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

I get the nostalgia for felt, but I’ve actually had better luck with the newer synthetics, especially on some of our bigger buildings. The install is quicker and they don’t wrinkle up as much if there’s a rain delay. Price is higher, yeah, but I’ve found it saves headaches later when you’re dealing with weird weather swings. Maybe it’s just our humid summers, but felt always seems to get a little funky if it sits exposed too long.

Funny, I used to swear by felt just because that’s what everyone used when I first got into managing properties. But after a couple of nasty storms a few years back, I started noticing exactly what you’re talking about - felt just didn’t hold up if it sat out for more than a day or two, especially with all the humidity we get here. Had one job where the crew got rained out halfway through, and by the time they could get back, the felt was already curling at the edges and basically useless. Ended up having to redo that part completely.

I was skeptical about the synthetics at first - mostly because of the price tag - but they really do seem to handle our weird weather better. I’m still not sure they’re perfect for every job, but for bigger roofs or anything that might be exposed for a bit, I’d rather pay more up front than deal with the mess later. Totally get where you’re coming from on this. Sometimes “old school” just means more work down the line...

I get the appeal of synthetics, especially with how unpredictable the weather’s been lately. But I’ll admit, I’m still not totally sold on them for every situation. Maybe it’s just my stubborn streak, but I’ve had a few headaches with synthetic underlayments too - like, they’re supposed to be “walkable,” but I’ve seen a couple brands get slick as ice if there’s any dew or drizzle. Had a buddy take a nasty spill last spring because of that. Plus, I’ve noticed some of the cheaper synthetics can tear pretty easily if you’re not careful, especially around valleys or when you’re dragging bundles across the roof.

Felt’s definitely got its weaknesses - no argument there. I’ve had it turn into mush after a summer thunderstorm more times than I care to remember. But for smaller jobs or quick turnarounds, I still reach for it sometimes. It’s cheap, easy to lay down, and if you know rain’s not in the forecast, it does the trick. Maybe I’m just set in my ways, but I don’t always trust the “latest and greatest” to be worth double or triple the price, especially when some of these synthetics are basically plastic tarps with a fancy label.

I guess it depends on the job and how long you expect the underlayment to be exposed. For a big roof or if there’s any chance of delays, yeah, synthetic probably wins the race. But if you’re just patching a shed or doing a quick re-roof in decent weather, felt’s not totally out of the running yet. Maybe I’m just old school - or maybe I just like saving a few bucks where I can...

Maybe I’m just set in my ways, but I don’t always trust the “latest and greatest” to be worth double or triple the price, especially when some of these synthetics are basically plastic tarps with a fancy label.

Couldn’t agree more - sometimes it feels like you’re just paying for marketing. I’ve had similar issues with synthetic underlayments getting slick, especially early in the morning. For my garage roof last fall, I stuck with felt since I knew I’d finish in a day and the weather was clear. No regrets there. Synthetics have their place, but felt’s still got life left for quick jobs or when you want to keep costs down.

I get where you’re coming from - felt’s definitely not obsolete, especially for straightforward jobs or when you know the weather’s on your side. I’ve found synthetics can be slippery too, which is nerve-wracking if you’re up there early or it’s a bit damp. That said, for longer projects or unpredictable weather, I’ll admit synthetics have saved me a headache or two. Still, for a quick garage or shed? Hard to beat felt for the price and familiarity. Sometimes “new and improved” just means more expensive, not better.

Funny thing, I’ve actually seen felt outlast synthetics in a couple of older homes I’ve inspected - probably because nobody expected much from it, so they left it alone. But I get the hesitation with synthetics being slick; I’ve nearly lost my footing more than once, especially on a frosty morning. Still, when you’re talking about long-term durability and water resistance, synthetics usually pull ahead. Felt’s great for quick jobs or if you’re on a tight budget, but if you want something to “cross the finish line” after years of abuse, synthetics tend to stick around longer... even if they cost more up front. Just depends what you need and how much risk you’re willing to take with the weather.

You nailed it about synthetics being slick - nearly took a ride off a roof myself once thanks to that “ice rink” effect. But I’ve also seen old felt hang in there way longer than anyone expected, especially in places where the sun isn’t beating down all year. There’s something to be said for the “nobody messes with it, so it just keeps going” theory. Still, for sheer water resistance, synthetics usually win the marathon. Either way, you’re spot on - it’s all about what you need and how much risk you’re cool with.

That “ice rink” feeling with synthetics is no joke - first time I stepped on a frosty synthetic, I nearly ended up in the neighbor’s yard. You’re right about felt sticking around longer than folks expect, especially in shaded spots or under tile where it’s not getting baked all day. I’ve torn off 30-year-old roofs and found the old #30 felt still holding together, which always surprises me.

But here’s the thing: if you’re dealing with a low slope or a spot that sees a lot of wind-driven rain, synthetics just don’t wrinkle or tear as easily as felt does when it gets soaked. That said, some of the cheaper synthetics can get brittle after a few years of sun exposure if the shingles aren’t down quick enough. It’s not always a slam dunk.

If you’re in a mild climate and nobody’s walking on the roof much, felt can be fine for decades. But for sheer water resistance and walkability (assuming you get one with some grip), synthetics usually edge out felt - just gotta watch your step when it’s wet or icy. Every job seems to have its own quirks... there’s no one-size-fits-all answer.

You nailed it about the quirks - every roof’s got its own personality. I’ve seen synthetics hold up great after a hailstorm, but on a hot Texas summer, some brands just crisp up if left exposed too long. Felt’s old-school, but in shaded or protected spots, it really can surprise you with how tough it is. For storm-prone areas though, I lean synthetic for that extra tear resistance. Just gotta be careful on those frosty mornings... learned that lesson the hard way myself.

That’s a good point about synthetics getting crispy in the heat. I’ve seen a few jobs where the underlayment looked fine after a storm, but then a month of sun just baked it. I’m always curious how the “eco” options stack up - like those recycled-fiber felts or the newer plant-based synthetics. Anyone actually seen those hold up in real-world weather, or do they just sound good on paper? I’d love to use greener stuff, but not if it’s gonna fall apart after one Texas summer.

I’d love to use greener stuff, but not if it’s gonna fall apart after one Texas summer.

I totally get where you’re coming from. I’m in central Texas and just went through my first summer as a homeowner, so I’ve been obsessing over this exact thing. The heat here is brutal - like, you can fry an egg on the driveway by noon. We had our roof redone last year (asphalt shingles) and I really wanted something eco-friendly under there, but honestly, most of the contractors just kinda shrugged when I brought up recycled or plant-based options. One guy even said, “You want to be green or you want it to last?” which felt a little harsh, but... yeah.

I did a ton of research anyway and found one brand of recycled-fiber felt that looked promising. The reviews online were all over the place, though. Some folks said it held up fine for a season or two, others mentioned it curling or getting weirdly brittle after a couple months of sun. I couldn’t find anyone local who’d actually used it long-term, which made me nervous.

In the end, I chickened out and went with a synthetic because I was terrified of leaks. Now I’m watching my neighbor’s house - he went with one of those “eco” felts last spring. It seemed okay during the first few storms, but now (after this last heatwave) I noticed some edges poking up under his shingles. Not sure if that’s installer error or just the material giving up.

Honestly, I WANT these greener options to work. But until someone in my area can point to a roof that’s survived three Texas summers without issues, I’m probably sticking with what’s tried and true - even if it makes me feel a little guilty about the landfill situation.

If you do end up trying one of those newer underlayments, would love to hear how it goes for you down the line. It feels like we’re all kind of guinea pigs on this stuff...

It’s wild how much the sun just eats through stuff here. I actually tried a “green” underlayment on my shed as a test run (figured if it failed, at least it wasn’t over my living room). After one summer, parts looked kinda crispy and started curling up at the edges. Not the confidence boost I hoped for. Maybe the tech will catch up, but for now, I’m with you - too risky for the main house.

After one summer, parts looked kinda crispy and started curling up at the edges.

That’s exactly what I’ve seen on a few inspections - these “eco” underlayments just don’t seem to handle UV like the old-school felts or synthetics. Curious if you noticed any difference in how the fasteners held up? Sometimes the underlayment fails but the staples or nails are still solid, which is odd. Wondering if anyone’s had better luck with the higher-end synthetics, or is it just a matter of time in this sun?

I’ve seen the same thing - edges curling, but the nails or cap staples are still in there tight. It’s weird. I tried one of those “premium” synthetic rolls on my shed last year, and honestly, it didn’t hold up much better. Maybe it’s just our brutal sun? Anyone ever try doubling up layers, or is that just a waste?

Doubling up layers always sounded good in theory, but in practice? I tried it once on a little lean-to I built for firewood. Used two layers of the cheap felt, thinking it’d be twice as tough. All I got was more curling at the edges and a lot more hassle with the nails. Didn’t seem to help with leaks either - water still found its way in at the seams after a couple seasons. Maybe if you’re in a colder climate it’d make sense, but here (central Texas), the sun just bakes everything. Doesn’t matter if it’s “premium” or bargain bin, that UV finds a way.

I’ve also noticed those synthetics get brittle after a year or two. They go on nice and flat, but then you come back and they’re curling up like potato chips. The staples are still holding, but the material itself just shrinks or something. I’m starting to think the only real answer is to get the shingles or metal on as soon as possible and not trust any underlayment to last more than a few months exposed.

If you’re dealing with a shed or something you don’t mind redoing every few years, maybe it’s not a big deal. But for my main roof? I’d rather spend the money on better shingles and just use whatever underlayment is cheapest, since none of them seem to win the “marathon” around here.

Funny thing - my neighbor swears by old-school 30# felt, says he’s never had an issue. But he’s also got a ton of shade from big oaks, so maybe that’s the trick. If you’ve got full sun all day, I don’t think doubling up does much except lighten your wallet.

Anyway, just my two cents. If anyone’s actually had luck with layering, I’d be curious, but I’m not holding my breath...

I hear you on the Texas sun just destroying everything. I tried doubling up felt on a shed roof a few years back, thinking it’d buy me some extra time before I got around to shingles. Didn’t really help - edges curled up, and the wind just made it worse. Ended up with leaks anyway, and honestly, it was more work for nothing.

I’ve messed with both the cheap felt and some of those synthetic rolls. The synthetics looked promising at first - super light, easy to roll out - but after one summer, they started cracking and curling too. Maybe they’d last longer up north, but here? Not seeing much difference.

My neighbor’s got a metal roof with just one layer of underlayment, and his place is holding up fine. Makes me wonder if all this fuss over underlayment is worth it when the real battle is against the sun and heat. At this point, I’m leaning toward spending less on underlayment and more on whatever’s actually going to be exposed long-term. Just seems like none of them are built for our kind of weather...

That’s been my experience too - felt or synthetic, neither one stands a real chance against the Texas sun. I’ve patched up more than a few roofs where the underlayment just gave up after a couple summers. Honestly, I’ve started thinking of underlayment here as more of a “get you through install” thing, not long-term protection. Metal roofs seem to shrug off the heat way better, and if you’re spending money, might as well put it toward what’s actually facing the elements every day. The sun here just eats everything alive... no magic fix I’ve found yet.

I hear you on the Texas sun - nothing like watching a brand new underlayment start curling up before the paint’s even dry on the fascia. I’ve seen synthetics hold out a little longer than felt, but honestly, it’s a race to the bottom either way once July rolls around. Metal roofs definitely seem to take the punishment better, and at least you’re not redoing the underlayment every few years. Still, I wish there was something that could actually last more than a couple seasons... maybe in another decade?

I’ve been battling the same thing for years - felt, synthetic, peel-and-stick, you name it. The Texas heat just eats everything alive. I went with a “premium” synthetic last time thinking it’d buy me a few more years, but by the second summer, it was already looking tired. Maybe it lasted a bit longer than the old black felt, but not by much.

Metal roofs are tempting, but the upfront cost is no joke. I did the math and, for my place, it’d take at least a decade to break even compared to just redoing shingles and underlayment every few years. Plus, my neighbor’s metal roof sounds like a drumline during hailstorms - kind of funny until you’re trying to sleep.

Honestly, I wish someone would invent an underlayment that could handle this sun without turning into potato chips by August. Until then, I’m just patching as needed and keeping a close eye on the attic for leaks. If anyone ever finds something that actually lasts, I’ll be first in line... but I’m not holding my breath.

I hear you on the Texas sun - mine’s not quite as brutal (I’m in central Oklahoma), but it still cooks everything. I tried a high-temp synthetic last time, thinking it’d be the magic bullet. Nope. By year three, it was curling at the edges and brittle in spots. What’s worked best for me so far is layering: I put down a basic synthetic, then a peel-and-stick just along the eaves and valleys. It’s not perfect, but it seems to slow down the damage where leaks usually start. Still, nothing I’ve tried has really “won the race” against the heat. Just feels like a game of buying time.