Watermarks in wallpaper after decorating

[pt_robertson]

We just redecorated the hall with white blown vinyl and now find what I would describe as watermarks or tide marks in a lot of places. It has defintiely dried out so not just still drying out (about 2 weeks ago now)

The walls were clean (washed) and paste and paper were of course clean as well so dont understand where these stains come from.

A collegue thought it sounded like the marks you get in damp walls when they get wet (say from bath steam) as it draws out the salt but I didnt understand this.

We do have damp but not in this part of the house (I had tested it previously) so didnt think it could be this.

Any thoughts on what caused it - and any solutions?

Cheers!

P

[Pat Robertson]

Has noone any theories about this?

cheers!

P

[Stuart Noble]

No. I can't think of anything that would get through blown vinyl from the wall. It's pretty much waterproof. Try leaving a puddle on an offcut and see if it goes anywhere. The rust stains your colleague refers to will show through normal lining paper but not usually vinyl. If you're going to paint it, try emulsion on a section and see if it shows through after a couple of days. If it does, you'll need to seal it with an oil based undercoat. In this event, apply early morning and go out for the day. The fumes are pretty bad