I remember helping my uncle out with his roof last summer—he had two layers of old shingles, and the attic was always roasting. He skipped ridge vents when he did the second layer years ago, thinking it’d be fine with just a couple more box vents. Fast forward, and now there’s weird discoloration on one side and the plywood underneath is starting to warp. Kinda makes me wonder if ripping everything off and starting fresh is worth the hassle, even though it’s way more work upfront. Those “dead spots” are real, especially on older houses.
Kinda makes me wonder if ripping everything off and starting fresh is worth the hassle, even though it’s way more work upfront.
- Not always a must to rip it all off. If the decking’s still solid (poke around with a screwdriver), sometimes you can just fix the venting and go over one layer.
- Two layers isn’t ideal, but I’ve seen roofs last ages with proper airflow.
- Ridge vents do more than folks think—box vents alone leave hot pockets, like you saw.
- Full tearoffs are pricey and messy... but yeah, warped plywood is a bad sign. Just saying, sometimes you can get away with less if you catch it early.
- Gotta push back a bit on the “just go over one layer” idea.
—that only works if you’re totally sure there’s zero hidden water damage. I’ve had roofs look fine on top, but once we pulled shingles, found rot spreading in spots no one expected. Layering saved money short term but cost way more later when we had to replace decking and insulation.“sometimes you can just fix the venting and go over one layer”
- If you’re managing multiple properties, chasing leaks under two layers is a total headache. Insurance claims get trickier too.
- Tearoff is a pain, yeah, but sometimes it’s the cleaner fix long run—even if it stings upfront. Just my two cents from dealing with a few surprises...
I get where you’re coming from, but is a full tearoff always the answer? I’ve had a couple roofs where we did go over one layer—after checking for soft spots and moisture—and those held up fine for years. Not saying it’s risk-free, but sometimes budgets just don’t stretch to a full tearoff, especially with older rentals.
—true, but if you’re careful about inspections, is it always that bad? Maybe depends on the age and condition more than a blanket rule.“chasing leaks under two layers is a total headache”
I get the argument for going over one layer, especially if you’re dealing with an old rental and the numbers just don’t add up for a full tearoff. I’ve done it myself—checked for rot, made sure everything was dry, and slapped a new layer on. It held up fine for about eight years, which honestly was longer than I expected.
But here’s where I get nervous: you can’t see what you can’t see. Even if it looks solid, there’s always that nagging doubt about hidden moisture or soft decking. And yeah, tracking down leaks under two layers is a pain. Had that happen once after a bad storm—took forever to find the source because water traveled between layers.
I guess it comes down to risk tolerance and how long you want the roof to last. If it’s your own house and you plan to stay put, I’d lean toward tearing off. For a short-term rental or if money’s tight, maybe layering makes sense... just know you’re rolling the dice a bit more. Climate matters too—up north with ice dams, I’d be extra cautious.