I’ve seen a few installs where the peel-and-stick underlayment made a real difference, especially on older roofs with brittle shingles. It’s not a cure-all, but it does help minimize leaks if the shingles don’t seal back down well. I’d say it’s more useful as a backup than a primary defense, though. On one inspection, I found that even with the extra layer, some water still got in around the fasteners because the shingles were just too far gone. If you’re already seeing granule loss and exposed matting, patching or waiting for a re-roof might be the safer bet.
I’d say it’s more useful as a backup than a primary defense, though.
Couldn’t agree more. I slapped peel-and-stick underlayment under my last attic vent install, thinking it’d be a solid safety net. It definitely helped, but once those old shingles start curling and losing granules, water finds its way in no matter what you do. At that point, patching feels like putting duct tape on a leaky boat. If your roof’s showing its age, sometimes biting the bullet and planning for a full re-roof is just less hassle in the long run.
I hear you on the patching vs. replacing debate. I tried to stretch my old three-tab shingles for a couple more years by doing spot repairs and using that underlayment tape around the new vent. It worked... until it didn’t. Once the shingles started cracking and the granules were mostly in the gutters, water just found new ways in. I get why people want to avoid a full re-roof (I sure did—quotes were brutal), but at some point, it’s just money down the drain trying to keep the old stuff going.
Did you look into overlaying new shingles over the old ones? I was tempted since it’s cheaper up front, but I kept hearing mixed things about whether it actually lasts or just causes more problems later. Curious if anyone’s had luck with that, or if it’s just a band-aid too. For me, once I saw daylight through the attic boards, I figured it was time to stop patching and start saving for the big job.
Did you look into overlaying new shingles over the old ones? I was tempted since it’s cheaper up front, but I kept hearing mixed things about whether it actually lasts or just causes more problems later.
Tried the overlay route on my dad’s old ranch back in ‘09. Looked fine for a while, but the extra weight and trapped heat did a number on the decking. Ended up with warped boards and even more leaks after one bad hail storm. Sometimes that “cheap up front” turns into double the headache. Did you run into any warranty issues with your new install, or did the contractor even mention that? Some won’t touch an overlay job at all around here.
Yeah, the warranty thing is a biggie. Most of the roofers I’ve dealt with flat-out refuse to warranty an overlay—something about not knowing what’s lurking under those old shingles. I had one guy tell me it’s like putting a band-aid on a leaky pipe... looks fine until it doesn’t. Plus, in our climate, that extra layer just cooks the attic even more. Did your contractor mention anything about ventilation or how the fan install might mess with shingle warranties? Some of them get real picky about new penetrations through layered roofs.
