WINDOWS ACTING WEIRD AT HIGH ALTITUDE - ANY IDEAS?

"The windows were fogging up like crazy and seemed harder to open and close than usual."

Yeah, I've had that happen a few times at our family cabin. Usually it's just the altitude and temperature swings messing with the pressure inside the double-pane windows. Makes them fog up and sometimes even warp a bit, which explains why they're harder to open. It's annoying, but usually harmless. If it keeps happening though, might wanna check the seals - could be they're starting to fail.

I've seen this happen too, but honestly, I'd be careful about dismissing it as just altitude or temperature swings. Fogging inside double-pane windows usually means moisture has gotten trapped between the panes, and that's not exactly harmless. It can actually reduce the window's insulating properties quite a bit, making your heating bills creep up without you even noticing.

If you're noticing they're harder to open and close, it might not just be warping from pressure changes - could also be swelling from moisture buildup around the frames. I'd suggest taking a closer look at the window frames themselves. Check for any soft spots or discoloration, especially around the edges. If you find anything suspicious, drying it out thoroughly and resealing the edges can help temporarily, but long-term you might need to replace the affected panes or even the whole window.

I know it's tempting to shrug it off as just a minor annoyance, but catching these things early can save you a lot of headaches (and money) down the road...