Had a job after a hailstorm where the homeowner had two layers of shingles—looked fine from the street, but once we started poking around, there was hidden rot in the decking. Insurance barely covered the tear-off because of the extra labor. I get why folks double up to save money, but man, it can bite you later if you’re not careful. If you’re in a spot with heavy storms or wild temperature swings, that second layer just doesn’t hold up as well in my experience. Sometimes it’s worth ripping it all off just for peace of mind.
Man, I see this all the time—folks think they’re saving a buck by just slapping another layer on, but it’s like putting a band-aid on a leaky pipe. Sure, it looks fine for a while, but once you peel back those layers, you never know what kind of science experiment is brewing underneath. I’ve crawled up into attics where the decking was so soft I felt like I was walking on a trampoline. Not exactly confidence-inspiring.
I get the appeal, though. Tear-offs are messy, noisy, and the bill isn’t exactly pocket change. But in places where you get wild weather swings—hail, heavy snow, or those 100-degree summers—two layers just don’t play nice together. The top layer can trap heat, and if there’s any moisture, it’s like a sauna up there. That’s when you start seeing rot, mold, and all sorts of stuff you’d rather not deal with.
Had a client last year who went the double-layer route about a decade ago. Looked fine from the curb, but when a storm finally did them in, insurance only covered the top layer. The extra labor to rip everything off came out of their pocket. They weren’t thrilled, to put it mildly.
If you’re in a mild climate and the first layer is in decent shape, maybe you can get away with it for a while. But if you’re anywhere with real weather, I’d say bite the bullet and do the full tear-off. It’s not fun, but at least you know what you’re working with. Plus, you get a chance to fix any hidden issues before they turn into wallet-draining nightmares.
Just my two cents. I’ve seen enough “roof lasagna” to last a lifetime.
I’ve dealt with a few “roof lasagna” situations myself and, honestly, every time I see multiple layers, I brace for some kind of surprise. In my experience, the extra weight can be a real issue—especially on older buildings that weren’t designed for it. Plus, like you said, insurance often only covers the top layer… which is a rude awakening when you’re already stressed from storm damage. I get why people want to avoid the mess and cost of a tear-off, but skipping that step can just kick the can down the road. At least with a full removal, you know what you’re dealing with under there—and your future self will probably thank you.
Had a job last winter where we found three layers stacked up—felt like opening a time capsule, except it was just damp plywood and a ton of rot. People really underestimate how heavy that gets over the years. I get why folks want to avoid the hassle and expense of a tear-off, but honestly, every shortcut seems to show up later as a bigger headache. Sometimes you peel back those shingles and realize the leaks have been hiding for ages... not fun trying to explain that to the homeowner.
Pulling up old shingles is like an archeology dig sometimes… you never know what you’ll find. Last summer, I helped on a house where we thought it was just a quick re-roof, but under the second layer, the plywood was basically mulch. I get wanting to skip the tear-off—it’s loud, messy, and costs more—but hiding problems doesn’t make them disappear. One thing I’m still trying to figure out: Is there ever a scenario where adding a layer is actually better? Or is it always just pushing off the inevitable?