Advice needed for dealing with damp/mould issues

[AngeloMysterioso]

Posting here as advised in another thread I started in Chat. This will be quite long as I want to include as much relevant info as I can; going to bullet point things for ease.

• I live in a small, 2 bedroom ground floor flat at the bottom of a pretty steep hill, with my husband and 22mo DS. Currently pregnant with 2nd DC due early December.

• The building I live in was built around 1910. It is now four flats but it’s such an odd shape that I really don’t think it was originally intended to be residential (have added floor plan).

• There is a small lawn in the garden which sits about a foot higher than the bottom of the building at one end, on a slope so it gets higher further back. There are air bricks around the base of the building.

• We moved in in December 2019- our neighbour in the other downstairs flat moved in summer 2019. We both had the usual surveys done and neither came up with any current or potential damp issues.

• We had the extractor fan in the bathroom disconnected in April last year. This was necessary as it had been wired alongside our electric shower in such a way that it presented a serious safety risk. Until recently the bathroom window was always opened after every bath/shower (I say until recently because it’s now open pretty much all the time). Bathroom door has always been kept closed at all times. We have yet to have the extractor re-installed, purely for financial reasons but it is top of our to-do list and will hopefully be done before DC2 is born if we can afford it.

• Due to the odd shape of the building, our bedroom has three external walls. The only internal wall is largely occupied by a fireplace which we intend to have professionally sealed (also on the to-do list). We have very tall wardrobes against one of these external walls, which we have had to fix to the wall at the top for stability, so they can’t be moved (have added floor plan for this too, furniture positions drawn in red).

• Because the flat is so small, space and storage is an issue and we have things in every nook and cranny- as well as the large wardrobes we have under-bed drawers, things tucked under the changing table and cot bed in DS’s room, cupboard under the stairs is full to bursting etc. We have looked into storage but it is just too expensive at this time.

• Last October we began to find things going mouldy; to start with it was the boots and shoes that are kept on shoe shelves in the bottom of my wardrobe. Then clothes in the under-bed drawers. Last week found mould on things kept in DS’s room and around the frame of his cot bed. So far we haven’t had any issues in the sitting room, bathroom or kitchen. So far there are no signs of mould on the walls. I have washed/scrubbed everything with copious amounts of white vinegar and sprayed the carpets under the bed and DS’s cot bed.

• Our neighbour in the other downstairs flat says she also has a mould problem- in her case it actually is on the walls, and she has redecorated with mould resistant paint.

• We do not have a tumble dryer, there is no space for one and we can’t afford a washer-dryer. We have dried clothes outside when the weather has allowed and quite often take a few loads up to the launderette but this is quite expensive so we have largely been drying clothes around radiators. I have recently bought a large heated airer with a cover and plan to use this, with the de-humidifier running beneath it, instead.

• Ventilation has been an issue- we had very old, single-glazed wooden sash windows, the frames were in very poor condition with all manner of insects living in them so they were opened rarely. We have just had new UPVC sash windows installed so that will no longer be the case. The new windows do not currently have trickle vents, we have spoken to the fitter about this who is going to contact the manufacturer and see if they are able to be fitted with the type of windows we have. If it’s an option then we’ll be getting them fitted ASAP. Until then we will be opening the windows at least a crack every day. I have also started lifting up the mattress in DS’s cot bed every morning and leaning it against the side to allow more air underneath, and opening the wardrobe doors and drawers for a while each day as well.

• We have also just been given a Meaco Low Energy 20l dehumidifier, which we will be running initially every evening and overnight until we can get humidity to a healthy level- target is 45%. The first night we had it it read 79% in my bedroom- it is now down to 65-70% depending on where we have it in the flat.

• We have also had a slug problem- they are popping up mostly around the sofa and back door in the sitting room, and also between the bed and wardrobes in the bedroom. Not sure if this is related in any way.

So the advice I’m looking for is what other steps I can take to solve or at least mitigate this issue? Finances are currently very stretched and we now have the new windows to pay for so we can’t make any big purchases for at least the next few months, but I am otherwise open to any and all suggestions.

"Drain on the corner of the house by main bedroom window, can’t see any obvious faults with it"

any fault is likely to be below the ground. The metal pipe will connect to a glazed brown clay pipe, or a gulley. These are often cracked and leaking. You might be able to see the top of the gulley at about ground level.

@PigletJohn

"Airbrick at the base of the wall that the back of the wardrobe in my bedroom is against"

there is green moss or algae around here, so it must be long-term damp.

Does the ground slope towards it, causing puddles?

Not that I’ve noticed, the rain doesn’t really collect anywhere

@PigletJohn

"Airbricks at base of sitting room wall. This is where the slugs have popped up"

see if you can scrape away the stone scalpings to see what is underneath. The airbrick is rather close to the ground.

There’s a sheet of sorts underneath the scalpings and then what looks like brick underneath.

@PigletJohn

Between the two doors, where the rainwater downpipe and the soil pipe come down, appears to be a small brick plinth. Can you take some pics around this, please.

is there a dark brown glazed clay gulley inside?

Yep! The bottom of the pipe certainly looks like it’s seen better days.

@PigletJohn

Between the two doors, where the rainwater downpipe and the soil pipe come down, appears to be a small brick plinth. Can you take some pics around this, please.

is there a dark brown glazed clay gulley inside?

Second pic is the drain by my bedroom window

@PigletJohn

"Ok, so airbricks etc- these are the ones under the windows outside our room and DS’s room"

this pic shows a shed or something, with a sloping roof, positioned so that rain falling on the roof will run against the wall, making it wet. Unless it has a gutter that I can't see? Is it your shed?

It is but it’s not right up against the wall, there’s a few inches clearance

Sorry for taking a while to respond, been out most of the afternoon. Will answer a few points-

Why would you block your fireplace??? This is an excellent flow of air.
Mostly because of all the crap that keeps falling down into our bedroom. At the moment there’s a piece of stuff cardboard held in place with some pipe insulation but we still find loads of grit and dust at the foot of our bed.

Run the dehumidifier 24/7
We’ve been keeping the windows open during the day and from what I can gather there’s no point having the dehumidifier on when the windows are open. Would it be more beneficial to keep the windows shut and the dehumidifier on?

this might be a duct for the soil pipe from the WC if I interpret your diagram correctly. Especially if the floor is concrete so it would be too much effort for the builders to dig it up to run to the nearest manhole or underground drain. Is there a manhole outside in that direction?
It’s really obvious now you say that… this is the wall that the washing machine, sink and dishwasher are against in the kitchen and the sink and loo in the bathroom so that’s probably just covering where all the pipes are. There is a manhole cover by the door to flat 2 so they probably lead there.

The extractor fan will make a WORLD of difference. I used to rent a similar building and the mouldy things/damp/slugs were horrendous if the extractor fan wasn’t used regularly.

Can you get that done quickly?
It’s top of the to-do list but we’re a bit stretched after the windows, and the car MOT costing way more than we’d anticipated so it may be a little while yet before we’re able to get it sorted.

Are these all wooden floors?
Yep. Quite uneven in places.

Do you have a water-meter?
I believe so but not sure where, will have a look around this evening.

@PigletJohn

the bathroom extractor will typically have a 4"/100mm diameter plastic duct going through the wall, with a plastic vent outside. Does yours?

Is the fan above the bath? If so, how high above the floor?

How far is it from the ceiling light fitting?

Sorry, thought I’d added this pic earlier. As you can see it’s right below the ceiling, which is just over 2.5 metres from the floor, maybe allow 10cms for the bath?

(the fan) " As you can see it’s right below the ceiling, which is just over 2.5 metres from the floor, "

that's high enough. Its more than the minimum required for a fan above a fixed bath or shower (electrical rule) so you're OK to put a new one in the same place. i suspect the cable runs in the ceiling, which will be awkward unless the person above lets you take ther floor up (unlikely). But you could run it in white minitrunking from the (lighting) ceiling rose which is not too bad. Can you see a makers name or logo on it?

It’s an Xpelair one- I don’t think the issue was the location of the fan itself but the box where it was wired in, which is right next to the shower (the cord you can see is for the shower but also turned on the extractor, which I think was also part of the problem). It needs to be moved, re-wired and the ceiling replastered. At least that’s what I understand but I may be wrong!

the brown glazed clay gullies are usually always cracked and leaking in old houses. The brick surround is probably an attempt to prevent water leaking out from the cracks onto the paving. The paving itself may be cracked or sunken, depending when it was last "repaired." I think there is some green algae or moss growing due to the long-term damp. look out for bigger weeds, especially wild tomato plants, which are a very bad sign.

The gullies would originally have been at ground level when the house was built. If they are now lower, either they have sunk (due to a leak washng the soil away) or the paving has been raised (which is likely to bridge the damp proof course). Or both. If you look at the walls close to the doorstep, you may find a wider mortar joint, with a bed of slate in it. This will be nine inches (two bricks) above where ground level used to be when the house was built. Once you find it, it is pretty certain to be at the same height all round the house. Slate lasts at least 250million years, so the dpc will not fail, but is often bridged by render or paving.

if you are able to take up floorboards on the inside of the adjacent wall, I think you will probably find a damp patch arising from the leaky drain. I think it will be a home to the slugs. This is very common. It needs to be dug out and replaced with new. Sorry.

Clean out all the airbricks as much as you can. They may be clogged with a hundred years of cobwebs and dust. The more airflow you can get, the more damp air will blow away rather than rising into your house. The slate DPC might be visible on the interior of the walls when you look under the floorboards.

An extractor fan can be fed from a shower circuit. It needs to be fused down (3Amp is usual) with an FCU. If it is as far above floor level as the fan, this is permitted, though if it is in a place liable to be squirted or sprayed, it would have to one be rated against water penetration. This is not difficult, they are sold for outdoor lighting, fishponds, etc.

you mention rubbish falling down the fireplace. I would not worry about this much, unless rain runs down as well. When funds permit, you can have a chimneysweep in to sweep it. you can block it with any convenient board. Ply would do. Cut a brick-sized hole in it, and you can fit a plastic (or brass) vent in it with a gauze screen (intended as a flyscreen but will keep grit out). Even if bricked up, flues must always be ventilated top and bottom or they will become damp.

To block a fireplace you first screw battens to the sides, top and bottom of the opening. If you are not an ace DIYer, start a new question about that, or this thread will get too long and complex. Neither men nor women are born with DIY skills so you are not expected to know it all.

does the extractor fan look like this one? Note the wavy lines.

or this one? with straight lines.

it is not as powerful as I would like, but you can run it continously if the room is damp.

If it is noisy, I can suggest a much quieter one (also a little more powerful) that will fit into the same 100mm hole. Neighbours may grumble if their bedroom is above, but not usually for a bathroom.

"It is but it’s not right up against the wall, there’s a few inches clearance"

you must must must must fit a gutter or turn it round. Water will cascade off that roof onto your wall.

@PigletJohn

does the extractor fan look like this one? Note the wavy lines.

or this one? with straight lines.

it is not as powerful as I would like, but you can run it continously if the room is damp.

If it is noisy, I can suggest a much quieter one (also a little more powerful) that will fit into the same 100mm hole. Neighbours may grumble if their bedroom is above, but not usually for a bathroom.

I’ve taken some pics, the sticker on the fan says the model is 90847AW, and on the wiring box thing it says LV100T.

@PigletJohn

"It is but it’s not right up against the wall, there’s a few inches clearance"

you must must must must fit a gutter or turn it round. Water will cascade off that roof onto your wall.

Can’t turn it around because then the doors would be against the wall but I could have a go at fitting a gutter on if that’s not too complicated a task? I might just move it to be honest, it’s not really a proper shed, it isn’t even fixed to the ground. It’s essentially an overturned wooden box. We’ve got a planter by the fence we could get rid of and put it there.

I’ve just found the email we sent to the other flat owners re shower/extractor-

I’ve just had an electrician in as my shower pull cord had stopped working and he found a bit of wiring that could have potentially started a fire. The extractor fan was wired into the same switch and the current was far too high for those components, as well as the transfer box for the fan being in the immediate vicinity of the shower, which is another hazard in itself.

Don’t know if that helps at all!

oh, it's a safe-extra-low-voltage 12v fan.

the box on the ceiling must be the transformer.

what a shame your electrician didn't know how to fuse down an appliance on a radial circuit.

@PigletJohn

oh, it's a safe-extra-low-voltage 12v fan.

the box on the ceiling must be the transformer.

what a shame your electrician didn't know how to fuse down an appliance on a radial circuit.

Is that a difficult thing to do? And is that extractor powerful enough?

Thanks so much for all your advice by the way, I really do appreciate it and will be carrying out as much I can as soon as I’m able!

I think you need a different electrician

the switch and the connector/transformer would be best moved further away from the shower to remove the risk of accidental squirting or splashing.

The position of the fan does not need to be SELV so IMO that is an unnecessary complication.

The fan looks black with dirt. If you do decide to change it, ask your (new) electrician if an Envirovent Silent 100T would be suitable. It is a mains voltage fan so the transformer box would not be needed. Tell him the height of the fan above the floor, and that it is IP45 rated .

This is a very good and quiet fan, often available for around £35. It is a rebrand of the Soler & Palau (same group) which is usually more expensive, and a top brand.

You could have a much more powerful fan if you had a 150mm duct through the wall, but I think yours will only be 100mm. Having a larger hole bored would cost extra.

A 100mm fan needs to be run for longer to clear the steam. The Silent 100 is, IIRC, about 25% more powerful than the Xpelair, and noticably quieter. (better motor design) It uses fractionally less electricity