That’s a good call—pushing through the heat can backfire, even if it looks fine at first. I’ve noticed the same thing with TPO, especially when the sun’s beating down and the membrane gets almost tacky. Early starts make a huge difference, even if it means longer days. Sometimes it’s just not worth risking a callback.
- Ran into this last July—membrane was almost melting under my boots by noon.
- Tried pushing through, welds looked fine but half failed the probe test later.
- Shade tents helped a bit, but honestly, after 90°F on the deck, it’s just not worth it.
- Anyone else notice seams get weirdly glossy when it’s too hot? Not sure if that’s just me...
Yeah, I’ve seen those seams get super glossy when it’s roasting out—almost like they’re sweating. Last summer, we tried to keep going after lunch and the membrane was so soft my footprints were showing up. Welds looked textbook at first, but half of them peeled right up with the probe later. Not sure if it’s just the brand we use or what, but once that deck hits 95°F or so, it’s like fighting a losing battle.
What’s worked for us is starting crazy early—like sunrise early—and calling it by noon if it’s a scorcher. Shade tents help a bit, but honestly, sometimes you’re just baking yourself and the roof for nothing. I’ve heard some guys drop their temps on the welder when it’s hot, but then you risk cold welds if you go too far. It’s kind of a balancing act.
If you see those seams getting shiny and almost sticky, that’s usually my sign to pack it in for the day... or at least take a long break in the shade.
That’s interesting about the welds peeling up after looking perfect at first—definitely seen similar issues during inspections. I’ve noticed some crews try to cool the surface with water or wet towels before welding, but I’m not sure it makes a big difference once the membrane gets that soft. Have you ever tried using an infrared thermometer to check the actual surface temp before starting? Sometimes the air temp is only part of the story, especially on darker substrates. Wonder if there’s a sweet spot for surface temp that’s more reliable than just going by feel or appearance.
I’ve actually tried the infrared thermometer thing a couple times, mostly after getting burned by welds that looked fine but failed later. It’s wild how much hotter the membrane gets compared to the air, especially on black or even gray surfaces. I found if it’s reading over 140°F, the welds get sketchy—edges start curling or you get that weird bubbling. Cooling with water never really worked for us either, just made more mess. I’d trust the temp gun way more than just guessing by touch, honestly.
