Damp And Mould

[Cloverjo]

We’ve got a very bad problem with damp and mould in our house which has only just become noticeable. I’m sleeping in one of the rooms with the problem. My son’s room is worse, but he’s not here. Can it be dangerous to sleep in a room with mould growing so prolifically? It smells like a decaying mushroom factory in here.

[tonyav]

Can be, jo.
https://www.bodyandsoul.com.au/health/health-news/is-household-mould-a-health-hazard/news-story/2c44235aff3d411222356d8f9dd6b208

[goodgoalie]

I live in a really old cottage with thick walls, and found that damp problems were relieved hugely when I got a dehumidifier - I'm sure one would help with your mould problem, too.

[hc4361]

I recently had mould develop around my bedroom windows, and very wet window panes every morning. Turns out the blackout blinds caused it. I’ve stopped using the blinds, got rid of the mould using a mould killing spray and open the windows every day for at least half an hour.
Hope your mould is so easy to get to the bottom of.

It’s not healthy at all having mould in the house.

[Cloverjo]

Thank you all. It’s quite horrible. We’ve got a man who says he can fix it but it’s quite a bad problem. I’ll do what you all suggest with dehumidifier, chemicals and getting rid of the blind. There was something quite hideous growing above the railing.

[goodgoalie]

Jo, make sure you get a decent size of humidifier. The little ones you see advertised won't make much difference - you need to be paying at least £100/120. I got mine in Argos and it's just a simple on/off operation, but you should see the water it collects! I don't put it on every night, but when I empty it I always think that all that water would have been somewhere in my house; and the sofa, cushions and curtains feel different after it's been running. And you can run it in different rooms at different times, so bedding etc will benefit, too.
One of my best investments - after my electric blanket :)

[Cloverjo]

Oh gosh, thanks good goalie. I’ve just ordered a cheapo one from Amazon. I think I’d better cancel it.

[chrissa1]

My last flat had bad damp but, not mould. It was a listed building and therefore double glazing was not an option for the landlord.

As it was listed, I was told by a very knowledgeable handyman that the damp was lodged in the spaces between the old stone walls and the new inner walls and the chance of getting rid of it was, minimal.

I hope your house is not as old as mine was.

[johnk]

Check your gutters and get in the loft when it next rains and look for a leak. You're better getting rid of the cause than finding a first aid cure.

[ducksie]

I'm living in a new build apartment, last year my bedrooms and the skylight, mould built up and just opening the front door one would smell the mould in the house, the humidifier came in, was a waste of time and money, I had an engineer in, he checked the walls, in fact, a lot of different kind of specialists arrived, one decided he we should dry line the walls, by now my walls were thick black with mould,he said it would remove the mould but i would lose about an inch from the room spaces all round, eventually a guy said it needed more insulation in the attic and the walls, I had that done last July/August, the difference was noticeable immediately, they pumped beads into the walls, thick amounts of insulation in the attic and the walls and ceilings had that mould removal put on it, in my opinion, you'll be throwing good money after bad buying dehumidifiers etc., until you find the source of the mould and as the last aber suggested, check your gutters, water could be getting in that way and seeping along some gully in your attic, check the ventilation too. It's not healthy to be sleeping in that

[KARL]

The British atmosphere naturally has high humidity to it, especially during the coldest 6-9 months per year. British housing stock is for the most part of notoriously poor quality when it comes to insulation but I genuinely thought that was by now a thing of the past so reading here of someone needing to add insulation to a new building utterly floored me. The UK remains resolutely backward it seems whereas I thought the latest regulations were approaching par with other northern European countries.

Mind you, lifestyle has a lot to do with this problem. We let a flat which never had a problem of this kind then one tenant complained of dampness, the replacement tenant has none (no change to the house before or after but the current tenant heeds the advice). Low or intermittent heating together with no "airing", closing individual rooms off for long periods or most of the time, and using radiators as drying racks (drying washing indoors in general too) are the most common causes. In the old days people rarely had this problem but then they accepted being as cold as the outdoors and had the windows open a lot. The halfway house, of timed heating to low levels without adequate insulation and reduced/no internal or external movement of air, is pretty much a fail-safe recipe for what you describe, Cloverjo.

[Zacs-Master]

Damp and mould are caused by condensation, which is caused by a lack of ventilation.

[Cloverjo]

Thanks everyone. We’re having some investigative work done in a couple of days.
The room that was particularly bad hadn’t been opened or ventilated since Christmas. I think the mould in there was just about ready to get up and walk itself out. :/(

[Tilly2]

Open as many windows as you can Clover. Let some sunshine in.

[alavahalf]

Jo .. carefully read the two last answers from Karl and Zacs and tilly .. all the right answers are right there.
If it isn't a physical problem causing the excess moisture ie . Gutters, roof, pointing etc.
Then your condensation, which causes the mold, is being created within the property. Forget dehumidifiers they are great at removing excess moisture after a disaster at home, but people seem drawn in by the fact that they keep colleting water continuously. As long as the Northern hemisphere contains moisture, your dehumidifier will keep collecting it !
You have just stated that a room concerned hasn't been opened since christmas. There may lie your answer.
Ventilation and background heat, some movement of air will help dramatically.

[ducksie]

For Karl, I live in the new build the same way I lived in my old home for over 50yrs, never had mould there, keep house well heated, not uncomfortably so, plenty of ventilation, don't air clothes - have a garden, clothes line and in winter, if necessary, I dry clothes in dryer,not on rads, the problem was in the attic because while the materials were paid for etc., seems some of the labourers may have left a few rolls of insulation in the back of their vans, now I wouldn't accuse them of that, but on paper, the house was a good energy rating home, but in reality, there was not enough insulation, beams in the attic were damp and on down to the house, therefore the dehumidifier was a waste of money, the apartment is my own, I am not renting from anyone, downsizing - modern buildings tsk, give me the older builds anyday

[TonyV]

Probably others have said you need to find cause of damp. Dehumidifier will remove damp air but you need to find cause. A bleach wash will kill mould.

[ummmm]

Try hiring an industrial dehumidifier and see how much water it collects.

We had one after a flood (burst water tank) and it was shocking how much water it collected. We had to have it on 24/7 for two weeks.

[The Builder]

Please don't go down the de-humidifier route Jo. It's rather like setting one up in the garden, trying to de-humidify the planet. You'll need to run it for the rest of time.
They are really for drying out after floods/severe water leaks etc.

I've dealt with your problem many times. Recently, a barn/annexe. Cold stone walls, minimal ceiling insulation.......... and damp clothes on the storage heater.

There were two exterior walls (bedroom).
Timber battens fixed to walls
50mm Celotex insulation
Plasterboard & finish

Pick an unobtrusive spot (maybe over the wardrobe.)
Fix a simple 150mm x 150mm vent over a hole cut in the ceiling.
If it's an old, draughty roofspace (no roofing felt), then you can get away with leaving the vent unducted. (NOT technically kosher, but better than nothing)
If it's a more modern roofspace, then cheap plastic flexible duct up to a specially inserted vent slate in the roof.

Lay out plenty of ordinary glasswool insulation (the itchy stuff)

Three and a half days work, including going up on the roof, and fitting a vent slate. (They did their own decorating.)

Ventilation and insulation, Jo ;o)

As far as health is concerned - fungal spores equals asthma and other breathing difficulties eventually.

[KARL]

Ducksie, I take it by new build you mean something built within say the last five years. That being so then you describe something that I thought no longer went on, in this case I think there must be grossly sub-standard work involved, as in vis-a-vis the regulations on insulation. That brings up another thought: In woefully many areas, enforcement is seriously inadequate (in the UK) and reliance on "self regulation" and "self enforced compliance" is a UK speciality that manifestly does not work - the fox and the hen house again. Another thing, personally I do not value the energy rating assessments beyond giving a vague guide to comparison - I would assume for any given rating that the true assessment might be at least halfway into the band below. The scheme is deeply flawed and has all the hallmarks of a job creation exercise rather than a serious clarification (as far too many regulatory systems are both in the UK and elsewhere, but in my experience this is more the case in the UK with half baked political box ticking in addition).

Finally, modern petrol driven cars are hugely more reliable than those of (say) 50 years ago and so it is with modern houses. If the house is correctly and well built today it will be a comfortable and reliable one with low running costs. We live in a 140 year old house, one of many around us. We have spent an awful lot of effort and money doing some quite radical things while still maintaining the outward appearance (except for removing all the chimney pots) and all the best features internally (all the fireplaces are of course gone, every last one). I think I could claim it is fit for human habitation (free heating maintaining nominal temperatures at 18 minimum overnight/temporarily away and 23 maximum during waking hours) but I am quite certain our immediate neighbours' house is unfit - during the coldest months it is impossible to maintain 18 degrees there (in any part) and at times 15 can be a struggle. No, while old houses are sometimes architecturally interesting, in other respects (unmodified) they are streets behind modern ones.

Don't do down your heating habits, of course you would not heat beyond what you are comfortable with (ignore others), but do so continuously (not timed/intermittent) and to a consistent level (not seriously up and down) with a minimum well above the outdoors except in the summer. Remember that when you dry your laundry the water does not simply vanish - it goes somewhere else, mostly into the atmosphere. If your dryer is not ducted to the outdoors then the air in the house will have absorbed the water.

[TonyV]

You can read this but ventilation is key.

https://en.m.wikipedia.org/wiki/Dew_point