Wall showing damp from shower area - tell me the worst!

CotswoldsRetreat · Post by **CotswoldsRetreat** » Wed Sep 06, 2023 3:03 pm

Hi all

I have a feeling anyone replying to this request for advice is going to tell me it's bad news....but I ned to have it confirmed.

I've attached some photo's of a wall showing signs of water leakage from the shower that is on the other side of the wall in the bathroom. It started just a few short months ago but has accelerated the last month or so.

You can see patterns of damp and paint that has started to bubble up. You might be able to notice that the area affected is in the shape of a small doorway, that's because there used to be a door to a storage cupboard and has been filled in when the bathroom was enlarged. I can't tell from hitting it with my knuckles whether the doorway was filled in with brick or plasterboard or something else. It probably doesn't matter as water is getting through from the shower in any case.

The bathroom was refitted 3 years ago with a bath and electric shower removed and a walk-in shower installed and a shower linked to a gas boiler installed. The mixer tap in the shower is roughly in line with the plug socket on the left and up just below the larger picture frame. Curiously that is not where I can see any dampness, so my thinking is that water is seeping into the grouting and/or any cracks in the grouting. The water then follows the grooves of the tile adhesive and spreads outwards in various directions.

Crucially, having done some searching of UH videos on how to install bathrooms, I don't think the shower area was tanked before being tiled. I believe the tiles went straight onto plaster.

So, what's to be done? It looks to me like the shower unit and tiles will on need to come off and...well...I think the shower project needs to start all over again. There's not just the wall that the shower mixer is on but the left hand wall within the shower unit could be affected and all those tiles remove too (the other 2 sides are all glass panels). As you stand in the shower until facing the mixer tap the wall to the left backs onto a bedroom and although I can't see evidence of dampness on that side it is only a matter of time.
I also expect that the affected wall that you see in the photo's will need repairing but I'm not sure what would need to be done though removing existing plaster and re-plastering will be required.

I'd appreciate some advice on best plan of attack on this before it gets worse. I've dabbled in DIY and prepared to have a go at whatever is required though I've not done anything remotely as difficult as this.

Many thanks in advance for any pointers submitted.

Cheers, Ian.

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CotswoldsRetreat · Post by **CotswoldsRetreat** » Wed Sep 06, 2023 3:04 pm

Sorry about the photo's being the wrong orientation and one being out of focus!

dewaltdisney · Post by **dewaltdisney** » Wed Sep 06, 2023 4:38 pm

My first thought was this a pipe leak on the valve, is it built in or a surface mount? If built in it could be just the outlet pipe joints that leaks when the shower is on. Water will find its way down and it looks like the pattern is following a pipe run. Is it possible to take the valve fascia off to check the joints? It is unlikely to be tile joints and if the wall to tray seal was breached the water stains would have a different pattern. Water might creep in a pinhole but it would be too low a volume to cause that.

I had a shower once that had tiles on ply and when I ripped it out the only rot was at the tray to wall. The tiles had all held on the ply. So do not despair, it might be a simple joint tightening to solve the problem. You may have to run the shower and check around the valve for any water on the pipes.

DWD

CotswoldsRetreat · Post by **CotswoldsRetreat** » Wed Sep 06, 2023 8:00 pm

dewaltdisney wrote: ↑Wed Sep 06, 2023 4:38 pm My first thought was this a pipe leak on the valve, is it built in or a surface mount? If built in it could be just the outlet pipe joints that leaks when the shower is on. Water will find its way down and it looks like the pattern is following a pipe run. Is it possible to take the valve fascia off to check the joints? It is unlikely to be tile joints and if the wall to tray seal was breached the water stains would have a different pattern. Water might creep in a pinhole but it would be too low a volume to cause that.

I had a shower once that had tiles on ply and when I ripped it out the only rot was at the tray to wall. The tiles had all held on the ply. So do not despair, it might be a simple joint tightening to solve the problem. You may have to run the shower and check around the valve for any water on the pipes.

DWD

Hi DWD and many thanks for your reply.

I'm not sure what you mean by "pipe leak on the valve" and "..is it built in or a surface mount". But...
...the hot and cold pipes in the bathroom run under the floor from outside the shower unit (they've been cemented over) and then run up the wall (but again have been covered over). The hot and cold outlets are poking out of the tiles to which the mixer tap is connected. So the hot and cold pipes are running vertical but the dampness and bubbling are not following the pipes.

If these hot and cold outlets are leaking then I think I would have to remove tiles and disturb the plasterwork to check.

I can see the mixer tap connected to the hot and cold outlets but there is no obvious leak that I can see. The outlets would subsequently connect to the pipes that run vertically but because they are recessed within the wall I have no way of checking them. I've always wondered how you can check pipes if they are embedded within a wall and there is a leak.

I've had a close look within the shower unit and have spotted a crack in some grouting near the shower base. I think the lowest level of tiles has come forward at the top of the tile where it meets the tile above, probably due to movement caused by standing on the shower base (there is slight bit of flex of the base as it is not made from a hard material like porcelain or whatever they are made of). But if water is getting in here it wouldn't explain the dampness much higher up where it first started.

Any further thoughts? :) Thanks again.

dewaltdisney · Post by **dewaltdisney** » Thu Sep 07, 2023 7:05 am

If the hot and cold feeds come out the wall then the valve is exposed. I was thinking if the valve was built in (in the wall) this could cause the issue but that sounds like it is not the case. I take it the shower head is on a hose or an external pipe? The wall bubbling would indicate a leak higher rather than by the tray and a lower leak would have shown up in the ceiling below by now. This is different from rising damp, rising damp is where the saturation of bricks is caused by moisture rising by being drawn upwards from a breached damp course and building upwards. In this instance, any water would be soaked up by adjacent bricks and gradually permeate downwards. It is a strange situation hard to fathom remotely. Rather than pull it all out can you trace a pattern on the exposed wall with a damp meter (if you can lay your hands on one or £20 on Amazon) to give you a greater understanding?

DWD

CotswoldsRetreat · Post by **CotswoldsRetreat** » Thu Sep 07, 2023 9:59 am

dewaltdisney wrote: ↑Thu Sep 07, 2023 7:05 am If the hot and cold feeds come out the wall then the valve is exposed. I was thinking if the valve was built in (in the wall) this could cause the issue but that sounds like it is not the case. I take it the shower head is on a hose or an external pipe? The wall bubbling would indicate a leak higher rather than by the tray and a lower leak would have shown up in the ceiling below by now. This is different from rising damp, rising damp is where the saturation of bricks is caused by moisture rising by being drawn upwards from a breached damp course and building upwards. In this instance, any water would be soaked up by adjacent bricks and gradually permeate downwards. It is a strange situation hard to fathom remotely. Rather than pull it all out can you trace a pattern on the exposed wall with a damp meter (if you can lay your hands on one or £20 on Amazon) to give you a greater understanding?

DWD

Hi again DWD

Ah, the hot and cold valves are recessed into the wall and there are two S connectors into those and the mixer tap then screwed into the S connectors. No obvious signs of leakage at that point.

So, this suggests a possible leak where the hot and cold valves then connect to the their respective pipes which run up the wall vertically. Whether there is a leak at these points or not they only way I could check is to expose these joints but they are within the wall. Other than removing tiles and chipping away at the plaster I can't see how I would can find out if there is a leak.

The mixer tap has an outlet for an overhead shower head and a lower hose for a shower head you can hold. What you write about rising damp makes sense - the areas of dampness have created a pattern which shows the previous existence of a door and they are all below where the mixer tap would be on the other side of the wall within the shower unit.

I'll have a look at a damp meter in due course. Thanks again.