I’ve actually tried both felt and one of those synthetic underlayments (the blue kind, not green, but similar idea). The synthetic was lighter and way easier to handle—didn’t tear as much, either. It cost more up front, but I noticed it stayed flat even after a couple freeze-thaw cycles last winter. No leaks so far, knock on wood. I get the hesitation about “eco” labels, but in my case, it’s been less hassle than felt. If you’re hiring out, most roofers seem fine with it—mine actually preferred it since it goes down faster.
That’s really interesting to hear how the synthetic held up for you, especially through the freeze-thaw cycles. I’ve seen a lot of roofs where felt just doesn’t bounce back after the weather turns—gets wavy, sometimes even cracks if it’s been stretched too tight. You mentioning,
—that’s pretty much what I’ve noticed on jobs where folks went with the blue or green synthetics.“it stayed flat even after a couple freeze-thaw cycles last winter. No leaks so far, knock on wood.”
I know the upfront cost can sting a bit, but honestly, dealing with fewer tears and less mess when storms hit is worth something. If you’re in an area with wild temperature swings or sudden downpours, it’s peace of mind. I used to be a felt loyalist, but after seeing how some of these synthetics hold up after hail or wind-driven rain, I’m leaning more their way. Not saying felt’s useless, but it’s just not as forgiving.
And yeah, most roofers I know don’t mind making the switch—less weight, goes down faster, and fewer callbacks for repairs. Hard to argue with that.
“it stayed flat even after a couple freeze-thaw cycles last winter. No leaks so far, knock on wood.”
That’s been my experience too—synthetic just shrugs off the crazy weather swings. I remember one job where we tried to save a few bucks with felt, and after the first big storm, it looked like someone had laid down a batch of lasagna noodles. We spent more time fixing wrinkles than actually roofing. I still keep a roll of felt around for little patch jobs, but for full tear-offs? Synthetics all day. Less weight on the back, less stress when the forecast turns ugly.
Funny you mention lasagna noodles—felt always seems to end up that way for me too, especially when the weather gets wild. I’ve switched to synthetic for the big jobs, but I do wish more of these products were made from recycled materials. Anyone found a green synthetic that actually holds up?
