I have just ripped out the old kitchen units and am staggered at the amount of black mould present on the walls behind even though the walls are dry and there are no leaks in the pipework or nothing.
My first instinct is to wash the walls several times with domestic bleach allowing a day between each washing.
Then again, I read that the spores could be well embedded within the plaster and that the bleach treatment would only be temporary.
I want to get this problem sorted before I ask someone to re-plaster the whole room and get the new kitchen installed.
What would be the best permanent treatment to kill the mould and its spores stone dead?
Condensation would be expected there against an outside wall.
Thermal insulation so the wall surface doesn't get cold.
I don't bother to put backs on cupboards against outside 9" brick walls, as this pretty much guarantees a cold area where condensation will form, although it's also important not to pile things up against the back wall in that case, or those items have the same effect as the cupboard back -- insulating the wall from the room.
Killing the mould is pointless. Unless you change the conditions which allowed it to grow, it will simply reappear, and if you change the conditions (e.g. get rid of the condensation), then it can't grow. You'll need to wash off the surface mould before replastering, but that won't kill the mould. Paints anfd washes with fungicides exist, but I'm not a fan of introducing such toxins in the home.
What you could do is stick insulation board to the wall behind the cupboards. It needs to be sealed around the edge so air from the room can't get behind it. Also, don't paint it -- the mould is probably deriving its nutriants from the paint.
You could just ignore the problem. It's probably been there since just after the last kitchen was fitted. Has it caused you any problems over that period?
Excellent advice Andrew. Good point about not painting the insulation board ... didn't know it may provide food for mould ... must remember that one.
When we bought our 1900 house there was a fair amount of mould on some of the exterior walls (no cavity but double brick) behind the old kitchen cabinets. When we fitted the kitchen we ran the radiator pipes around the back of all the cabinets just above the floor which has helped to remove the cold and damp spots on the walls whilst at the same time providing a more balanced heating of the kitchen and no black mould on the walls.
I don't think household bleach kills mould, it just removes its colour so it looks as though it's gone. As for what does kill it I have no idea.
Ordinary household bleach (sodium hypochlorite), diluted in plain water, is a very effective fungicide and will kill mould. However, it will not prevent its subsequent return.
Dunno, but mould from condensation is common in rented properties, I sort out about half a dozen a year on average. The Polycell stuff works, as does their Stain Stop paint.
Never get call backs. Always write a disclaimer on the invoice, roughly 'it will come back if you don't sort out the cause'.
I've just had to do a the ceiling in an inbuilt wardrobe. There's was no real ventilation and the loft directly above was not insulated. My local DIY store had bottles of fungicides for internal and external walls. I also painted the wall with a Dulux bathroom paint that contains a fungicide. This stated five years mould free. So I'll probably give another coat in a few years.
As with the other posts, you need to deal with the underlying cause if at all possible i.e. insulation and ventilation.
One tip with the fungicide, when it says don't leave in contact with the skin it means it. I was using rubber gloves with a fabric material at the wrist. I got some of the fungicide on the material but thought it wouldn't be an issue and finished the job. I had a reaction to it and it left a sore rash for a few days afterwards.
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.