If underlayments could talk: which one would outlast the others?

Still, I wonder if it’s partly about installation or maybe matching the right recycled product to the climate?

I had the same thought. When I put down recycled felt under my porch roof, it was fine until our first big rainstorm - then I found a couple leaks right at the seams. Maybe it’s just not meant for wet climates like mine. Next time, I’m probably going with synthetic even if it costs more. The peace of mind is worth it.

Maybe it’s just not meant for wet climates like mine.

I can relate - tried recycled felt on a rental a few years back, thinking I was being eco-friendly. After one winter, the seams started curling and we had drips in the attic. Could be install, but honestly, our coastal rain just ate it up. Synthetic’s pricier, but I’d rather not gamble with leaks again.

I get the hesitation about recycled felt, especially after reading this:

After one winter, the seams started curling and we had drips in the attic. Could be install, but honestly, our coastal rain just ate it up.

That’s rough. But I’m not totally convinced synthetic is always the answer, even for wet climates. I’ve seen a few neighbors go all-in on synthetic underlayment (the fancy stuff with lifetime warranties), and yeah, it holds up better to standing water and doesn’t wrinkle as much. But when they had to do repairs - like after a tree branch punched through - the synthetic was so slippery and tough to patch that it actually made things harder for them. One guy said he’d rather deal with replacing felt every 10 years than risk sliding off his roof.

I’m in the Pacific Northwest, so rain is basically a year-round thing here too. We did a hybrid approach last time: heavy-duty felt (not the recycled kind) on most of the roof, then a peel-and-stick membrane in the valleys and around penetrations. It cost less than full synthetic but gave us extra protection where leaks usually start. Three winters in, no issues yet - knock on wood.

Not saying felt is perfect (it definitely can curl if installed wrong or left exposed too long), but sometimes I wonder if we’re all getting pushed toward pricier synthetics because they’re easier for contractors to install fast, not necessarily because they’re always better for every situation. Plus, if you ever need to reroof or patch something yourself down the line, felt’s way easier to work with.

Curious if anyone else has tried mixing materials like that? Or maybe there’s some new underlayment out there I haven’t heard of yet... Roofing tech seems to change every time I blink.

Mixing underlayments seems to be the way a lot of folks are going, especially in places where the weather can’t make up its mind. I’ve noticed the same thing with synthetics - great for keeping water out, but man, they turn into a slip-n-slide if you’re not careful. I watched my uncle nearly do a full cartoon banana peel move trying to patch a spot last fall. Not exactly OSHA-approved entertainment.

I’m curious if anyone’s had luck with those newer “breathable” synthetic underlayments? I keep seeing them at the supply house, but haven’t actually worked with one yet. Supposedly they let moisture escape from the attic side but still block rain from above. Sounds good on paper, but I wonder if they really make a difference or if it’s just another marketing angle.

Also, has anyone tried using self-adhered membranes over the whole roof, not just valleys? I’ve heard it’s overkill unless you’re in hurricane country, but I’m not sure if that’s just old-school thinking.

Tried a “breathable” synthetic on a steep roof last spring - was skeptical, but it actually did seem to help with attic moisture, especially after a wet week. Still felt slick as heck underfoot, though. Full self-adhered membrane? Did that once up north after an ice dam disaster. Pricey, but the peace of mind was real... just not sure I’d do it unless you’re dealing with serious freeze/thaw or wind-driven rain.