Honestly, I’m still not totally sold on the synthetics. The “walkable” claim is nice, but I’ve found some brands still get pretty slick, especially first thing in the morning with dew. Felt’s not perfect, but at least I know how it’ll behave—and it’s compostable, which matters to me.
Honestly, I’m still not totally sold on the synthetics. The “walkable” claim is nice, but I’ve found some brands still get pretty slick, especially first thing in the morning with dew.
That’s a fair point about the walkability. I slipped on a synthetic sheet last fall—first job I did after a rain—and it made me rethink just how “walkable” these new materials really are. Some brands have that sanded texture that’s supposed to help, but it seems hit or miss. I’ve noticed the black felt gives better grip underfoot when there’s moisture, even though it can tear easier if you’re dragging tools or bending around valleys.
If you’re trying to decide between the two for longevity, here’s what I’ve seen step-by-step on jobs around here (Midwest, lots of freeze-thaw cycles):
1. Tear-off: Felt usually comes up in shreds if it’s been down more than 10 years, especially if there were leaks. Synthetic comes off in big sheets, even after a decade.
2. Install: Synthetics go down fast because they’re lighter and the rolls are longer. But if it’s windy, they’ll sail right off if you’re not careful—felt hugs the deck better during install.
3. Exposure: Most synthetics are rated for longer exposure before shingling (I’ve seen 6 months+), while felt can wrinkle or even dissolve if left too long in wet weather.
4. Under shingles: Both work fine as long as you get the nailing right and don’t leave gaps. But you’re right—felt is compostable and doesn’t leave plastic bits everywhere when you tear it off later.
One thing that surprised me is how much static electricity builds up with synthetic underlayment. I got zapped a few times when nailing into flashing...never had that with felt.
Bottom line, I still default to felt on smaller jobs or if it’s just a repair. For full tear-offs where we might have to tarp overnight or weather’s unpredictable, synthetics do save us time and headaches with wrinkling. But yeah, I’m still careful walking on them until the shingles are on.
Curious if anyone else has seen certain synthetic brands do better for grip? The stuff we used from GAF was better than some of the generic rolls, but nothing’s perfect.
Walkability is definitely a sticking point for me too. I’ve had crews complain about the slickness of some synthetics, especially in cold or damp conditions—never really had that issue with 30# felt. Synthetics are hard to beat for exposure time and weight, but I’ve also noticed the static buildup you mentioned (one guy got a pretty good jolt off a metal vent last year). For what it’s worth, we’ve had better luck with CertainTeed’s DiamondDeck in terms of traction, but it’s pricier. Still not perfect, though... I tend to weigh the weather forecast and job size before deciding.
Walkability is a huge deal, especially if you’re trying to keep crews safe and moving fast. I’ve seen the same thing—synthetics can get pretty slick, and in the Pacific Northwest where I am, that’s a real problem with all the damp mornings. The static thing is wild, too. I’ve actually heard of a guy getting zapped so bad he dropped his hammer off the roof... not funny at the time, but we laugh about it now.
I get why folks like synthetics for the longer exposure window and lighter rolls, but I keep coming back to the environmental side. Most synthetics are petroleum-based and don’t break down, so they’re just landfill fodder once the roof’s done. Felt isn’t perfect, but at least it’s got some organic content. I wish more companies would push recycled or plant-based options—feels like we’re overdue for something greener that doesn’t sacrifice traction.
Honestly, I’m still torn. I’ll use synthetics on big, complex jobs if the weather’s a wildcard, but for smaller or eco-focused projects, I lean felt. If anyone’s found a truly grippy, less toxic synthetic, I’d love to hear about it...
I hear you on the environmental concerns, but from a durability standpoint, synthetics have outperformed felt in every storm scenario I’ve dealt with. After major hail or wind events, I’ve seen felt tear or saturate way faster. Synthetics aren’t perfect—slippery when wet, sure—but they don’t disintegrate after a week of rain. If the roof’s going to be exposed for more than a day or two, I can’t risk felt anymore. I’d like to see greener options too, but until then, longevity matters most for storm-prone areas.