Code compliance vs. common sense
Q: We were ready to close escrow on our home when the buyers' home inspector stirred up trouble over the roof repairs. The house is about 45 years old and has two layers of asphalt shingle roofing. According to the roofing contractor, the building code allows a third layer to be applied, but the home inspector says the roof structure is sagging and should not be loaded with the weight of additional shingles. Removing the old material will add about $8,000 to the cost of the job and seems to us to be a needless expense. As far as we're concerned, the roof structure is strong enough to support another layer of shingles. If a third layer would be detrimental, it wouldn't be allowed by code. Don't you agree?
A: You're right, I don't agree. Here's why.
The building code allows two layers of shingle roofing for some roofs and three layers for others, depending on the pitch of the roof. However, these standards can be superseded by local building departments. Therefore, you should check with your municipal building official to see how their standards apply to your roof. You should also be aware that code requirements are not intended to be followed blindly. The building code defines itself as a "minimum standard." Therefore, codes should be applied to each situation in the light of common sense. Here is how that would apply to your situation.
When the code recommends a maximum of three roof layers, the underlying assumption is that the roof structure is framed and reinforced in compliance with other pertinent building codes, enabling support of three layers. If your roof is currently sagging under the weight of only two shingle layers, it is reasonable to assume there is a lack of integrity in the rafter framing.
Disagreements sometimes arise regarding interpretations of the building code. A prudent way to resolve these differences is to consider the intent of the code. With regard to numbers of roof layers, the purpose of the code is to protect the framing from structural damage. If sagging is evident, there is reason to believe a significant problem exists. Therefore, the situation at hand should take precedence over the strict letter of the code.
An alternate approach to stripping off the old shingles would be to reinforce the roof framing inside the attic, but the cost of doing this would most likely exceed the removal of the old shingles. My advice, therefore, is to remove the old shingles, as the home inspector advised. Although this will entail additional cost, it will protect you from potential liability problems after the close of escrow. And just to be on the safe side, it would be a good idea to have the rafter framing checked to determine exactly why sagging has occurred. If a framing problem is discovered after the close of escrow, that could also be a liability problem.
• To write to Barry Stone, visit him on the web at www.housedetective.com, or write AMG, 1776 Jami Lee Court, Suite 218, San Luis Obispo, CA 94301.
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