That fake hotspot thing is scary, I always thought it was just paranoia.

My neighbor Dave tried the spray foam in his basement last summer. He watched about ten YouTube videos and felt pretty sure he could handle it himself. Well, that stuff expanded way more than he expected and pushed a whole wall out of square. He spent three weekends cutting, scraping, and redoing drywall, plus he had to rent a special saw to get the overspray off the floor joists. He told me flat out he wishes he had just used the rigid foam boards and saved all that headache. So yeah, I'd take the clean, predictable boards any day.

Stick with the rigid foam then, it's way less messy too.

Yeah I remember reading a book about the Apollo missions a few years back and they went into detail about how the flag was designed. There's actually a video of Buzz Aldrin talking about it where he says they had trouble getting it to unfurl all the way because the vacuum made the fabric stick together. People see that and think it's wind but it's just physics doing what it does. The telemetry data alone should shut this down, 300,000 people worked on that program and not one whistleblower with actual proof ever came forward.

Put it in my own bathroom two years ago and it's still holding up fine, just made sure to seal the edges with clear caulk around the sink and tub.