I've noticed ambient temp makes a bigger difference for me. Had a job last summer where the membrane was pretty standard thickness, but it was scorching outside... had to dial way back on heat or risk melting through. Learned that lesson quick, haha.
Yeah, ambient temp definitely plays a bigger role than most people realize. I had a similar experience last summer—thought I had my heat settings dialed in perfectly from a previous job, but the next day was like 15 degrees hotter and suddenly I was melting through like butter. Had to back off the heat way more than expected. Honestly, I think it's less about a specific number being "too hot" and more about adjusting on the fly based on conditions. I've seen guys stubbornly stick to their usual settings and end up patching holes all afternoon... not fun. Best advice is just pay attention to how the membrane reacts as you go—if it starts looking glossy or feels too soft under your roller, ease up quick. Better to slow down a bit than spend hours fixing mistakes later, trust me.
Couldn't agree more about adjusting on the fly. I've inspected plenty of roofs where you can tell someone was determined to stick to their "perfect" settings no matter what. You end up seeing seams that look like melted cheese sandwiches—funny for me, not so funny for whoever has to fix it later.
Honestly, ambient temp is sneaky. You think you're good because yesterday was fine, but today the sun decides to crank things up and suddenly you're playing catch-up. I've even seen guys try to blame their equipment when it's clearly just the weather messing with them. Like you said, watching how the membrane reacts is key—if it starts looking shiny or gooey, that's your cue to back off a bit.
Better to slow down and get it right than rush through and leave behind a mess you'll regret later. Trust me, I've seen enough patch jobs gone wrong to know it's worth taking your time...
- Glad I stumbled onto this thread... just had my roof done with TPO and now I'm wondering if they paid attention to temps.
- Didn't even realize ambient temperature could make such a big difference. Makes sense though, especially after reading about the melted cheese sandwich seams, haha.
- Quick question for you experienced folks: if the seams look decent now, could issues still pop up later from welding at the wrong temp? Or would problems be obvious right away?
- Just trying to figure out if I should keep an eye out for anything specific down the road. Thanks!
Had a similar worry when we got our TPO roof done last summer. Everything looked fine at first, but after a few months, noticed a couple seams lifting slightly—nothing major, but enough to make me wonder about the welding temps. Roofer came back and fixed it quick, said sometimes issues don't show immediately. I'd just keep an eye out after big temperature swings or storms... better safe than sorry, right?
