Whatcom County Home Inspection (King of the House): Detecting A Multi-layer Roof

Actually, this title is a bit like the old question: "Who is buried in Grant's tomb?" The way you detect a multi-layer roof is by looking. That can, however, be harder than you would expect. The photo below is the simple way, just tweak the shingles a bit and you see another color below. The best place to look is at the eaves or at the gable ends. Sometimes there will be a metal drip edge flashing put over an old roof and that can make it harder to be sure what is below. On the other hand, I did an inspection this morning and the roof was covered with ice and the material so frozen and non-pliable that I was afraid that gently pulling on it would tear a shingle. While most home inspectors like to see only a single layer of composition shingles on a roof, many roofers will put on two layers which usually leaves a number of old metal flashings, sometimes rusted, below the new roof. If there are already two layers, that pretty well guarantees that the next roof will first require a tear-off. If you think about it a concern with multi-layer roofs is weight. If you have ever carried a bundle of comp shingles up a ladder to the roof, you know this is no issue to take lightly -- pun intended. This is a heavy topic.

Thanks for looking.

Steven L. Smith

Bellingham WA home inspector

www.kingofthehouse.com