finally found an underlayment that lasts - what's your experience?

At least the ice and water shield in the valleys has saved me from a few angry calls after storms... worth every penny there.

I’m with you on that - ice and water shield is like insurance for my peace of mind. I tried felt once and it turned into a soggy mess after a surprise rain. Still not sure if synthetics are really “new and improved” or just new and expensive, but I’ll admit, not having to redo things is nice. Anyone else notice some of them feel almost too slippery to walk on?

I get what you mean about synthetics - some of them really do feel slick, especially on a steeper pitch. I had a crew refuse to walk on one brand last year because they said it was like ice under their boots. That wasn’t great for keeping the job moving, so I’ve been more careful about what I order since then. The trade-off is they hold up way better if you get caught with a sudden downpour mid-job, which happens more than I’d like around here.

On the cost side, I’m still torn. They’re pricier up front but I haven’t had to deal with any callbacks for leaks or wrinkling like I did with felt - especially when it sat exposed for a few days. That’s worth something in my book, especially since tenants don’t care if it’s “just the underlayment” when water’s coming through the ceiling.

Curious if anyone’s actually seen long-term issues with synthetics breaking down? Most of mine have only been on roofs 5-7 years now so it’s hard to say if they’ll last as long as advertised. Also, has anyone tried those “walkable” versions some brands are pushing? Wondering if that’s marketing or if they really make much difference in practice.

I manage a mix of asphalt shingle and low-slope roofs, mostly in an area that gets pretty wild freeze-thaw cycles and some big wind gusts. The ice and water shield in valleys has saved me more than once from major headaches - no question there. But for the rest of the roof, I’m still figuring out where to draw the line between cost and durability.

Anyone seen insurance companies push back on synthetic underlayments or are they pretty much industry standard now? Just trying to avoid any surprises when it comes time for claims after a storm...

- Totally get where you’re coming from on the slick synthetics - had a couple of close calls myself, especially when there’s morning dew.
- The upfront cost stings, but I’ve noticed fewer headaches with leaks and callbacks too. That peace of mind is worth a lot, especially if you’re juggling multiple properties.
- Haven’t seen any breakdowns yet, even after some wild weather swings. Most of mine are 6 years in and still look solid when I peek under repairs.
- Tried one “walkable” brand last fall - definitely less slippery, but not miracle stuff. Still gotta watch your step, but it helped on steeper pitches.
- Insurance hasn’t batted an eye here (Midwest), but I always keep the product docs handy just in case.
- Sounds like you’re making smart calls balancing cost and durability. It’s not easy, but you’re ahead of the curve compared to folks still using old-school felt everywhere.

- Totally get where you’re coming from on the slick synthetics - had a couple of close calls myself, especially when there’s morning dew. - The upfront cost stings, but I’ve noticed fewer hea...

That “walkable” brand you mentioned - tried it myself on a 7/12 pitch, and yeah, it’s better but still not foolproof. I do like the peace of mind with synthetics, even if the price hurts up front. For me, the real win is not having to worry every time we get a heavy rain or big temp swing. Old felt just didn’t cut it here (Northeast) with all the freeze/thaw cycles. No issues with insurance either, but I keep all my install docs just in case.

For me, the real win is not having to worry every time we get a heavy rain or big temp swing.

Totally agree with this. I used to stress every time the forecast called for a downpour - old felt just didn’t hold up in our New England winters. The synthetic stuff isn’t perfect (I’ve slipped a couple times too), but it’s been way more reliable. Pricey, yeah, but I’d rather pay once than patch leaks every spring. Keeping install docs is smart... insurance can be picky.

Yeah, I get the appeal of not stressing every time it rains. I’m still a bit skeptical about how long the synthetic stuff will actually last, but so far it’s holding up better than the old felt ever did. My main gripe was the price too, but honestly, dealing with leaks is way more expensive (and stressful). I kept all my paperwork just in case - heard too many stories about insurance nitpicking over “improper install” or whatever. Still crossing my fingers it holds up through a few more winters...

I hear you on the price - synthetic underlayment isn’t cheap, but man, I’ve seen way too many folks try to save a buck with felt and end up with water stains or worse after a big storm. Had a neighbor who thought he’d outsmart the system… two years later, he’s got buckets in the living room and a fight with his insurance company. Paperwork is gold, honestly. As for longevity, I’ve ripped up some synthetic after 8-10 years and it still looked decent. Not perfect, but definitely better than felt ever did in our climate. Crossing my fingers for both of us this winter...

As for longevity, I’ve ripped up some synthetic after 8-10 years and it still looked decent. Not perfect, but definitely better than felt ever did in our climate.

That’s good to hear. I’m in the same boat - paid more for synthetic last year and kinda held my breath about whether it was worth it. Our winters are brutal and I’ve seen felt just disintegrate after a couple seasons. Curious if anyone’s had issues with synthetic getting slippery during install? My roofer mentioned it was a pain on steeper pitches. Wondering if that’s just him or a common thing.

I had the same concern about the slipperiness, actually. When we did our roof last fall, the crew used synthetic underlayment (I think it was GAF Deck-Armor or something similar) and the foreman mentioned it was a bit like walking on a plastic tarp, especially early in the morning with dew. Our house has a pretty steep pitch - nothing crazy, but enough that I wouldn’t want to be up there myself. They ended up wearing those spiked shoe covers for grip, which looked kind of ridiculous but seemed to help.

One thing I noticed: after a couple days in the sun, the synthetic seemed to “settle” and wasn’t as slick. But during install, especially if it was damp or frosty, it was definitely more treacherous than felt. The guys said they preferred felt for traction but liked synthetic for everything else - weight, durability, and how it didn’t tear if you looked at it funny.

I’ll say, after seeing how the old felt just crumbled in my hands when we tore off the old shingles (it was only 7 years old), I’m glad we went with synthetic. Our winters are rough too - lots of freeze/thaw and wind. The peace of mind is worth a little extra hassle during install, at least from my perspective as someone who’s not actually up there doing the work.

Funny enough, I had a neighbor who tried to DIY his shed roof with synthetic and nearly slid off. He ended up putting down some old towels just to get enough grip to finish nailing it down. Not exactly OSHA-approved, but it worked for him.

Long story short, I think your roofer’s not alone in finding it slippery, but most seem to agree it’s a tradeoff worth making for longevity. Just glad I’m not the one balancing up there...

I’ll say, after seeing how the old felt just crumbled in my hands when we tore off the old shingles (it was only 7 years old), I’m glad we went with synthetic. Our winters are rough too - lots ...

That’s wild about the towels - definitely not OSHA-approved but hey, whatever works in a pinch, right? I’ve had a couple crews complain about synthetic being slick, especially in the mornings. Makes me wonder, is there a brand out there that’s actually less slippery or is it just the nature of the beast? Also, curious if anyone’s seen issues with synthetic in super hot climates - does it ever get too brittle or shrink? I’ve only dealt with it in the Midwest, so not sure how it holds up in, say, Arizona.

I hear you on the slick factor - synthetic underlayment can be like ice, especially with a little dew or frost. I’ve tried a few brands (Titanium, GAF, and some off-brand stuff) and honestly, they’re all a bit slippery, but the ones with more of a textured surface seem to help a little. Still, nothing’s perfect. We started using those grippy shoe covers for the crew, which made a difference.

As for hot climates, I did a job down in Texas last summer and noticed the synthetic held up fine during install, but after sitting exposed for a couple weeks in 100+ temps, it got kind of wavy - not brittle exactly, but definitely not as tight as when we rolled it out. Didn’t see any actual shrinkage, but I’d be careful leaving it uncovered too long in that kind of heat.

Felt just doesn’t cut it anymore for me either. Too many callbacks from leaks or it just falling apart if there’s any delay with shingles. Synthetic isn’t perfect, but it’s been way more reliable overall.

As for hot climates, I did a job down in Texas last summer and noticed the synthetic held up fine during install, but after sitting exposed for a couple weeks in 100+ temps, it got kind of wavy - not brittle exactly, but definitely not as tight as when we rolled it out.

I’ve actually had the opposite issue with some synthetics up here in the Midwest - cold snaps made them almost too stiff to lay flat, especially first thing in the morning. Felt’s not perfect, but at least it stays consistent in cooler temps. Wonder if the brand makes a bigger difference than we think?

That’s interesting, because I’ve noticed the same thing with synthetics getting stiff in the cold. We had a job last November where the underlayment felt like trying to roll out a plastic tarp that’d been left in a freezer. Took forever to get it to lay down, and even then it wanted to curl at the edges. Felt definitely seems more forgiving when it’s chilly, but then again, I’ve seen it turn to mush after a few days of rain.

I do wonder if some brands handle temp swings better than others. The last batch we used was a cheaper synthetic and it was a pain in the cold, but I’ve heard the higher-end stuff is supposed to be more flexible. Hard to know unless you try a few out, though. At least you’re not alone - seems like every material has its own quirks depending on where you’re working and what the weather’s doing that week.

That’s pretty much lined up with what I’ve seen. The cheaper synthetics just don’t handle cold snaps well - almost impossible to get them to lay flat, and the curling drives me nuts. I’ve tried a couple mid-range brands and they did seem a bit more pliable, but nothing beats felt for flexibility when it’s cold... until it gets wet, then it’s a mess. For my last project I actually ended up mixing - ran synthetic on the main roof and used felt on the porch where it was more sheltered. Not perfect, but it helped keep costs down and avoided some headaches with installation.

I’ve tried a couple mid-range brands and they did seem a bit more pliable, but nothing beats felt for flexibility when it’s cold... until it gets wet, then it’s a mess.

Mixing underlayments is interesting - did you notice any issues where the felt and synthetic met up? I’ve heard some folks say seams can be a weak point, especially if the porch gets a lot of wind-driven rain. Just curious if that was a problem for you or if it held up fine.

Mixing underlayments is interesting - did you notice any issues where the felt and synthetic met up? I’ve heard some folks say seams can be a weak point, especially if the porch gets a lot of wind-driven rain.

I had the same concern about the seam where felt and synthetic meet. On my back porch, I overlapped the materials by about 6 inches and used a heavy bead of roofing cement at the joint. So far, even after a couple of nasty storms, no leaks or lifting. I do check it every few months just in case. Honestly, I was surprised it held up as well as it did, but maybe I just got lucky with the install. If you’re careful with the overlap and sealing, it seems to work out fine.

Mixing felt and synthetic isn’t my first choice, but I’ve seen it hold up when folks are careful with overlap and cement, like you did. The real trick is making sure the cement gets full contact - sometimes in colder temps it doesn’t bond as well, and that’s when you get those sneaky leaks. I’ve had a couple jobs where wind-driven rain found its way in right at the seam, but usually only if the overlap was skimpy or the cement was too thin. Sounds like you nailed it, though. Funny how sometimes the “temporary fix” ends up outlasting the rest of the roof...

Mixing materials always makes me a little uneasy, but I get why people do it - sometimes you just use what you’ve got or what’s available at the moment. I’ve patched a couple spots with felt and synthetic together (mostly because the store was out of one or the other), and I’ll admit, if you’re careful with overlap and actually take your time with the cement, it can work. That said, I’m still not totally sold on it for anything long-term, especially in places that see wild weather swings.

The cement’s a biggie. I learned the hard way last fall: did a patch job right before a cold snap hit, and sure enough, the bond just didn’t set right. Next big rain, water found its way in along the seam where I thought I’d been generous with cement. Turns out “generous” isn’t enough if it’s not warm enough outside... lesson learned. Now I warm up the cans inside before using them if temps are borderline. Might sound silly but it makes a difference.

One thing I don’t love about mixing felt and synthetic is how differently they move as temps shift. My roof’s got a pretty shallow pitch and when we had that freak windstorm last March, the synthetic held tight but the felt underneath bunched up in one spot - probably my fault for not nailing it down enough. Either way, that seam was never quite right after.

Still, I agree - sometimes those “temporary” fixes just keep going and going while everything else falls apart around them. My neighbor swears by full synthetic now after he had two leaks in spots where he mixed materials. He says it’s worth the extra upfront cost for peace of mind, but honestly? If you’re meticulous with your overlaps and sealants, you can make almost anything last longer than you’d expect.

I guess for me it comes down to climate - hot and humid here most summers, so stuff moves around more than you’d think. If I ever redo the whole roof again, probably going all synthetic just to avoid these weird compatibility issues down the line... but until then? Patchwork it is.

Man, I hear you on the patchwork life. I’ve Frankensteined so many roofs together with whatever was left in the shed, it’s a miracle some of them held at all. That felt-synthetic combo is like mixing oil and water - works until the weather decides to get creative. Honestly, warming up the cement is a pro move. I once tried to rush a patch in January and ended up with a leaky science experiment. Still, those “temporary” fixes sometimes outlast my patience, so I say you’re doing just fine.

That patchwork approach is honestly relatable - my first winter, I slapped down whatever underlayment I could find, and it was pure chaos trying to seal it up. Still, you kept things standing, and that’s what counts. Sometimes the “temporary” stuff really does surprise you.