Damp behind tiles, best course of action?

[churchill67]

Hey all,

After noticing a damp patch by the skirting board on the landing floor, which is just the other side of the shower wall/bathroom, I realised that there were hairline cracks through the grout in the lower tiles towards the bath. Bummer.

I chased the grout out of the tiles at the weekend and the 2 lower tiles literally fell away from the wall behind, as the photo below shows. By no means was the wall behind soaked, but it was certainly damp, and still is 2 days later (albeit it is definitely getting drier).

The cracks were most severe on the horizontal run above these 2 tiles that fell away, and there were hairline cracks that ran up the verticals that have been chased out, and minor ones along the horizontal further up that has also been chased out as well. As a result, I can imagine that the wall behind the 2 large tiles in the centre of the photo may also be a bit damp, although these 2 tiles are certainly stuck fast, which makes me think that most of that section is still okay.

Here's a close up of the wall behind those 2 tiles.

It looks like it's a lath wall behind it, and the wood was certainly flakier than it ought to be when I dug into it a bit with a spade bit...

I've also since realised that on the other side of that wall (which is on the landing), there is a section that has swollen slightly and is now a bit soft to the touch. That's my thumbprint you can see... The soft it is probably 15cm either side of the thumbprint. Note towards the bottom of the wall (approx 10cm below thumbprint) is solid, as is everything 15cm up from the thumbprint.

What do you reckon I should do? Should I look to get all of the damp affected materials removed and replace with new? I'm not entirely sure how this would play out with safely removing the tiles and the section of landing wall... Or would you be tempted to let it all air out/dry out for a few weeks and just whip the two tiles at the bottom back on? I can kinda live with that small section of landing wall being soft to the touch, it's at shin height and it's usually covered by a plant pot. Hmmm...

Any learned advice would be greatly appreciated, and thank you ever so much in advance for any advice you all have!

 

[KenGMac]

The last image you posted is the only one that is visible [to me anyway]

Have a look at the related posts directly below these posts, may give some assistance??

Ken

 

[JaimieH]

The question that needs answering is what has caused the grout to crack in the first place. Unfortunately even if you do manage to dry the plasterboard out, re-fix the tiles and grout, you are still left with the same conditions that caused the issue in the first place. You probably don't want to hear it but I think it sounds like it all needs taking down and starting again. Having said that I can't see any pictures of your tiling, just the wall on the landing. If the affected tiles are inside a shower enclosure the other option is to board over the entire shower walls with one of the many types of wet wall panels. These can be fitted in an entire sheet over your existing tiles in one go, with no more grout lines to crack.

 

[churchill67]

Hey both thanks so much for the replies, my bad on the photos, links fixed now, do they offer any more insight?

Yeah I did have a search around and found lots of discussion about stripping out and retanking, etc., however because of the damp going through to the other side of the wall it made me wonder if maybe there was something slightly more sinister to be aware of...

In the same breath, because of the relatively small patch that is damaged on the bathroom side, I wondered whether it was really worth a full strip out or not? The remaining 90% of the bathroom and tiling itself is otherwise in great condition, so the thought of having to remove more tiles and the likelihood of them cracking in the process and finding myself having to re-tile that wall/the whole bathroom sounds like a bit of a nightmare...

Shall be guided by those with experience though!

 

[KenGMac]

As a quick check, if you can? take off the bath panel and see if the water damage to the plasterboard travels below the bath rim?

If there was a defective bath / tile seal then the water may ??? have been escaping for some time, long enough to damage the plasterboard below the bath rim??

Ken.

 

[JaimieH]

Are you sure that wall is lath and plaster? It looks like stramit board (straw board) to me. This might explain why things have moved and your grout has cracked. If your wall is stramit board and if its as wet as it appears on the photo's then I'm afraid you'll be wasting your time trying to patch things up.

 

[KenGMac]

Nice spot JaimieH.

if you enlarge the image it does appear to be Stramit

As JaimieH posted it really needs to be removed, sorry about that, the material expands, becomes weak, and generally exfoliates in all directions.

Stramit is compressed straw, I do not need to tell you what happens when straw gets wet???

This material was a favorite of Local Authorities back in the day, even used as roof decking panels, absolutely lethal when water got into it.

Ken.