TP Home | About | Newsletter | Blogs |

How to check for dried paste from old wallpaper

Since joining this site my knowledge has increased dramatically,on my next project i have a room to paint,of a Friends,the room was wallpapered now painted,not sure if they followed correct preparation,What worry s me i am going to paint the walls and there will be problems,i have used tape on wall to check adhesion,and wiped with wet finger to check for a powdery surface,but wallpaper glue cant be seen or can it,is there a test for that,you can do to see if glues still on wall,is it a case off waiting to see if paint starts crazing then worry,if the previous paint looked OK ,then no reason why there should be any problems.How do i solve if i do get problems,is it the bullseye sealer,i am thinking a bit ahead but like to have the knowledge up them sleeves :stuck_out_tongue: when needed. :stuck_out_tongue: .

hard to say without seeing it, depends how long the existing wallpaper has been up, but from what you describe I’d quote to strip, prep, line and paint.

Is there no signs you can see the wall paper glue is still on wall.

[quote]Quote from darlic on December 18, 2013, 21:10
Is there no signs you can see the wall paper glue is still on wall.

If you want to go this route, the dark patches are where I hadnt yet sanded off the ceiling after stripping old paper.

1 Like

Andy thanks,so look out for dark patches on plaster,but what like it has been painted already then what do you look for,to see if the correct preparation has been done

Get it all prepped ready for finish coats.

Prime it with Zinsser Gardz


EDIT: This assumes you can get the prep to the level you want for painting. Dave’s lining approach is a more forgiving route, still need to make it smooth and bit-free but lining would make a uniform surface.

If you have a phone, take pictures so we can get a better idea of what the difficulties are, cheers

If the walls were once papered, stripped and then painted and you can’t see any crazing or flaking it’s not very likely another coat will cause any problems. If you are really worried then Andy’s idea of using Zinseer Gardz is the best option.
I follow Dave’s way when removing paper (strip, prep, line and emulsion). Definitely safest!

so crazing is the main issue to look out for,and,dark patches on bare plaster,very interesting,but crazing could be caused by a number of things if i am correct,not just paint.

Bare plaster is another subject I was under the impression the walls were already painted. Yes crazing can be caused by other things but if you know a wall has been stripped and the paint crazes when dry it likely to be paste residue.

Experience is a great teacher,tonight my friend asked me to quote for a ceiling,where he had wallpapered the walls he left paste ,on ceiling,if he hadn’t off said i wouldn’t have recognized it,it was a slight patch of sheen on a Matt ceiling a valuable lesson.