Shower Walls - Vertical Cracks & Tiles Coming Away from Wall

[CRB81]

We had a new en suite with shower fitted as part of a refurb last year. We're a lower ground/basement flat in a Victorian conversion and this 'new' room is basically our old bathroom annexed off. Everything was replastered and/or fitted 4-8 weeks before the tiling took place.

Since then we have had two tiling problems that need to be fixed.

First, a tile in the bottom corner of the shower has started to pull away from the wall. It is an internal wall where it meets the external wall, and in the few months since this happened a vertical crack has started running up the tiles above. It looks like movement in the wall itself.

https://drive.google.com/file/d/1zXCERBOBbI0RzD6j2LIL7_kl7MW1XzTi/view?usp=sharing

It's a load bearing wall and there is a brick wall/pillar behind the crack. With wood behind the rest of the wall in the shower area.

https://drive.google.com/file/d/1gBKgReTx_FqaMZzsFnVCxPjmzVbS28mw/view?usp=sharing

Second, the tiling on the adjacent wall has started to come away from the ground up along the trim edging.

https://drive.google.com/file/d/13L9dIw8RzS7BObNb0SqVPSUcLGQendRp/view?usp=sharing

I know the main bathroom was float and set, but not 100% sure on this room as I only got one photo at end of day and didn't see the tiler in action here.

https://drive.google.com/file/d/1rbWwFj4UladnbI3aDlhF8S4l5DGGN_Gd/view?usp=sharing

The grout was Mapei flexi, adhesive was Mapei Keraflex Maxi S1. As far as I am aware, the boards were fitted with Gyproc Driwall adhesive.

Due to lack of completion on other snagging works, I am not expecting the original builder to make good on this and they are no longer responding to queries and requests, but we still have the retainer so won’t be out of pocket (hopefully). Any advice on the first point in particular would be helpful as I don't want to retile it for the same thing to happen again. But also keen to know if/how the two issues are connected.

Our main bathroom is totally fine, it's just the shower area in the en suite.

 

[TeaAndBiscuits]

Tiled straight onto untanked plywood in a wet area?

How long ago was this done? Plywood on the walls in a shower was never a good idea but is actually against the British Standard since middle of 2018.

Hard to tell from the picture but if it's not bare plywood then it looks like it's been plastered. Still needs tanking if so but was it at least primed with SBR/acrylic primer before tiling? It doesn't look like it. Cementitious adhesive won't bond properly to gypsum plaster.

Either way, the whole lot needs to come out, everything dried out, tanked properly and retiled.

Probably goes without saying but you must cease use of this shower until rectified unless you want a sheet of tiles falling on your bare feet.

 

[TeaAndBiscuits]

With respect to the first point (the crack) - does the plywood butt up to the wall/pillar? If so then any movement in the board - and it doesn't look like it has a lot of backing framework to it - will be concentrated at that joint.

It would be better for the substrate to go the full width of the tiling, have more substantial support structure behind it and go right across the face of the pillar up to the adjacent wall.

 

[CRB81]

Tiled straight onto untanked plywood in a wet area?

How long ago was this done? Plywood on the walls in a shower was never a good idea but is actually against the British Standard since middle of 2018.

Having had a look from the back (I can remove the shelf backing onto it from our bathroom) I think it might have been tiled onto the ply on one wall. It was done in mid-2018 (I drafted my post on NYE so the reference to last year is out of date).

With respect to the first point (the crack) - does the plywood butt up to the wall/pillar? If so then any movement in the board - and it doesn't look like it has a lot of backing framework to it - will be concentrated at that joint.

Hard to tell conclusively until the tiles come down, but my hunch is that the ply does butt up to the wall as movement is likely in that area and would be in keeping with the cracks.

When we get the tiles taken off I will look out for that and make sure the substrate covers the full width of the wall as a minimum, as well as improving the support structure behind it.

 

[TeaAndBiscuits]

In the picture where you can see the floor - what's going on with the grout? Has it broken up and fallen out?

 

[CRB81]

In the picture where you can see the floor - what's going on with the grout? Has it broken up and fallen out?

No, the grout is all in place everywhere. None of it has broken up at all.

In the photo with the edging trim (and floor), the bottom row of tiles on the left-hand wall are starting to buckle out for the ground upwards, while on the right the tiles have come away from the wall like a single sheet.

There is definitely an issue with the tiles and wall, but it looks like it has been exacerbated by some movement in different parts of the room too.

 

[TeaAndBiscuits]

Yeah I see that, I mean the grout between the floor tiles

 

[foxhole]

Looks a bodge job. [Small tiles mean lots of grout for water to penetrate.]