- Heat exposure might matter, but I've seen gummy welds even with fresh rolls straight from the supplier.
- Could be more about ambient humidity or even subtle variations in welding technique...
- Not convinced storage alone explains it fully.
I've noticed similar issues myself, even when I was careful about storage conditions. You're onto something with humidity—I've had days where the welds just wouldn't cooperate, and it turned out the humidity was unusually high. Technique definitely plays a role too; subtle changes in speed or pressure can make a surprising difference.
One thing I've learned over time is that TPO welding seems to have a sweet spot temperature-wise. Too hot, and you get gummy welds; too cool, and the seams don't bond properly. But even when you're dialed in perfectly, environmental factors can still throw things off. I remember one summer afternoon, fresh roll straight from the supplier, everything seemed perfect... but the welds were gummy and inconsistent. Turned out the humidity was through the roof that day. Next morning, same roll, same settings—perfect welds.
So yeah, storage alone probably isn't the full story. It's more likely a combination of factors: ambient conditions, slight variations in technique, maybe even subtle differences between batches from the manufacturer. Roofing materials can be finicky like that.
You're definitely asking the right questions though—figuring out these nuances is half the battle.
- Totally agree about humidity messing things up... had a similar experience last summer. Thought I was losing my touch until I realized how muggy it was.
- I've found around 950°F to 1000°F usually works best for me, but even then, some days are just off.
- Curious if anyone's noticed differences between brands or batches? I swear some rolls weld easier than others, even under identical conditions.
- Also, does wind ever affect your weld quality? Had a breezy day recently and welds seemed weaker, but maybe it was just me...
"Curious if anyone's noticed differences between brands or batches? I swear some rolls weld easier than others, even under identical conditions."
Yeah, I've definitely noticed this too. Last summer, when I was patching up my garage roof with TPO, I switched brands halfway through (ran out of the first roll, rookie mistake lol). The second roll was a nightmare—same heat settings, same technique, but it just wouldn't bond as cleanly. Thought it was me at first, but after reading your comment, maybe not.
Wind is another sneaky factor. Even a slight breeze seems to cool things down quicker than you'd expect. Had to rig up a makeshift windbreak with plywood sheets once just to get a decent weld. Felt kinda silly doing it, but hey, it worked.
Speaking of external factors, has anyone noticed if direct sunlight versus shade affects weld quality? I've had mixed results and can't quite pin down if it's coincidence or something legit.
I've definitely run into this too. At first I thought it was just me being inconsistent, but after a few jobs, it's clear some rolls just weld differently. Even batches from the same brand can vary—maybe storage conditions or something?
About sunlight vs shade, I've noticed welding in direct sun seems to make things trickier sometimes. The membrane heats up quicker, and if you're not careful, you can easily overheat it without realizing. Shade feels more forgiving somehow... gives you a bit more control over the heat.
Wind is definitely underrated as a factor though. Had one job where even a gentle breeze made my welds look amateurish until I figured out what was going on. Felt pretty dumb once I realized it was just the wind cooling things down too fast.
Anyway, glad I'm not alone here—thought I was losing my touch for a minute there, haha.
