What's this stuff?

[WillyWarbux]

Hi there,

I have some bubbling paint on a hall wall. There's a shower on the other side of this wall so I presume there's water getting through the grout and evaporating through this side?

1. What's the weird fuzzy crunchy white material that's appearing and pushing the paint off the plaster? You can see my finger print left in it, in picture 3.

2. Shouldn't shower walls be covered in some kind of waterproof membrane?

3. What's my best plan of attack? Tiles off, dry wall, re-grout the affected area? I see a few hairline cracks here and there and part of the wall does seem to have sunken in a few mms

Thanks

 

[johnny2007]

Most likely it's what you say, water infiltration, but you better check with a damp meter, in case it's just the finishing plaster falling off because not bonded properly.