Black mould

[Nicole W]

Hi

Could anyone give me some hints and tips? Our 18C house sits in quite a damp corner of the village, surrounded by trees, has flooded in the past etc etc.

The problem is that our house is growing a lot of black mould - window frames, curtains, inside cupboards, bathroom ceiling etc.

Does anyone know if it's possible to get rid of the mould? When we try and clean it you can still see the 'stains' and it comes back after a short time. We're beginning to worry that it might lead to health issues with ourselves and our children so would like to try and get rid of it as permanently as possible.

Thanks

Nicole

 

[Schoolmarm]

It is condensation causing that type of mould. You need lots of fresh air and heating.

Is there anyway you can get it warmer and drier outside your house too like chopping shrubs down etc.
Are your outside ground levels too high?
Do all your gutters and rainwater goods work properly.

Also any cement/modern plaster etc inside will be stopping the house absorbing your damp.

Do you do lots of steamy things like hot baths, boiling pans, unvented tumble dryer and clothes on radiators?

If so, cold water into bath first
lids tight on pans
extractor fans or windows open
clothes outside.
Are all better options.

Signed steam fanatic of edgworth.
Grrrrrrrrr

 

[Nicole W]

Hi

Thanks for the reply.

The house doesn't have any major planting up to the house (apart from a half dead wisteria!), so I don't think we could do anything there.

Gutters are working OK as far as I know.

Possibly modern plaster isn't helping, but not much we can do about that unfortunately.

Hot baths, boiling pans and tumble dryer are definite possibilities, so will look into changing those.

We have storage heaters not central heating so not much we can do about that either.

Do you know of any products which will get rid of the mould or should we just use a watered-down bleach solution?

Do you think 'small' adjustments to cooking, baths and tumble dryers will make a significant difference?

Thanks

Nicole

 

[Feltwell]

Do you have a "condensing" type tumble dryer, i.e. one that is supposed to catch the water in a tank that you then have to empty?

The vented type, properly vented to the outside, are far better. We had a condensing one for a little while in a rented place and it definitely caused condensation.

Of course even better still is the washing line, when our glorious weather allows!

 

[Nicole W]

Yes we do have a condensing one. What I should do is shut the door and open the windows when it's on.

I do try and put the washing out on the line when possible but the dryer does get a lot of usage.

Thanks

Nicole

 

[Hatster]

The 'small' adjustments add up massively for a family of four or so - think about the amount of baths / showers you're all taking, and the amount of condensation that's chucking into the house. Then there's the boiling kettle several times a day, the saucepans on the hob, your tumble dryer etc...

We've made the following short-term adjustments to deal with black mould in our house:

- bedroom windows opened whenever possible
- other windows opened whenever we can (I leave the back door open all day if I can)
- bathroom 1 window opened during / after use (will install high quality extractor in future, but will probably still open the window)
- power-shower banned from bathroom 2 (no windows, will install high quality extractor in future, but the power-shower will still probably be banned)
- condensing tumble-dryer banned (will remain banned for ever and be put in the shed if I have my way)
- unblocked the air-vent by condensing tumble-dryer (will stay unblocked, and will probably also include a high-quality extractor fan in the utility room)
- black mould scrubbed with bleach
- extractor fan on whenever cooking takes place, left on for a while after cooking finishes
- kettle only boils the exact amount of water needed

We've also massively upgraded the heating controllers so that the house is at a reasonable constant temperature.

So far it seems to be working well. As i say, I just did watered-down bleach, and it hasn't got rid of all the stains yet, but I feel with another round of scrubbing I'd have it shiny white and clean.

 

[JoceAndChris]

Mr Muscle Mould and Mildew killer is rather good.

But it's just a temporary fix... I sympathise, as our house is also prone to damp and the kind of mould you describe. When we moved in last summer and I stocked up the food cupboards everything went mouldy, flour, pasta, it was awful.

This is what we did:

Cut heart shaped holes in all the kitchen units.
Removed the plinth at the side so air could circulate.
Installed a dehumidifier.
Increased heating by means of electric fan heaters.
Every lovely day, open doors/ windows and create a through draft.
Bake more, boil less.
Absolutely no laundry drying in areas prone to damp.
Lots and lots of open fires that carry water out of a room.

Result= no mould, asthma greatly reduced.

 

[Feltwell]

Yes we do have a condensing one. What I should do is shut the door and open the windows when it's on.

I do try and put the washing out on the line when possible but the dryer does get a lot of usage.

Thanks

Nicole

Have you got a spare bedroom? Our dryer was getting used a lot over the winters, with having 2 young kids. Now if the weather's bad we put the clothes on airers in a spare room, with a dehumdifier - it's power consumption is a fraction of that of a tumble dryer. If hung up at night clothes are usually dry by the following morning, the evening for thicker items.

 

[AMc]

If you want a clue to how much water your drier is extracting then compare the weight of the wet clothes going in and the dry clothes coming out.
1 litre of water weighs 1 Kg at 4C - so if your load of clothes are 1Kg lighter at the end of the cycle then that full litre has been pushed into the air to condense when it meets a cold surface. Now imagine pouring a litre of water over the windows in the room and you're starting to see how significant the impact could be. You definitely want that water vented externally.

We have a bathroom that had no natural light despite a velux window installed in the roof above its ceiling. Despite a high power extractor the shower curtain grew black mould. Since we're opened the ceiling to the window the mould has died off - so I reckon sunlight also has been killing the mould.

 

[Flyfisher]

I agree with all the above. Cleaning off the mould is one thing (and necessary of course) but it's only dealing with the symptoms not the underlying problem, which does sound like condensation.

I would try to maximise ventilation, which should be more practical as the weather warms up. Basically just open as many windows as possible and get plenty of fresh air flowing through the house. Open bathroom windows when bathing/showering and kitchen windows when cooking etc. Sleep with bedroom windows open. The more ventilation the better.

I'd be less concerned about heating the house in an attempt to dry it out - ventilation will do just as good a job (and cheaper). Also, warm air will hold more moisture and cooler walls will encourage condensation (and more mould). If the air and walls are the same temperature then condensation will be less of a problem.

All this extra ventilation through the summer months will allow you to learn if condensation really is the problem, in which case you'll have to think how to manage things through the colder months when wide-open windows are less practical. There have already been lots of good suggestions in this regard in the previous posts.

 

[Penners]

First class advice above from Flyfisher and others. Ventilate, ventilate - particularly through the summer months.

As already explained, the fundamental problem is almost certain to be a combination of very damp-laden air in your house, and cold walls. You've had lots of advice about reducing the dampness of your air, but if those measures don't prove to be enough you may ultimately need to think about reducing the coldness of your walls.

What is the structure of the house? Are the walls solid brick, cavity brick (highly unlikely at that age), timberframe with infill... or what?

 

[Hatster]

This is probably the advantage of having a husband who is extremely sensitive to the smell of damp (I actually can't smell it) - he picks up on rooms getting damp very quickly and insists on having windows flung open as much as possible.

 

[JoceAndChris]

As already explained, the fundamental problem is almost certain to be a combination of very damp-laden air in your house, and cold walls. You've had lots of advice about reducing the dampness of your air, but if those measures don't prove to be enough you may ultimately need to think about reducing the coldness of your walls.

So how do you reduce the coldness of your walls? My wall sandwich on the ground and first floor is cement render, a couple of feet of stone, lime plaster, lime wash, modern paint, wallpaper. (I think wallpaper is a warming thing, consider tramps in newspaper) In the undercroft where all the cooking takes place it's cement render, stone or brick, left exposed on the interior.

There's nowhere for insulation to go is there? Apart from the roof, and that's insulated, though I suspect it's not been done well.

If I were to lime plaster and limewash the undercroft as it would have been originally - would it warm up the walls?

Nicole - don't mean to steal your thread, do come back and tell us about the structure of your house.

 

[Penners]

So how do you reduce the coldness of your walls?

One technique is to apply treated battens to the interior of the walls (to create an air gap), then fix insulated plasterboard to the battens.

You do, of course, sacrifice some room size, and you have to ensure that air can circulate in the air gap, by providing ventilation top and bottom. But in serious cases of condensation this can be effective.

 

[Flyfisher]

Also known as 'dry lining' I believe. Quite a few rooms in our place have this arrangement and not all of it modern by any means. For example, the drawing room is oak timber frame construction but when it was given its Georgian makeover (complete with cutting away some original timbers to make way for 'new' windows) the original oak frame, complete with wattle and daub, was internally framed with 3x2 timbers and then lath-and-hair-lime-plastered to square everything up, as was the Georgian fashion I believe. So it's a time-honoured technique.

 

[worms]

I found that having a humidity meter (mine is part of an electricity usage meter: http://www.theowl.com/index.php?page=about-owl) and a dehumidifier (mine is one of these: http://www.amazon.co.uk/Premiair-DD122FW-71-DAY-Desiccant-Dehumidifier/dp/B000E13IPY) has worked wonders. I am now much more aware of when the house is getting damper, how this relates to household activity or outside conditions and can try to change habits accordingly.

 

[JoceAndChris]

Interesting...thankyou. I have to confess I've been reading this term "dry-lining"on the forum and wondering if you meant something like the wallpaper here:

Now that would be very cheap, warm and absorbent.

 

[biffvernon]

We've had moans about conifers and millipedes, woodlice and silverfish. Who will now speak up for the slimemoulds? A truely fascinating group of organisms forming an important part of the food web as they clean up on bacteria.

Let's hear it for the Myxomycetes.

Further reading:

 

[JoceAndChris]

Oh, Biff. You're such a tease. I am going to check in as an anonymous quest in your lovely home and do a full survey of how many of these organisms you allow in your house. :wink:

 

[biffvernon]

Pretty obviously, starling, jackdaw, house sparrow, swallow, pipistrelle, while smaller creatures need searching out.