How long to leave a wall to dry after water damage?

andre_xs

Hi All,
we had a water damage from the upstairs bathroom. The silicone seal around the shower wasn't waterproof anymore, and after a while water came through. It's heavy on one side of the wall (see pic), and you can see a slight watermark on the other side of the wall as well.

On the side shown in the pic, the plaster came up a little bit, it's getting crumbly. It's a couple of weeks now since it happened and it appears dry now (which is why the plug is in). Would sanding down the plaster for a smooth surface and painting over it be sufficient?

How long should we wait with that work (how long will humidity stay in the walls)?

Kind Regards,

Andre

stuart45

Looks like the plaster has blown, so it would probably be better to hack it off and replaster that bit.

FreeBear

If it is a plasterboard wall with a drywall box, you may need to cut the plaster back to studs either side and replace the PB. On the bright side, it will dry out fairly quickly (weeks instead of months).

coffeehound

It looks as though the pattress box has sunk back into the wall a bit (?)

bris

About 2 weeks is the answer you are looking for.

Bendy_House

Hi Andre.

Very good chance this is salvageable. It would be good to remove that socket, tho', whilst you tidy up the wall surrounding it - cut the power, unwire the socket, fit the cable ends into screw-terminals, tape them up safely, and push it into the back box so's it's totally out of the way.

Then scrape away all the loose, flaky paint, and see what you have. If the plaster is very crumbly, then gouge it away until you reach more solid stuff. If it's only powdery on the surface, then sand it back using coarse paper.

Then use a suitable filler to make good, dampening the existing plaster a bit first so's it doesn't suck all the moisture out of the new skim. Once fully dry, sand it flat.

Paint. Be chuffed.

Clean the other side using a damp cloth and some detergent - see how much of the stain you can remove. Once dry, sand it to clean it up a bit more, and then apply a coat of paint. If the stain shows through, then you may need to use a stain-blocker first. Same applies to the worst side...

 

andre_xs

Thanks for the replies. It's a brick wall (house is build in the 1950s), no plasterboard, and it has been skimmed when we moved in a couple of years ago. Not sure about the exact type / nature of the bricks though. I think it's the red solid type (upstairs we have the grey one with wholes which looks a bit like a sponge - you can see, I'm not a builder  ).

I guess if we repair (like skim over again or sand even, depending on the state of the current plaster) and we do it too early while the wall is still we on the inside, the worst which could happen is that the new plaster blows up again? But it's not like we would trap the humidity and cause permanent damage / mould?

stuart45

Originally it was probably 2 coats of sand/cement and a plaster skim. The socket might have been cut out later and filled which is why it's sink back a bit.