Had a crew rush through underlayment once and the roof looked like a potato chip.
That “wavy before shingles” line really hits home. I learned the hard way, too—my roof looked fine from the driveway, but up close it was a rollercoaster. Humidity here in southern Illinois isn’t much different from Missouri, and those thin synthetics just don’t stay put when it’s muggy. I’ve had better luck with the heavier stuff as well. Costs more up front, but I’d rather avoid doing the same job twice... plus I’m not getting any younger crawling around on a hot roof. Slick surfaces are no joke either—thought I was going to end up in the bushes last summer.
- Been there with the “potato chip” look—nothing like seeing your handiwork from the street and thinking it’s fine, then realizing it’s all waves up close.
- I’m with you on the heavier underlayment. Costs more, but I’d rather pay once than fight with it later, especially when it’s 95° and humid.
- Those slick synthetics are a slip-n-slide in the summer. Nearly lost a tool (and my dignity) last July.
- Only thing I’ll add—sometimes the lighter stuff is okay for quick jobs or sheds, but for a real roof, I stick with the thick rolls. My knees thank me.
- Heavy underlayment’s been a game changer for me too. Did my last roof with the thick stuff and haven’t had a single soft spot or weird wrinkle, even after a couple of nasty storms.
- I get why folks use the lighter rolls for sheds or quick fixes, but on a main house? Not worth the gamble. Had to patch up a neighbor’s roof last year—he went cheap and it was already curling up after two summers.
- Those synthetic ones are slick as heck in the heat. Nearly slid right off my own porch roof trying to grab a runaway hammer. Not fun.
- Only thing I wonder—anyone tried those “peel and stick” underlayments? I’ve heard mixed things about how they hold up long-term, especially in places with big temp swings. Worth the extra cost, or just marketing hype?
Heavy underlayment really does make a difference, especially in areas with wild weather swings. I’ve seen fewer issues with leaks and deck rot on homes that went with the thicker stuff. Peel-and-stick has its place—great for valleys or low-slope spots—but in my experience, it can get brittle after a few years if your climate goes from freezing to blazing hot. Not sure I’d use it everywhere, but as an extra layer where water tends to sneak in? Makes sense. Just gotta watch out for installation mistakes since once it’s down, it’s tough to reposition.
Can’t argue with thicker underlayment—definitely noticed less drama with leaks on jobs where we used it. Totally agree peel-and-stick is a lifesaver for valleys, though I’ve seen it go a bit crunchy after a few rough winters. It’s wild how much climate messes with stuff that’s supposed to be “weatherproof,” right?