- I get the worry about over-sealing, but in my experience, foam strips don’t usually trap enough moisture to cause real issues unless there’s already a leak or condensation problem.
- Sometimes it’s actually the old window glazing or failed caulk outside letting water in, not the foam itself.
- I had bubbling paint too, but turned out my storm windows weren’t vented right—fixed that and no more damp trim.
- Totally agree it’s a balance though... airtight is great for heat bills, but you still need airflow or you wind up with mold.
- Maybe worth checking for leaks from the outside next time? Sometimes it’s not where you expect.
Had a job last winter where the homeowners were convinced their new foam strips were the reason the window trim kept getting soggy. They were ready to rip ‘em out and just go back to living with drafts. Turns out, the real culprit was a gutter that dumped water right onto the window frame every time it rained. Water was sneaking in behind the siding, not through the window at all. Sometimes it’s like playing detective—just gotta follow the clues (and sometimes get soaked in the process).
I’m with you on the airflow vs. airtight debate. Folks always want to seal everything up tight as a drum, but then they call me a year later asking why their house smells like a locker room and there’s mildew creeping up the walls. If you’re off-grid and relying on wood heat, you notice it even more—too tight and you can’t get a good draft in your stove, too loose and you’re burning through wood like crazy.
One thing I’ve started doing is putting those little trickle vents in storm windows when I replace ‘em. Not enough to let in a big draft, but gives moisture somewhere to go besides your paint or sills. Anyone else tried those? I still get folks who think it’s nuts to add holes to a window, but it’s solved more problems than it’s caused for me.
And yeah, outside leaks are sneaky. I had one where water was coming in from three feet above the window—bad flashing on the roof—and just running down inside the wall ‘til it popped out by the sill. You’d never guess just looking at the bubbling paint.
Bottom line, drafty windows mess with more than just your toes in winter—sometimes it’s your whole wall system getting soaked or your air quality going sideways. Anyone else ever chase a leak for weeks before finding it way up where you least expected?