The thing is, a lot of folks don’t realize how much extra weight those extra shingles add, especially on older rafters. I’ve been up in attics where you can see the sag plain as day.
That’s what gets me too—how do you really know if your rafters can handle it, unless you’re crawling around up there? I’ve always wondered if there’s a rule of thumb for when a second layer is “safe” or if it’s just a gamble every time. Does anyone actually get a structural engineer to check, or is it just a “looks fine” kind of thing most of the time?
Also, from a green perspective, isn’t tearing off the old shingles better in the long run? I mean, yeah, it’s more landfill, but at least you can see what’s going on underneath and maybe even upgrade insulation while you’re at it. Or am I overthinking that part? Just seems like layering is a shortcut that could bite you later, but maybe I’m being too cautious.
I get what you’re saying, but honestly, I’ve seen plenty of houses with two layers that are still standing just fine—no saggy rafters or anything wild. Not saying it’s always the best move, but sometimes ripping everything off feels like overkill, especially if the first layer is in decent shape. Plus, in my area, nobody’s calling a structural engineer unless the roof looks like it’s about to cave in. As for the green angle, yeah, more landfill stinks, but hauling all those old shingles off isn’t exactly carbon-neutral either. Guess it’s one of those “pick your poison” deals...
Guess it’s one of those “pick your poison” deals...
That’s exactly how it feels. I keep asking myself, is adding a second layer really that risky, or is it just one of those things roofers say to upsell a full tear-off? I mean, my neighbor’s house has had two layers for at least 15 years—no leaks, no sagging, and we get some pretty heavy snow up here in Michigan. But then again, I’ve heard stories about hidden rot under the old shingles that nobody finds until it’s too late. Is that just bad luck or poor inspection?
The landfill thing bugs me too. On one hand, yeah, less waste if you just go over the old stuff. On the other, what happens when someone finally does have to rip off both layers? Twice the mess down the line? And does anyone actually notice a difference in insulation or energy bills with two layers? Or is that just marketing fluff?
I keep going back and forth. Every time I think I’ve decided, I read something else and start doubting again...
Here’s the deal: second layers aren’t always a scam, but they’re not risk-free either. If your first layer is solid—no soft spots, curling, or moss—you can sometimes get away with it. But you can’t see rot or bad decking without a tear-off, and that’s where people get burned. As for insulation, two layers don’t really help much. And yeah, when it’s time to replace, double the mess and cost. I’ve seen both work out fine, but I’ve also seen hidden damage get missed for years... It’s really about the condition of what’s underneath.
