In despair over very damp wall following a bathroom 'accident' - what to do for the best??

[GlomOfNit]

We live in an ex-council house c. 1920, single skin brick walls (i.e. cold external walls in winter) and while it has its pluses, I'm fed up with all the negatives that we can't really afford to fix (roof needs redoing, render, crap plastic framed windows put in by someone who was bad at it, etc). We're rubbish at maintenance.

My most pressing issue is one of my own making. The 'family' bathroom is downstairs, off a little vestibule leading from the kitchen. I hate this room - it used to be the toolshed or something, from a time when council houses didn't have plumbed in bathrooms (or so I've been told). It's cold and cramped. The bath backs onto an internal wall, the other side of which is the living room. A sofa is up against that wall.

My lovely lovely son (who has severe autism and LDs) fiddled around with the screw in the middle of the overflow outlet of the bath (the screw is in the middle of the grille that then takes overflowing water from the bath into a pipe). For ages and ages we just registered that the grille was 'a bit loose' and in my normal slapdash way I mentally shelved finding another screw and tightening it. But in fact, what was really happening was, the sodding overflow pipe was no longer connected properly to the grille and water was sloshing down through the overflow hole and lots was going down the back of the bath cavity. My own stupid fault, I should have sorted this out much more promptly.

I was alerted to this when I realised I could smell damp plaster in the living room. I pulled back the sofa to see a sight that would grace any decent dungeon - different types of mould and obviously sopping wet plaster.

We got in a plumber and annoyingly I wasn't in the house when he was here so didn't have a look myself but he apparently said it didn't look too bad under the bath and that now the water ingress was fixed, the plaster would dry out itself in time.

Meanwhile, I'd purchased a decent dehumidifier (this is a damp house anyway, all these ones along this road are and I know most people have issues that they fight with) and pointed it at the wet wall. Initially it was taking lots of water out but I'm not sure it's really making much difference now. I assume there's only so much a dehumidifier can do. I've also been pointing an electric fan heater (££s!) at the wall in between times to try and dry it out. The radiator in the living room is the other side of the room and it's not on that much at the moment because of fuel costs. We do have a woodburner (also about 6 metres away from the wet wall) but it's actually been too mild to have on! The dehumidifier has been on for a few hours most days over 3 weeks and the fan heater maybe for the last week?

The plaster is mostly sound I think though some parts sound hollow. I've torn away the painted-over lining paper that previous house owners covered the walls with, to allow the plaster to breathe and dry out. Which is obviously unsightly.

I'm just in despair though. I feel like this is something I need someone in to help with but I don't even know what sort of tradesman would be able to help. I'm wondering if the bath issue really is fixed, I'm wondering if there's another damp issue that the bath thing is masking. The room smells damp (particularly when the fan heater is blasting hot damp plaster smell everywhere!) and it's really depressing me.

And obviously budget is an issue (particularly this time of year when spending is higher, not to mention fuel costs) but if we have to get someone in to fix this, we will. Who do I try and get in? Or should I keep going with the dehumidifier/fan heater?

(I hope I've managed to attach three images - the 'worst' are what was revealed when I realised the problem and the third is of the current situation.)

Hi - no I really think it was. When we investigated, it wasn't 'a bit loose', the bloody pipe that's meant to take the overflow water away was no longer connected to the grille/overflow hole on the bath, so any sloshy water (and he does slosh around!) was sloshing through the unprotected hole in the bath and thence into the space under the bath.

I think it was happening over summer. Since I smelt wet plaster in the living room has been 3/4 weeks, we got the dehumidifier into the living room and working 3 weeks ago.

I think the silicone seal is ok, it's a bit mildewed the way they can go but seems sound. But I'll recheck. Grouting appears sound.

Bath panel is off. It was soaking wet (we could see it had swollen). Fan heater directed at the under-space at the moment.

Thanks for telling it like it is. This is what I'm terrified of and I really am aware we're crap at maintenance, so I'm aware of our need to be on top of this.

As another poster suggested, I think we'll have to get in an expert, a damp specialist. Oh god ££££ but I don't know what else to do really. I'll continue with the suggestions from this thread, including checking all the pipework for leaks - though there was horrible mould on that wall AFTER the overflow hole stopped feeding into the pipe but BEFORE the plumber came to fix the overflow, I'm wondering if he jogged a pipe join somewhere and worsened a slow leak?? I mean, professional plumber so he probably didn't, but that would have been the first time someone had the side of the bath off for about 4 years (since we had the new side put on).

Right now, I have the dehumidifier going in the living room (windows closed!), sofa pulled away obviously (and I think we'll have to work out how to relocate it away from that wall for this winter) and a fan heater pointed under the bath. Windows are almost always cracked open in that horrible bathroom because of condensation (yes, there's an extractor fan too!).

I'm pretty hot on cracking open windows year round unless it's raining heavily for ventilation, plus most windows have those slidey vents you can open, at the top.

Thank you all for the support and advice here.

A fan will be much cheaper to run than a fan heater, and possibly as effective. Can you ask around?

Ha - we literally just put our two hot weather fans up in the loft! 😂

Try posting this in DIY, @pigletjohn Is the mnetter you need.

Update of a sort

Thank you thank you everyone who's suggested doing more detective work, or that it couldn't possibly JUST be the wonky overflow, etc.

So as of this morning, the side is off the bath. It's pretty yucky (all swollen up - this can happen eventually just from splashing down the side when the sealant goes, but I'm sure it's damp because of this current issue). Underneath is a concrete floor, some of which has been drilled away to accommodate pipework. God knows how sound it all is.

I looked at the back wall, the wall in question. Some of it is tiled (behind the bath, which will be covered by the bath side) and where this ends, below the last tile is clearly wet plaster and there are little runnels sort of carved into the plaster by, I assume, water. I dried everything off with kitchen roll, the fan heater had dried pipes if they were wet in the first place anyway - and I put the hot tap on to see if I could tell if that made any leaks start up along pipe joins etc. Couldn't see anything obvious. BUT I did watch a drip form on the underside of the fibreglass bath, right by the tap. It's possible that the tap has a leak or loose join where it goes into the fibreglass of the bath - but higher up above the taps is the electric shower unit and there, ladies (and gentlemen?) I think we have our culprit. There is a steady leak from the bottom of the shower unit. It's not a drip drip leak, it's a gentle seep and since there's so much condensation in there and I'm mostly in there after the boys have had a bath or shower, I've not noticed.

So whatever else is going on, I think the sodding shower has a leak and that since it's constant, it may well have found a vulnerable place in the bath sealant and has been seeping through.

For those who were saying it can't be the overflow, I think it was definitely part of the original problem as the actual overflow pipe was no longer attached to the hole in the bath! (I believe. Like I say, I couldn't be in the house when the plumber was here, and DH never asks the right questions.)

Further horrible pics to illustrate!

Thank you, I'm going to get a BETTER plumber to sort out the shower leak, sort out the sealant and then possibly a damp person.

(First three pics - bath with the side off. Underside of the bath <shudder> . Plaster below the tiles, which is normally hidden behind bath.)

As this looks like being a big job to dry out the wall thoroughly especially if you have to remove the plaster as well, could you go through your insurance company?

and finally the accursed shower unit, and the SEEP from underneath it. I'm sure this is all fascinating for you all. 😉

Right, well that's excellent news in that you've identified the culprit.

I'd consider ringing the first plumber and asking if he'll help at a reduced rate, as he failed to notice the actual cause- people here who couldn't even see it were surprised that an overflow would cause the amount of damage you were dealing with. He should have looked further, IMO.

Have you got insurance? Ring and ask what the deal is. It may be part of your house insurance, or if you have an emergency repair scheme covering your boiler.

@pigletjohn may be able to advise if there's an easy way to turn off the water supply to the shower in the short term.

Glad you are getting there.
I wouldn't get a damp specialist as most of them seem to be clueless or trying it on.
Amazing how many trades people can't easily identify where water is coming from and how to fix it.
Hope you get it sorted now and give it time to dry out once all leaks solved.
At most I would hire the industrial dehumidifiers myself.

@validnumber That’s sad that you are so cynical of damp specialists, you obviously have had a bad experience, fortunately I had a good experience earlier this year and he certainly wasn’t clueless or trying it on and rectified a bad damp problem in the property. But everyone is entitled to their opinion of course.

• you may be able to claim this on your home insurance. Tricky as the damage has been caused by your son, but if he has LD/Autism this may be taken into account. Certainly worth a phone call.