Insulating walls

[ik9000]

Pre 1900 buildings are unlikely to have cavity walls. They will usually be solid masonry, either brick or stone depending on where you live.

Adding anything to the wall will alter its breathability and due point. You may actually worsen the problem rather than solve it. An architect will be able to calculate the wall's properties quite easily.

Mould once into the plaster can only ever be got rid of by removing the plaster entirely, treating the wall behind it and replastering. Short-term a surface treatment of the plaster to kill the visible mould and coating with mould resistant paints will work, but the mould will eventually get through it so it's a time vs cost vs maintenance over time balance.

Check the drains and roof are in good repair and not leaking into or onto the wall. Eg a blocked gutter causing water to run down the wall.

Check also that the room is being ventilated appropriately and not too humid. Any en-suite showers been added? A dehumidifier may be required to control the air moisture content in the room.

Repointing the brickwork will help as most penetration of water will be through the mortar joints I imagine. The age of the building suggests a lime mortar will have been used. The repair should therefore be in a lime mortar also. Overpointing lime mortar with a cement mortar is a very bad idea and will actually cause damage to the wall in the long run.

[htid]

Thanks again for the advice everyone.

It will take too long to reply to each part individually so here is a bit more information. As I am in the roof, my bedroom has a sloping ceiling which meets the top of the vertical outside wall. There is about 1m of vertical wall before the roof starts and it is that wall which has the mould on it, whereas the sloping roof does not. I have no idea if this is true, but logically to me that would suggest it could be the gutters? I'd like to speak to the people in the flat below to see if the top of that wall which is in their flat is the same, however nobody lives there and the landlord lives in Ghana so that's not possible. I went in yesterday evening and left the heating on with all wardrobe doors open, I'll do that every day from now on. Having looked more closely, it doesn't look that moudly to be honest, the only reason I thought it was bad was because, as I say, the previous tenant said that some boxes that he kept in the wardrobe had mould on them. I touched the wall and it crumbled slightly, so I take it it's not plasterboard? It seems more like stone of some sort (I have no idea to be honest). Just as a note, the landlord didn't know anything about the mould until I told her...the previous tenant was moving his things out on 4th and noticed some things had mould on them, I came round to have a look on the evening as he was still there and he told me about it. I then told the landlord about it.

I called the landlord yesterday evening and asked her when the repointing would be done, she said that she hasn't got a clue. The system seems to be that there's a freeholder who owns the building, and a residents association formed of the landlords of the 8 flats. I asked her if the freeholder will be repointing it and she said he takes no interest in the building and doesn't want to know of any problems, so it's left to the residents to sort out any problems. Herein lies the problem, because if it's a big job, either she has to fund it herself, or she has to convince the other landlords to part with their money, which they obviously don't want to do.

I explained to her that the longer it is left, the worse it will become, but she said there's probably not enough money for a long term solution so whatever is done will just be a short term measure. She was very sympathetic to the fact that it is a health issue and can't be ignored and she will be sending somebody round to have a look at it, but we still don't know what the solution will be.

Thanks again for all the help!

[ik9000]

Works to the building itself are the freeholder's responsibility. In the lease there will be a mechanism for the freeholder to charge the leaseholders maintenance fees so it will come back to your landlord and the other leaseholders. Your landlord is not at liberty to undertake the works directly - this will probably be in breach of the terms of their lease.

It might be a leaky roof, or it might be a condensation problem. Only site investigation and some quick calcs on U-Values and dew points will reveal what is actually going on.

In the meantime, a solution of 1:3 bleach, water sponge applied (ie a damp sponge, the aim is not to wet the wall) will remove and kill surface mould. Regularly applied it will control the problem, though not eradicate it. I do this in my bathroom once a month and it keeps things at bay. Obviously bleach on paint = potential problem depending on paint so inform your landlord first. I say inform, not ask since I think (though you will need to check this) that you are entitled to deal with mould as necessary since it is a health hazard. As such your landlord cannot prevent you taking such steps if they are not doing anything about treating the mould themselves. Best to cover your ass first though and inform them upfront in writing so it can't come back on you.

Walls shouldn't be crumbly. It sounds like detached plaster - not uncommon in old buildings. Historically the build-up was lime and horse hair plaster onto the brickwork directly. If the roof has been converted it might have been drylined ie plasterboard lined but it shouldn't be crumbling if that's the case.

[htid]

The landlord said she does know it's the freeholders responsibility, but actually getting him to do things isn't as easy. The roof fixing last year was the responsibility of the freeholder and she said the landlords ended up having to pay for it. The freeholder refused and the only way would be to start court proceedings against him and none of them have the time or money to start that. And she was informed at the time that even if they win and the court forces him to pay, he can still choose not to. To be honest it's nothing to do with me as I obviously deal with the landlord, but I can see the situation she's in.

Just to be clear, the roof isn't crumbly, just the wall with mould on it. I already have some anti mould spray so I was going to use that, however I imagine if I try and rub the wall, it will just crumble more.

[ik9000]

sounds like it's not fit for purpose then mate, maybe start looking for somewhere else.

[GoNz0]

sounds like it's not fit for purpose then mate, maybe start looking for somewhere else.

yep, look for somewhere else

[pushkaknobs]

Whatever you are doing that is for your comfort, you can do what you want until you find it extra burden to your pocket. Its true it makes your wall cooler than present but it cost much.