Painting over water stains

[sedalbis]

Hello everyone,

We recently had a bedroom completely replastered. Once the plaster was dry, we used white emulsion mixed 50 50 with water to paint all the walls and ceiling. We did 2 coats like this and then the final coat was 100% white emulsion and it looks great.

Unfortunately, our roof has since had a leak and there is a large area of water staining in the bedroom on the ceiling and on the top of the wall. Our roofer is coming to fix the problem on Tuesday.

Once I've given it a week or so to dry out, how do I go about covering up the staining? I'm hoping we don't have to remove the plaster and can just paint over it? Can I just use 100% emulsion again or will this not work?

Any advice would be much appreciated. Many thanks in advance

 

[opps]

water stains will probably bleed through subsequent coats of water based emulsion.

I tend to use Zinsser BIN to cover them. It is shellac based and dries very quickly. (use a throw away brush, or purchase household ammonia to clean the brush). Then paint over it will your emulsion. It ain't cheap though. If you have some oil based emulsion, you can use that instead but you will have to wait 16 hours to recoat

unless the plaster is blown (sounds hollow when you tap it) you should be ok to leave it and just BIN/etc over it.

 

[sedalbis]

Thank you! Just had a look and that stuff looks amazing.

 

[ic1927]

BIN is great for water stains, I'd use a mini foam roller to put it on the water stained ceiling so you don't see brush marks when you go over it with the emulsion.

 

[opps]

BIN is great for water stains, I'd use a mini foam roller to put it on the water stained ceiling so you don't see brush marks when you go over it with the emulsion.

Foam rollers will double in length and go floppy if you use them for more than a few minutes though.

 

[London Mike 49]

If you have any oil based undercoat, then a coat of that then 16/24 hours to dry then 100% emulsion.

Mike

 

[ic1927]

Foam rollers will double in length and go floppy if you use them for more than a few minutes though.

Yes but at a quid for a pack of five in the pound shops you use them once and then 'bin' them, pardon the pun.