Odd patch on interior wall...

[buckie10]

Hi Folks,

I live in a tenement flat with a common close and a couple of weeks ago I noticed that a patch of paint (emulsion) on my bit of close wall was "bubbling". Since then it's got bigger and where it has flaked off it looks like the some of the plaster underneath has decomposed (bubbled up) in places too. The patch is now about 12" by 4".

I've traced back to where the patch would be inside the house and it's about halfway up a tiled wall in my bathroom (about a couple of feet above the bath line). Grouting seems to be intact but it is a wall that gets splashed a bit when the shower is used.

Is it likely to be water ingress (egress?) from the bathroom? The wall is pretty thick so I am dubious. Also, the plaster seems dry but if you rub it a bit with your finger it seems to be more greasy or oily on your finger than damp. Should I be worried?

As you can tell, I am not a builder!

Regards,

Buckie.

 

[JayS]

Spot on.

Some half-and-half tiler hasn't tanked the wall before tiling so when you use the show water seeps through the grout. This can really only get worse if you don't do anything...

You have two choices really.

a) remove the tiles and tank the wall (good option)
b) Have baths instead of showers (good option if you have loads of time...)

 

[buckie10]

Right, I've finally managed to get some time to have a proper look at this. Tapping the tiles some sounded "hollow", so I took off 5 or 6 tiles (15cmx15cm) from the row at the bath edge that sounded dodgy and now I wish I'd never bothered!

The plaster on the wall behind only goes down about 3/4 of a tile and below that was all sorts of "packing" (bits of wood, a bit of that expanded foam stuff, thin air, paper... which someone has then tried to plaster over a bit). It stunk, was all really damp and the wetness has seeped into the real plaster and is obviously penetrating right through the wall to the close. I've managed to get all this muck out and get it back to what looks like proper plaster (it doesn't come off when you poke it with a cold chisel although it is a bit soft/damp). At the moment I'm leaving it to dry.

What I'm left with, looking from top to bottom, is 3/4 of a tile of decent wall then it drops back about .75cm before becoming solid again and appears to stay like that in behind the bath so I've also got a .75cm gap between the bath and the wall.

In an ideal world I guess you'd want to remove the bath, plaster and seal the wall, replace the bath and re-tile but I'd rather avoid having to do this if at all possible as that's a big job for big boys. I've never plastered more than a bit of polyfilla so here's the questions...

1) How long will it take to dry the wall out now it's getting air to it?
2) Does it sound possible to patch this bit of wall (1x6 15x15cm tiles worth at the bath edge) and would it be a good idea?
3) Could *I* do it considering I've not done it before but that even I know enough not to plaster and tile over wood and newspaper (I *can* tile, so that bit isn't a problem)?

Cheers,

Buckie.