Q. We live in a small three-bedroom home in a subdivision outside of Fort Wayne. The house is a two-story split-level with what I think is about a 4/12 roof pitch. The house is 40 years old and is showing some wear to the roof. The kids have moved out, so my wife and I are thinking of selling and moving into something that is one level. I have had two roofing contractors look at my roof. One says I can roof over the existing and the other said the only way he would do it would be to tear down all the sheeting before installing new shingles. By the way, my current roof is a 3-in-1 style shingle and the existing roof is laying very smooth. The first guy told me this. Should I consider roofing over? — Gerry of Allen County
A. Any old contractors out there like me remember T lock shingles? They were typically used for higher pitch roofs like old downtown houses and single-layer roof shingle. We used these a lot years ago to do roof overs.
I don’t even think you can get them anymore. These days with the new roof shingle styles and architectural style shingles, we always tear off the original roof down to the sheeting and install new flashings, ice and water shield, felt paper and aluminum drip edging before installing new shingles. The main reason is warranty.
Without attaching shingles to a clean subsurface you void the manufacturer’s warranties. The new roof must lay flat to perform properly long term.
You probably have an ideal situation to install a roof over, if you roof is simple, meaning you don’t have lots of flashings or roof planes to deal with and these flashings are in excellent condition.
With having a 3-in-1 shingle now and it’s laying nice, straight and flat, you now can lay a new 3-in-1 shingle right over the old shingle. Line it up with the existing shingle, same row line and all. They will lay flat right in line with the existing old shingle. You will need to reseal the flashings and roof boots, but it will continue to lay flat and have good long-term performance.