Trying to figure out what to use for a new roof, and it’s honestly kind of overwhelming. I’ve always seen the old-school felt underlayment, but my contractor is pushing synthetic, says it’ll last longer. Thing is, I’ve heard mixed stuff—some people say synthetic can get brittle in extreme heat (I’m in Texas, so, yeah). Felt seems tried and true but maybe doesn’t last as long? Anyone actually had both and noticed a difference after a few years?
Thing is, I’ve heard mixed stuff—some people say synthetic can get brittle in extreme heat (I’m in Texas, so, yeah). Felt seems tried and true but maybe doesn’t last as long?
I totally get the overwhelm. I went through this last year with my own roof (asphalt shingles, Houston area). Ended up going with synthetic since the contractor swore by it, but honestly, I was nervous about the heat too. After two brutal summers, it’s still holding up fine—no weird curling or cracking that I can see from the attic. My neighbor stuck with felt and had some minor leaks after a storm, but he also has an older roof pitch. If you’re watching costs, felt is cheaper upfront, but I figured the extra for synthetic might save me headaches later. It’s a toss-up, but I don’t regret going synthetic so far.
If you’re watching costs, felt is cheaper upfront, but I figured the extra for synthetic might save me headaches later.
I’ve managed a handful of properties around Dallas and Austin, and honestly, I’ve seen both hold up and both fail, depending on the install. Synthetic’s definitely gotten more popular with the roofers I work with, but I’ve had a couple of them mention that not all synthetics are created equal. Some of the cheaper brands apparently do get brittle or even sort of “powdery” after a few years of Texas sun, especially if there’s any delay getting shingles on top. But the better stuff seems to last.
Felt’s kind of old school, but I get why folks still use it. It’s cheap, and if you’re just looking to get a few more years out of an older roof, it’s not a bad call. That said, I had a rental in San Antonio where the felt basically melted into the decking after a few 100+ degree days—made repairs a pain later.
One thing I haven’t seen mentioned much is how long the underlayment is exposed before shingles go on. Had a crew leave synthetic uncovered for almost two weeks during a busy season, and it held up fine. Not sure felt would’ve survived that.
Curious if anyone’s had issues with warranties? I’ve heard some shingle manufacturers want synthetic underlayment for their longer warranties now, but I haven’t dug into the fine print. Anyone run into that? Or is it just marketing?
Had a crew leave synthetic uncovered for almost two weeks during a busy season, and it held up fine. Not sure felt would’ve survived that.
That’s been my experience too—synthetic just seems to handle the sun better if there’s any delay. I’ve seen felt basically bake onto the decking in the summer, which is a nightmare if you ever need to pull it up. As for warranties, you’re right, some shingle brands are picky now. I had to double-check specs on a hail job last year because the manufacturer only honored their warranty with a certain synthetic underlayment. It’s not always just marketing, unfortunately.
Had a similar debate a couple years back when I had to replace a section of roof after some wind damage. I went with synthetic on the advice of the roofer, mostly because they said it’d hold up better if there were delays (and there were, thanks to rain). Haven’t had any issues with it getting brittle so far, but I do wonder how it’ll look in another 10 years. For what it’s worth, the felt underlayment on the older part of the roof was pretty much toast—crumbled apart when we pulled the shingles. Maybe that’s just Texas summers for you.