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.)

I think your dehumidifier is too small particularly if your house is also damp in cooler weather.

When a friend of mine, who lives in a Victorian house, had to dry out a damp floor he used an industrial dehumidifier for 3 weeks that was on constantly. This meant that it could cope with normal day-to-day living plus the extra job of drying out the floor. Your dehumidifier is like one I have to help dry my washing.

Added to that when I had to dry out a plaster room last October/November I used an infra-red heater plus left my windows open all the time. The infra-red heater was on for about 8 hours per day. The room dried out in about 10 days.

Oh dear, that's all very stressful.

If you're not convinced the damp problem is fixed you would need someone to look for it otherwise it'll just stay there but really if the bath caused it and has been fixed it should be OK.

Have you tried a mould spray? It'll make the wall slightly damper but should get rid of the mould and the smell. The HG one is very good.

If budget is an issue I'd spray it and keep going with the dehumidifier.

Quick note to say that you can rent industrial style dehumidifiers \ heaters (Jewsons do tool hire here). Not cheap but it gets you access to decent kit to help get it completely dry. I had a similar issue with a back wall (leak from outside) and took 3 days of infradred heater/dehumidifier to dry.

Oh god, you think? It was the £150 Meaco one, it can take up to 10l in 24 hours (obviously you have to change the container several times!). I'd thought it would be ok, though I know I'll need to move it round the house to 'do' different areas. I've had it on the landing when we have damp towels over the bannisters, for instance.

I was also thinking about those heaters that builders use to dry out new plaster. Thing is, something like that or a huge industrial dehumidifier aren't really a starter here, because of DS (the autistic one who fiddled with the bath overflow in the first place). He fiddles with everything and anything bulky and obviously new to him would be a massive magnet. And unsafe, because electrical.

Who (what sort of tradesperson) do you think we should consult then? I'm clueless about this. DH just said 'oh a builder' but I'm not so sure. I suppose the firs thing to do is prise out the bath panel again and see what it looks like now. And maybe leave it off a while so it can dry out from both sides. Which will entail an issue with DS who will want it back to normal, but we'll just have to cope with that.

I do swear by HG mould spray! So do lots of my neighbours by the sound of it. I initially used it to get rid of the mould and mildew on the wall (painted lining paper) and will lightly mist the plaster now it's exposed.

Thanks - we'll consider this option if our current regime doesn't bear fruit soon. I'm very reluctant to get in anything bulky and interesting looking, because of DS's obsession with electrical items and undoing things.

My concern is the bath side of the wall. If you've put the panel back then how is it supposed to dry out? You can't really dry a soaked wall from one side, it needs to be both sides.

I have a damp house in autumn. I have to put the heating on for 20 minutes a day as using a dehumidifier alone is not enough. 20 mins is enough to warm the air slightly so the dehumidifier can pull out the damp better.

I’d suggest cutting a hole in the wall and putting in a grating. It’ll make the whole process go much more quickly.

I would probably cut out about a sqm of plasterboard and let the wall dry properly and then fit a new piece of plasterboard, fill in the gaps, paint etc. Also, with regards to the dehumidifier, it should be in an enclosed space to work the best, so having it on a landing is not optimising its use. If you use it in the lounge, then make sure to close all the doors/windows to let it do its work.

I would take off the bath panel and move the dehumidifier into the bathroom for part of the day. I flooded my bathroom once and the water went through the wall into my bedroom, the concrete floors were sodden and took weeks to dry out, but the walls/plaster board were much quicker. I had a dehumidifier very similar to yours, I also used some of the crystals type mould collectors (which were much cheaper.

Is there a concrete floor at all? Wet concrete can smell very musty!

I would:
Take the bath panel off
Shut as many doors as possible around the affected rooms.
Dehumidifier going 24 hours a day - you could put it in the bathroom while DS is awake, and livingroom overnight, or some other split?

Does DS splash a lot in the bath? We rarely have water going down the overflow. I wonder if you can get a casing for the overflow that would reduce splashes, but still allow for it to act as an overflow when actually required?

The overflow was unscrewed. Hopefully it’s screwed back into place now.

How long has it been?
Things like this are taking ages to dry out at the moment due to the weather.
Remove the bath panel and double check everything is fixed. To do this put kitchen roll down everywhere under the bath or wrapped around the pipes to check no new or other leaks.
How's your side seal around the top of the bath? Could water be getting through here? How's the tile grouting?
Good idea to remove the bath panel overnight and leave the dehumidifier on in their of a night. Also good idea when it's in the living room to close the door so it can focus on that area.

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

I have no idea about your damp problem but we're exactly like this too about house things. Ignore them and hope they magically fix themselves, but they never do. They just get worse.

I hope you get it sorted op.

I think I would start with an experienced old school plumber to make absolutely sure the problem is definitely fixed.

Then tackle the rest of the it.

This is not going to resolve with a little humidifier at this time of year. All your joists, flooring and wooden battens will be soaked, and you can't see them. The plaster needs completely removing, all what is behind needs checking for damage (if the wood is left wet it will rot and then you will have a far worse problem). Then if nothing needs replacing it needs drying out properly and then replastering.
I appreciate you are struggling to do things with your son's needs taken into consideration, but leaving things and hoping for the best is why you are in this situation in the first place. If your property is not kept in good condition your house insurance will be invalid and if you have a mortgage and they come to do a revaluation, they may not renew it.

I was going to say the same as @DelilahBucket . Sorry OP :(

You don't say how long you have been going with the dehumidifier so maybe it would be possible to clear it up with that.

I had a problem equally as bad, worse really, caused by loose guttering and the house had been empty for moths o it was really bad. I used a dehumidifier only - about the size of yours, plus mould spray, then a repaint with some specialist paint. Summer helped, then the problem came back a bit in the winter, but is now gone. I considered myself very lucky to get away with not hacking plaster off.

Oh and just to say, good ventilation is everything- you can't have the sofa up against the wall really, air has to circulate and windows open on dry days.

I'd get a plumber in again. It seems highly unlikely to me that the damp was caused by the overflow. The loose screw wouldn't have made any difference to the function and do you all regularly fill the bath to overflowing?!

I had black mould in a new build, due to inadequate ventilation. It cleared quite fast once we emptied the area.

I wouldn't give up just yet. Open up the bath, as a PP says, run the dehydrator 24/7 alternating sides of the wall if you can.
Maybe open the bathroom window when the dehumidifier isn't in there. Otherwise keep the doors shut so it can work.

Have you got any fans? Could you borrow one? A fan on one side, dehumidifier on the other, perhaps.

Hi OP, sorry to hear you’re having this problem, I would suggest looking for a damp specialist in your area. They can locate where the damp is coming from and going to and have specialist treatments that they can use. I used one last year and his company was fantastic and didn’t even charge for an initial assessment or report. Good luck.

Have you treated it with bleach or mould spray?

our wood burn in stove heats the room really well. Do you pay for logs? If not I’d have this going daily plus it draws air up the chimney so good circulation. then run dehumidifier the rest of the time. You could buy smokeless fuel if it’s a multi fuel stove.
I think you need to keep air flowing in the bathroom so open window when not using humidifier.
you could visit a plumbing / builders supplier ( I mean the ones that local plumbers use - not Wykes etc) and ask their advice - they can be knowledgeable.

Unless you have been emptying your bath out via the overflow (rather than the plug), even the splahiest of kids shouldn't have caused that much water to go through the pipe, even if it was completely missing never mind not screwed in fully.

Do you have any other (even external) pipes in the area or above? I have a damp area in my bathroom due to shit ventilation but given a good clean and some spray (plus some anti-mould treatment and paint) plus keeping the WI Dow open it has cleared. Sodden plaster is not just from splashing water at a loose overflow.