I love the people who say its “unacceptable” to add a roof over an existing roof. It makes me laugh. If only you could provide a logical reason why it’s unacceptable. Too heavy? Really, well why is it that at 200 lbs I can stand on a square foot of my roof but two or three pounds of shingles in a square foot is too heavy? Go take a couple engineering classes. Moisture will get caught between the old and new shingles? Really, how is it any different than a layer of felt directly on board? It isn’t. If you install the new roof when the old one is dry it will be just fine. You can’t see damaged wood underneath? You can find damaged wood by walking the roof. If you don’t detect it by walking it then it isn’t that bad and installing the new roof correctly will stop any further wood damage. Those of you that want to tear off go ahead, but just keep your dumb opinions to yourself as far as roof overs, you don’t know what your talking about. It’s much easier, cheaper and just as good as a tear off. Maybe better, after all you have two roofs instead of one.
I don’t know what you did for a living but I do know you know how to install a shingle roof at expert level ,I’m a retired journeyman roofer/Waterproofer and I would not have done 1 thing different if I was installing that roof ,nor could I have done a better job and I attended a 4 year trade school to become a Master roofer/Waterproofer and spent nearly 40 years installing roofs ,anybody looking for a tutorial showing how to reroof their own home can’t get a better demonstration of how to recover a roof and have it meet code ,good job buddy .
+Edward Vp please explain exactly why installing a lay over that’s installed over a nice flat existing roof that’s not plagued by nail pops is a bad idea ,I’ve held a Journeyman card in Roofing & Waterproofing over 30 years and can’t see any reason why this man’s roof is not the PERFECT example of how to install a lay over that will outlast the roof underneath ,a lay over turns a 2 ply shingle roof into a 4 ply roofing system .
So what do you do when your new roof fails in half the time because the old shingles underneath continue to crumble and cause lumps under yours. Then you will have to pay extra for the double layer tear off and new shingles. Or is that too just be the cost of the next person who owns the home?