correctly. This can happen when the installer is in a hurry. Each nail — there are four per shingle — must be placed on the asphalt adhesive tab just above the watermark and the nail has to be straight, not installed at an angle. A straight nail applies the full force of the nail head evenly on the asphalt tab. A nail head set at an angle will cut through the tab damaging the shingle and it may even come loose. During a windy rainstorm, water can penetrate under the loose shingle to the damaged opening where a leak begins to form.

The roofer is right — the warranty from the manufacturer is no longer valid if the shingles have been nailed improperly. If you only have a small leak, consider having the shingles repaired rather than replaced. Loose or improperly nailed shingles can be repaired and resealed at a reduced cost and still give you years of protection from the elements, but there will not be a manufacturer’s warranty.

C. Dwight Barnett is a certified master inspector with the American Society of Home Inspectors. Write him at C. Dwight Barnett, Evansville Courier & Press, P.O. Box 268, Evansville, Ind. 47702 or e-mail him at d.Barnett@insightbb.com.

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