Yeah, welding TPO is definitely trickier than it looks. I've seen roofs where the installer cranked up the heat thinking hotter = better seal, but ended up scorching the membrane instead. It's all about finding that sweet spot—not too hot, not too cold... Goldilocks roofing, basically.
I've seen a few roofs with that same issue—heat dialed up way too high, leaving behind those ugly scorch marks. From what I've gathered, most manufacturers recommend a welding temp around 900-1000°F, but it can vary based on weather, membrane thickness, and even your welding speed. I'd say start lower and slowly bump it up until you find the right balance. Better to take your time than end up with crispy TPO...
"Better to take your time than end up with crispy TPO..."
Couldn't agree more. Learned that lesson the hard way a few summers back when I helped my brother-in-law redo his garage roof. We figured hotter meant faster, right? Nope. Ended up with a nice line of scorch marks that looked like tire tracks across the membrane. Had to redo half the seams—total pain. Now I always start lower and ease up slowly, especially on hot days. Saves headaches later.
"Ended up with a nice line of scorch marks that looked like tire tracks across the membrane."
Haha, been there myself—those scorch marks are like battle scars reminding us to slow down. A few years ago, I was inspecting a roof job where the installer clearly rushed through on a blazing hot afternoon. The seams looked decent at first glance, but when I did a closer check, the membrane was brittle and cracking along the weld lines. Turns out the guy had cranked the heat way up to speed things along. Not pretty, and definitely not watertight.
I've noticed that ambient temperature plays a bigger role than people realize. On cooler days, you can bump the heat slightly, but when it's already scorching outside, even moderate heat settings can push things over the edge. Makes me wonder—do you guys adjust your welding temps based on weather forecasts, or just go by feel as you work? Curious how others handle that balancing act...
I'm new to this stuff, but seeing scorch marks described as "battle scars" makes me feel a bit better about my own attempts, haha. For those of you who've been doing this awhile, is there like a sweet spot temp-wise, or is it mostly trial and error?
