I tried one of those synthetic underlayments when I redid my shed roof last fall. Honestly, it was easier to handle than the old felt stuff—didn’t tear as much, went down faster. But the smell was still there for a while, just different… kind of plasticky instead of tar. Price wasn’t a huge jump, but I’m not convinced it’s a game changer unless you’re dealing with a really steep roof or bad weather. For my main house, I might still stick with felt just because it’s familiar.
Honestly, it was easier to handle than the old felt stuff—didn’t tear as much, went down faster. But the smell was still there for a while, just different… kind of plasticky instead of tar.
That plasticky smell is exactly what threw me off the first time I used synthetic underlayment. I kept thinking it’d go away faster than the tar paper smell, but it sort of lingered in its own way. I get what you mean about sticking with felt for the main house—sometimes the tried-and-true just feels safer, especially if you’ve had good luck with it.
I’m curious though, did you notice any difference in how hot your shed got after switching to synthetic? I read somewhere that some of those newer underlayments can actually reflect a bit more heat, which could be handy depending on where you live. I’m always looking for ways to keep things cooler without running up the electric bill.
Also, since we’re talking about alternatives—has anyone here tried any of those recycled or “green” underlayments? I’ve seen a couple brands at my local supply place but haven’t taken the plunge yet. Wondering if they’re worth the extra few bucks or if it’s just marketing.
I’ve looked into those “green” underlayments, but honestly, the price jump just doesn’t make sense to me for a shed or even most houses. Maybe if you’re building something super high-end or you’re in a spot where code requires it, sure. But for most of us, regular felt or even the basic synthetic stuff does the job fine. I haven’t noticed any real difference in heat with synthetics either—if anything, my shed still gets pretty toasty in summer. I’d rather put the extra cash toward better insulation or a vent fan than gamble on some recycled label.
I get where you’re coming from—those “eco” underlayments can be a tough sell, especially when you’re just trying to keep water out of a shed. I’ve used both the basic felt and some of the pricier synthetics, and honestly, for most jobs, the difference isn’t night and day. Curious though—have you ever tried layering in a radiant barrier or reflective insulation under the roof deck? Sometimes that does more for heat than any underlayment swap. Just wondering if anyone’s had luck with that approach, especially in hotter climates.
- I’ve actually tried radiant barriers under the roof deck in my last place (Texas, so it gets brutal in summer). Honestly, didn’t see a huge difference unless you’re pairing it with proper attic ventilation. The foil stuff helped a bit, but not enough to justify the extra hassle for a shed or outbuilding.
- For sheds, I usually just stick with basic felt. It’s cheap, easy to install, and does the job unless you’re storing something sensitive. The pricier synthetics are nice, but for a simple structure, I don’t see the point.
- Reflective insulation made more sense when I did a metal roof on my workshop. That combo kept things cooler, but again, only because I had vents and some insulation in the walls too. Just slapping a radiant barrier under shingles didn’t do much for me.
- One thing I learned the hard way: if you don’t seal up gaps around the eaves and ridge, all the fancy underlayment in the world won’t stop critters or wind-driven rain from getting in. Had a squirrel nest up there once—total mess.
- If you’re in a super hot area and want to keep things cooler, I’d focus more on shade (trees, awnings) or even painting the roof a lighter color. That made a bigger difference for me than any underlayment swap.
- Not sure if anyone else has noticed, but sometimes those “eco” products just don’t hold up as well over time. Had one start to break down after a couple years—maybe I got a bad batch, but still.
- Bottom line: for sheds and outbuildings, I’d keep it simple unless you’ve got a specific problem you’re trying to solve. For living spaces, then yeah, maybe look at layering and better insulation. But for most folks, basic felt or synthetic is plenty.
