Mould in houses

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francovendee
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Mould in houses

Post by francovendee »

The subject of mould in houses is mentioned frequently after the sad death of a child.
I wonder if anyone here has problems with mouldy houses?

We have an old stone house with exposed stone on one wall. When we get days of heavy rain we can get a black mould form at the base of the wall. we can't stop the damp in this wall but control it by spraying with a fungicide.

I expect in other houses with DPC's that have mould, it's because of moist air meeting cold walls. The answer may be more ventillation but with the high cost of heating this isn't followed.

Of course defects in the roof, windows or pointing can be causes but if these are in good condition then is it down to lifestyle.

What set me thinking about this is a friends house that was his home but is now rented out. He'd lived there with his first wife and never had mould problems. I know the property is in good order. His tenant is now insisting the house is damp and mould is forming on the walls.
He's getting someone in to take a look but suspects it is the result of drying washing in the house and not opening windows.
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simonineaston
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Re: Mould in houses

Post by simonineaston »

A vexed Q especially for renters. Although we've agreed (on another recent thread), that the physics of the interaction between humid air and cold surfaces is fairly straightforward, we've also speculated that the poorer you are, and for one reason and another, the harder it gets to control the variables.
ps it would be interesting to delve into the influence on damp & mould that renting has...
S
(on the look out for Armageddon, on board a Brompton nano & ever-changing Moultons)
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Mick F
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Re: Mould in houses

Post by Mick F »

Here's a photo of the south-western lower corner of our bedroom. March of this year.
There was a piece of furniture there, so it was out of sight. It was only when I redecorated the room that I found it.
Mould-killer sorted it, and new emulsion paint. We keep that corner clear now.
IMG_1054.jpg
Mick F. Cornwall
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simonineaston
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Re: Mould in houses

Post by simonineaston »

I'm guessing ground floor? I had a lot of trouble in my ground floor bathroom on the sw corner of my Edwardian era brick built dwelling here in Bristol. No dpc. Dry-lined it in the end and That Was A Bingo ! The habit of opening the adjacent back door prior to entering the bathroom persisted even after the arrival of the dry-lining and extra big extractor fan!
S
(on the look out for Armageddon, on board a Brompton nano & ever-changing Moultons)
francovendee
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Re: Mould in houses

Post by francovendee »

I think Mick's post highlights a thing we found here. When we had a cupboard in front of our stone wall it was a much bigger spread of mould. Treating the wall and removing the cupboard had made a big difference.
Now if I was renting the house out I guess this wouldn't be an acceptable solution and I'd have to dryline this feature wall.
peetee
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Re: Mould in houses

Post by peetee »

Mick F wrote: 25 Nov 2022, 9:37am Here's a photo of the south-western lower corner of our bedroom. March of this year.
There was a piece of furniture there, so it was out of sight. It was only when I redecorated the room that I found it.
Mould-killer sorted it, and new emulsion paint. We keep that corner clear now.

IMG_1054.jpg
This is exactly the sort of issue I get in my house, despite using a dehumidifier. Such a device does make a big contribution to keeping exposed surfaces dry and makes the place much more comfortable to be in but it doesn’t help in areas where the dampness cannot dissipate out to the bulk of the ‘dry’ air.
The older I get the more I’m inclined to act my shoe size, not my age.
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horizon
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Re: Mould in houses

Post by horizon »

francovendee wrote: 25 Nov 2022, 8:02am
What set me thinking about this is a friends house that was his home but is now rented out. He'd lived there with his first wife and never had mould problems. I know the property is in good order. His tenant is now insisting the house is damp and mould is forming on the walls.
He's getting someone in to take a look but suspects it is the result of drying washing in the house and not opening windows.
And not just the clothes drying. There are the tenants themselves (q.v. threads on condensation in tents!), showers, washing, open cooking pots, washing up and any heating that forms condensation such as bottle gas heaters.

I'm getting the impression that the general consensus in the media is that heating cures damp: this is primary school level nonsense. In fact, one of my earliest schoolday memories is of a film at school that posed the question as to which will dry better: a heated item with a glass cover over it or one with both the heat and cover removed. Of course, it was the latter.

For most people ventilation is a challenge as it requires opening the windows (often not possible when away from the home for security reasons) and putting on an extra jumper (really not cool :lol:). The answer has been to introduce stealth ventilation in plastic windows or other devices (to ensure that the occupier is unaware of it and won't close it off) while at the same time maintaining the fiction that you can hermetically seal your home to keep warm.
When the pestilence strikes from the East, go far and breathe the cold air deeply. Ignore the sage, stay not indoors. Ho Ri Zon 12th Century Chinese philosopher
Stradageek
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Re: Mould in houses

Post by Stradageek »

Insulate well, keep all furniture away from cold walls, keep all internal doors open to allow air circulation, dry clothes outdoors whenever possible.

We battled with mould for many years, the children leaving home and better insulation are the principal reasons why the house can now run at 18°C with no mould issues.

That said it is interesting to note that friends who have visited cramped Soviet apartments in the winter note that the solution is to have the house hot enough to wander around naked at all times. This comes courtesy of a government controlled 'central' heating system.
bikerider
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Re: Mould in houses

Post by bikerider »

We bought a flat for our son to live in twenty two years ago - ground floor with a flat above under a tiled roof with underground parking conventionally built in 1970. We did the usual modernising decorating stuff and also painted the outside walls in the bedrooms with mould-proof paint (work knowledge)
The lad eventually moved on and we decided to rent out, six further couples occupied until selling earlier this year. We had no complaints from five tenants but the fourth couple, after eight months, complained of damp and mould. They said it had turned some furniture black and also the walls especially round the windows. Potential reasons were explained and a dehumidifier was supplied with little success.
Fortunately for us his work took him away from the area and they left.

John
mumbojumbo
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Re: Mould in houses

Post by mumbojumbo »

A lot of council house were fitted with air bricks/vents in bedrooms etc to help ventilate houses. Too many people keep windows closed and too few dry damp washing outside .Many damp issues can be solved by developing good habits at no cost.
uwidavid
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Re: Mould in houses

Post by uwidavid »

The problem with the vents in plastic windows is when the weather is blowy they let a lot through and very little when it is calm.
Also they are not a very good seal when closed. I put tape over them in winter (and late autumn) to prevent leakage (if I wanted fresh air coming in I would open a window - which I sometimes do).
My house is also fitted with a large number of extractor fans (building regs?) this is the only place I get significant condensation. That is in the ducting pipes of these things. It got so bad last year that the damp caused the main fuse to trip (ground leakage in the fan wiring).
I've sorted it out now (probably non-compliant fix!).
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al_yrpal
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Re: Mould in houses

Post by al_yrpal »

We have ventilation in our 1799 built house....its called draughts!

Al
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Dingdong
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Re: Mould in houses

Post by Dingdong »

In my late teens, I lived in a Victorian flat share near a big open water lake. In winter it felt like the entire village was in the grasp of some unseen brutal chill. Even the local pub felt humid and damp.

The room I had was fine, because it was right next to the boiler, but one of the girls had a room off the ground floor which she complained of being 'permanently cold ', you would see her walking into the kitchen with the duvet wrapped around her shoulders of a morning. On investigation, we found not just mould, but half a dozen mushrooms growing behind the wardrobe. Her old man was a barrister, and got her out of her contract PDQ. The owners solution was to sand it back and paint it, ready for the next victim.

In nearby Manchester, I do recall stories of students being found dead in unventilated flats from CO2 poisoning, all from faulty gas appliances. I've never rented since, a situation I am very grateful for.
peetee
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Re: Mould in houses

Post by peetee »

In my experience a great deal of damp in the house is not transferred through the structure by poor insulation or weatherproofing, rather it is generated by the occupants. Ignorance of this was the dodgy builders ‘bread and butter’ back in the day as many a naive house owner was conned into forking out for DPC, roof tile or cavity work purely on the grounds of excess condensation.
When my daughter returned home there became three occupants at my property and the condensation levels increased appreciably. We have a strict regime with regard to showers and drying clothes indoors. When this is not observed the results are very obvious; the dehumidifier is on constantly and the house feels damp and, crucially, colder than it actually is. The dehumidifier really is a valuable piece of kit in such a house. While windows can be opened to ‘flush out’ damp air they are very small and the path of that air through the house never changes so large areas of the property do not benefit. The dehumidifier however can be put anywhere and I have used it in grotty corners along with a fan heater and it is effective. It’s all rather an expensive business though and undoubtedly I’d have less to do if certain residents would be a bit more thorough at obeying the rules!
The older I get the more I’m inclined to act my shoe size, not my age.
francovendee
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Re: Mould in houses

Post by francovendee »

:lol: :lol: :lol: :lol:
al_yrpal wrote: 25 Nov 2022, 7:34pm We have ventilation in our 1799 built house....its called draughts!

Al
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