Couldn’t agree more about trusting your senses over just chasing numbers. I’ve tried using temp guns and all that, but half the time the readings are all over the place, especially if there’s a breeze or the sun’s moving in and out. I’ve definitely learned the hard way that a glossy seam or that burnt smell means you’re pushing it too far. Had to patch up a section last year because I got distracted and didn’t notice the welds were getting brittle—lesson learned.
I’d add, sometimes folks get too focused on speed, thinking faster is better. But honestly, I’d rather take it slow and get a solid bond than rush and end up with leaks down the road. And yeah, every roll of TPO seems to have its own personality. I’ve had some brands that just don’t like the same settings as others, even if they’re supposed to be similar.
Weather’s a huge wildcard too. Here in the Midwest, you can start the day in a hoodie and end up sweating by noon. Makes a big difference in how the material reacts. I keep a few scraps handy for test welds, just like you said—it’s saved me more than once.
- 100% agree on not just chasing numbers.
Couldn’t have said it better—numbers are only part of the story.“I’ve tried using temp guns and all that, but half the time the readings are all over the place, especially if there’s a breeze or the sun’s moving in and out.”
- Speed kills, honestly. I’ve seen too many “fast” welds fail after one season. Slow and steady is underrated.
- Midwest weather is wild. I’ve had welds go from perfect to brittle in an hour when the clouds clear. Test scraps are a must, but I still get nervous with some of these newer TPO blends... they just don’t act like the old stuff.
- Not sure there’s ever a “perfect” setting—just gotta stay alert and trust your gut more than the dial.
I totally get the nerves with these new TPO blends. When I had my roof done last year, the crew kept checking seams by hand instead of just trusting the temp gun. They said the readings were all over the place, especially when a cloud rolled by or the wind picked up. I was surprised how much they relied on feel and experience instead of just numbers. Honestly, watching them take their time made me realize faster isn’t always better—my neighbor’s roof was done in a rush and he’s already patching seams. Guess there’s no shortcut for a solid weld.
That’s interesting, because I asked my roofer about using just the temp gun and he kind of shrugged it off. He said,
Did you notice if your crew used different settings for shady spots? I keep wondering if there’s a risk of overheating the seams and actually making them weaker, not stronger. My neighbor had bubbling after a hot day—could that be from too much heat during install, or is that something else?“the readings were all over the place, especially when a cloud rolled by or the wind picked up.”
“the readings were all over the place, especially when a cloud rolled by or the wind picked up.”
Yeah, that sounds about right. I watched my crew last summer and it was like a dance—one guy with the gun, one with the welder, both arguing about whether it was “too sunny” or “not sunny enough.” They did crank down the temp in shady corners, but honestly, it felt more like guesswork than science. As for bubbling, I’ve seen that after a scorcher—sometimes it’s trapped moisture, sometimes just too much heat. My neighbor’s roof looked like a giant marshmallow after his install… not exactly confidence-inspiring.
