If underlayments had a race: which one would cross the finish line last?

Felt’s always been the weak link in my experience, especially on steeper roofs where the sun just bakes it. I’ve seen synthetic hang on for months after a project stalled - one job, we had a freak hailstorm and the synthetic barely looked scuffed, while the old felt on the shed next door turned to mush. Peel-and-stick is a beast too, but it’s not cheap. I’m still waiting to see cork in the wild... seems like a gamble in our climate. Anyone else notice synthetic getting slick when wet, though? Makes inspections interesting.

Synthetic definitely wins the endurance game in my book, but yeah, it’s like an ice rink when there’s morning dew or after a rain. I nearly took a slide off my garage last fall - lesson learned, sneakers don’t cut it. I’m curious if anyone’s tried those “walkable” synthetics? Supposedly grippier, but I haven’t seen much difference. Felt just can’t handle the sun here (Texas), but at least you don’t need cleats to walk on it.

I get what you’re saying about synthetics being slick - especially first thing in the morning or after a storm. I’ve tried a few of those “walkable” synthetics, and honestly, the grip is only marginally better. If you’re on a steep pitch, it’s still dicey. I’ve seen some crews use those foam-soled boots, which help a bit, but nothing’s perfect.

One thing I’d toss out there: not all synthetics are created equal. Some of the heavier-weight ones (like the 60+ mil stuff) have a bit more texture, but they’re pricier and not always stocked locally. I’ve also noticed that some brands get almost gummy in the Texas heat, which helps with traction but can be a pain to roll out.

Felt definitely wins for walkability, but like you said, it just doesn’t last under the sun here. I’ve seen it start curling up in less than a week in August. For me, it’s a trade-off - if I know the roof’s going to be exposed for more than a couple days, I’ll put up with the slippery synthetics just for the peace of mind that they’ll hold up until the shingles go on.

I get what you’re saying about synthetics being slick - especially first thing in the morning or after a storm. I’ve tried a few of those “walkable” synthetics, and honestly, the grip is on...

That’s a good point about the heavier synthetics getting gummy in the heat - seen that myself after a hailstorm last spring. We had a section of synthetic (I think it was 50 mil, not the thickest) exposed for almost three weeks while insurance sorted things out. It held up fine, but walking on it after a rain was like stepping onto a slip-n-slide. The crew ended up laying down some old towels just to get traction.

Felt’s walkability is nice, but I’ve watched it basically disintegrate after a couple of storms, especially if there’s any pooling water. One time, a section literally tore off in the wind before we could get shingles down. Peel-and-stick is a whole different animal - pricey, but I’ve seen it survive hail and baking sun for months. Only downside is, once it’s down, good luck getting it back up without a fight.

If I had to bet on which one would limp across the finish line last, felt’s probably out first, then lighter synthetics. Peel-and-stick or the thickest synthetics seem to hang on the longest, at least in Texas weather.

I’ve had similar issues with felt just not holding up, especially when storms roll through before you can get shingles down. Last year, I tried a lighter synthetic (maybe 30 mil?) on a detached garage, and it was a mixed bag. It didn’t tear like felt, but after a week of Texas sun and a couple of downpours, it started curling at the edges. Not a total fail, but I wouldn’t trust it for more than a couple weeks exposed.

Peel-and-stick is a beast, though. I put it on a porch roof as a stopgap, and it sat there for almost two months - hail, 100-degree days, you name it. Only thing is, once it’s baked on, it’s basically permanent. If you ever need to redo decking or fix a mistake, it’s a pain to get off.

If I had to rank them for “race to the finish,” I’d say felt is out first, then the thinner synthetics, then the heavy synthetics, and peel-and-stick is the last one standing. But yeah, walkability is a whole other story... I’ve nearly wiped out more than once on those slick synthetics after a rain.

I get the appeal of peel-and-stick for durability, but honestly, I’m not convinced it’s always worth the hassle. When I was redoing my shed roof, I went with a heavy synthetic (I think it was 60 mil?) and left it exposed for almost three weeks. It handled some pretty nasty wind and rain - no curling or tearing, and it was way easier to move around on than the thinner stuff. Didn’t have the “permanent glue” problem either, which was a relief when I realized I’d misaligned a row and had to pull it up.

I get that peel-and-stick is basically bulletproof once it’s down, but if you’re not 100% sure about your decking or layout, it feels risky. Plus, the cost was way higher at my local supplier. Maybe it’s different in other climates, but for me, the heavy synthetics seem like a good middle ground. Walkability is still sketchy after rain, though - almost ate it stepping off a ladder last fall. Anyone else feel like the “grip” claims on the packaging are just marketing?

Walkability is still sketchy after rain, though - almost ate it stepping off a ladder last fall. Anyone else feel like the “grip” claims on the packaging are just marketing?

Had a similar moment last spring - misjudged a slick spot on my neighbor’s roof and nearly slid right off. I know the synthetics are supposed to be “grippy,” but in my experience, nothing beats a good pair of sticky-soled shoes and taking it slow. I do see your point about peel-and-stick being risky if you’re not 100% on your layout, but I’ve found it’s been a lifesaver on my old farmhouse where leaks were a constant battle. Once it’s down, I don’t have to worry about water sneaking in at the seams. Price is steep, yeah, but for tricky valleys or low-slope spots, I’ll pay the extra just for peace of mind.

I hear you on the peace of mind with peel-and-stick, especially where water likes to sneak in. On my last job, the synthetic felt looked grippy enough - until a quick drizzle turned it into an ice rink. I still remember sliding halfway down before catching myself on a vent. Maybe it’s just me, but I’d trade some “walkability” for better long-term leak protection any day. Curious if anyone’s used any of the newer recycled-content underlayments? I’m trying to go greener, but haven’t seen much real-world feedback yet.

Peel-and-stick definitely wins for leak protection, but yeah, you’re not kidding about the “skating rink” effect with some synthetics when they’re wet. I’ve seen more than one guy do the unintentional slide - never pretty. As for the recycled-content stuff, I’ve only come across it a couple times on new builds. It looked promising, but honestly, I’m still a little skeptical about how it’ll hold up after a few freeze-thaw cycles. Maybe it’s just old habits, but I’d rather trust something with a track record than be the guinea pig. Still, if it actually performs and keeps junk out of landfills, I’m all for it.

As for the recycled-content stuff, I’ve only come across it a couple times on new builds. It looked promising, but honestly, I’m still a little skeptical about how it’ll hold up after a few freeze-thaw cycles.

I’ve been wondering the same thing about those recycled underlayments. My place is in the Midwest, so we see everything from ice storms to 90-degree summers. Anyone have actual long-term experience with them? I keep hearing they’re “green,” but if they crack or curl in two winters, that’s not much help. I’m leaning toward synthetic just for the peace of mind, even if it means dealing with the slip-and-slide effect during install.

I get the hesitation - recycled underlayments sound great on paper, but the Midwest climate is brutal on anything that isn’t up to par. I’ve seen a couple of projects where recycled-fiber underlayment was used, and after three winters, there was some minor curling at the edges, but nothing catastrophic. Still, it’s not as bulletproof as the higher-end synthetics, especially with all the freeze-thaw cycles and sudden temperature swings we get.

The “green” angle is important, but if the material fails early, it’s not really sustainable in the long run. Synthetics are slippery during install, no denying that, but the durability is hard to beat. Some of the newer recycled options are getting better - manufacturers are tweaking blends and adding UV stabilizers - but I’d still call them a work in progress for harsher climates.

If you’re dead set on minimizing environmental impact, maybe look for a hybrid: recycled content with a synthetic top layer. Otherwise, I’d probably stick with synthetic for now, just based on real-world performance.

That’s interesting about the recycled stuff curling up after just a few winters. I’ve seen similar things with some of the early “green” underlayments - not total failures, but definitely not holding up like synthetics. Has anyone actually pulled up shingles after, say, 10+ years to see what’s going on underneath? Wondering if the recycled blends break down more or if it’s just the edges that suffer. Climate’s a real test out here...

I’ve actually wondered about this too, especially since I’m in the “learning as I go” camp with my first house. My place is only about 8 years old, so I haven’t had to pull up shingles yet, but I did peek under a loose one last fall. The underlayment (I think it’s some kind of recycled felt blend?) looked a little rough around the edges - literally. Not falling apart, but definitely not as crisp as the stuff in the middle.

I’m in a spot where we get wild temperature swings - hot summers, freezing winters. I can’t help but think that’s gotta be hard on anything that’s not fully synthetic. Has anyone seen if the center sections hold up better than the edges, or is it just a matter of time before the whole thing starts to go? Also, does it make a difference if you’ve got a steeper roof vs. something closer to flat? I keep hearing mixed things about how much slope matters for underlayment lifespan.

I’ve managed a few properties with roofs in all sorts of conditions, and honestly, the edges always seem to go first - especially on the lower slopes. Had a place with a 10-year-old felt underlayment, and the center was still hanging in there, but the eaves and valleys were rough. I think the slope matters more than people say. Flatter roofs just seem to cook in the sun and hold moisture longer, which really beats up the underlayment over time.

I hear you on the edges going first - my last house had a low-slope section over the porch, and the felt there looked like it’d been through a war zone after about 8 years. The main roof (steeper pitch) was fine, but those flatter spots just never dried out after a rain. I tried patching with some peel-and-stick, but it was more of a temporary fix than anything.

If you’re watching your budget like I am, it’s tempting to just stick with felt, but I’ve been eyeing those synthetic underlayments. They’re pricier up front, but folks say they hold up better in spots that stay damp or get hammered by sun. Has anyone here actually seen synthetic outlast felt on a low-slope roof? I’m wondering if the extra cost is worth it, or if it’s just marketing hype.

Also, curious if anyone’s had luck improving edge life with drip edge or ice & water shield? I’ve heard mixed things, but maybe there’s a trick to getting a few more years out of those trouble spots.

- I get the hype around synthetics, but honestly, I’m not totally sold for low-slope spots. Had a buddy swap to synthetic on his porch roof - looked great at first, but after five years, still had moisture issues at the seams.
- For me, ice & water shield along the edge did more than any underlayment swap. It’s pricier, but less hassle than redoing felt every few years.
- Drip edge helps, but only if you install it right and keep gutters clear. Otherwise, water just finds a new way in.
- If you’re in a spot with freeze/thaw cycles, I’d say focus on sealing those edges tight - underlayment alone won’t save you.
- Sometimes old-school felt is fine if you’re on a budget, just gotta stay on top of maintenance.

Just my two cents... not sure there’s a magic bullet for those flat spots.

Sometimes old-school felt is fine if you’re on a budget, just gotta stay on top of maintenance.

I get the appeal of felt for saving money, but in my experience, it’s the first to fail if you get any pooling or ice damming. On my garage (low slope, Midwest winters), I tried 30# felt - lasted maybe four years before I had to patch leaks. Switched to a basic synthetic after that and haven’t looked back. Not perfect, but it’s held up better than I expected, especially with a tight drip edge and regular gutter cleaning. For me, the extra upfront cost paid off in fewer repairs down the line.

- Totally agree, felt is cheap up front but I’ve had to patch it more than I’d like.
- Midwest winters here too - ice dams are brutal. My shed roof with 15# felt lasted maybe three years before water found its way in.
- Switched to synthetic on the house last time. Cost more, but I haven’t had to mess with it since.
- Still, if you’re re-roofing every few years anyway (like on a chicken coop or something), felt might make sense?
- For anything you want to last, synthetic seems worth the extra bucks.
- Curious if anyone’s tried those peel-and-stick membranes - are they overkill for regular homes?

Peel-and-stick membranes are kind of a game changer if you’re dealing with ice dams or a low-slope roof. I used one under metal panels on my garage, and it’s been bone dry through some really nasty freeze-thaw cycles. For a regular pitched roof, it might be overkill everywhere, but I’d definitely run it along the eaves and valleys. It’s pricier, but the peace of mind during those Midwest freeze-ups is hard to beat. Anyone else notice they’re a pain to remove if you ever need to do repairs, though? That’s my only gripe.