ᐅ The vapor barrier extends from the window reveal / window jamb.

Hello everyone,

We have been living in our newly built house for a year now. Around the window frames, a kind of silver film keeps appearing. I can cut it off with a knife, but after a few weeks, it comes back. This happens on almost EVERY window.

We have wallpapered and painted everywhere. Does anyone have an idea what this could be?

Thanks in advance!

Could this be the sealing tape? We installed our windows ourselves, and we had to use a sealing tape fixed in place with a special adhesive. On our windows, some of the tape extended beyond the frame, but I simply glued the excess into the reveal with the assembly adhesive, then covered it with plaster and painted over it. Why it keeps happening for you even after trimming is a mystery to me. As far as I know, that material shouldn’t move. At least it didn’t in our case. I’m curious if anyone else has an idea. If in doubt, maybe call in the window installer?