Felt’s definitely the tortoise in this race—slow and steady, but sometimes just too slow for surprise storms. I’ve seen synthetic hold up way better when weather turns nasty. Still, even the fanciest stuff won’t help if you skip the overlaps or miss nails. It’s wild how a tiny gap can turn into a waterfall inside. I always tell folks: underlayment’s only as good as the install... and the weather’s sense of humor.
- Seen a lot of roofs in all kinds of weather, and I’ll say—felt’s definitely the slowpoke, but sometimes that’s not a bad thing. It’s predictable, you know what you’re getting, but yeah... it can get overwhelmed fast if there’s a sudden downpour or wind-driven rain.
- Synthetics are lighter and usually tougher against water, but I’ve seen some brands wrinkle up or tear if they’re left exposed too long before shingles go on. Not all synthetics are created equal—some are pretty flimsy.
- Overlaps and nails make or break any underlayment. Miss a nail or skimp on overlap, and you might as well leave the attic window open during a storm. I’ve seen leaks that started from a spot smaller than my thumb because someone rushed the install.
- One thing folks forget: even the best underlayment isn’t magic. If your roof deck is rough or you’ve got weird angles (looking at you, old Victorians), water finds its way in eventually.
- Had one inspection last winter where the homeowner used top-tier synthetic, but the crew overlapped it wrong at a valley. First big rain, water tracked right under and dripped into the kitchen light fixture. They were not happy...
- In my area (lots of freeze/thaw cycles), felt sometimes gets brittle over time, especially if it’s exposed before shingles go on. Synthetics hold up better to UV, but only if they’re installed right away.
- For anyone choosing between them: think about your climate, how fast your roofer works, and how picky they are about details. Sometimes “slow and steady” wins if you’re not rushing things... but if storms roll in quick where you live, synthetic might be worth the extra bucks.
- Bottom line: no underlayment will save you from shortcuts or bad luck with weather timing. Always check those overlaps and nail patterns—seen too many good materials wasted by sloppy installs.
- Not sure I’d call felt “predictable” in every climate. In my area (lots of wind and rain), it’s more like a gamble. Once had a job where the felt literally slid off during a storm before we got the shingles down—total mess.
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“Synthetics are lighter and usually tougher against water, but I’ve seen some brands wrinkle up or tear if they’re left exposed too long before shingles go on.”
That’s true, but I’ve noticed some of the newer “eco” synthetics actually hold up better than the cheap plastic stuff. Still, none of them are perfect if you’re leaving the roof open for a week.
- Honestly, I wish more folks would look at recycled underlayments. They’re not mainstream yet, but the durability’s surprised me. Less landfill waste, too.
- At the end of the day, even the fanciest underlayment won’t fix bad install habits or rushing to beat the rain. Just my two cents.
At the end of the day, even the fanciest underlayment won’t fix bad install habits or rushing to beat the rain.
Couldn’t agree more. I’ve seen folks blame the material when really it was just a rush job or not enough fasteners. In my case, I tried felt and synthetic on different projects—honestly, the recycled stuff surprised me too. Held up through a nasty week of spring storms when I had to pause mid-roof. Still, nothing beats getting shingles down quick if the weather’s sketchy.
I’ll admit, I used to think felt was all the same until I tried that bargain roll from the big box store—total regret. It turned into mush after two days of drizzle. Synthetic’s been way better for me, especially when I’m working solo and can’t rush. Still, if you don’t tack it down right, even the fanciest stuff will flap like a flag in a storm... learned that the hard way.
