Mould on the bottom of the inside wall

[lettywetty]

Hi,

I have a bedroom in a L shape on the ground floor. Until last year the only opening of the room where sliding doors. Because the occupants of the house were rarely opening the doors, mould has form on the other end on the wall where the bed was positioned.

I changed the sliding doors for French ones with flaps on the top so that people could let these opened safely even when they were away during the day. But this was not enough to ventilate and I have a wall covered of mould.

This is a north facing wall, single wall.

I took the paper of the wall and will ask someone to built a second inside wall with insulation and plasterboard.

Shall I do anything else for the mould before building that second wall. My husband says that we have to treat the mould before. Shall we do that that and how. There is no structural problem there, we have asked a pro, only lack of ventilation. Can't we just let dry the waal for a few days before adding the second one?

Letty

 

[bobasd]

until you are far better informed maybe its not a good idea to be framing up secondary walls etc.
as you probably know by now, its always best to post photos.

are you involved in flipping houses?

 

[lettywetty]

Hi,

We had the place checked by a company called Kenwood Plc, specialist in damproofing, dry rot ... They said that the problem was just caused by lack of ventilation. So there is nothing serious there.
I was just wondering if I should wipe the wall with a cloth and some specific chemical before the new wall is added or just well ventilate the room for a few days before adding a second wall?

The previous occupants (tenants) used to never open the windows, I know because I live nearby. I lived myself in that house having the bed in the same room and same place and never had any problem of this kind.

See picture of the wall. I removed the paper today which was not a big deals, the main patch of mould is right where the bed used to be.

 

[bobasd]

that certainly is a classic condensation pattern - note its going high up the RH inside corner.
presumably your going to strip all the wallpaper from all the walls?
treat the condensation mould with some kind of solution containing bleach - there's masses of suggestions on here for concoctions.

1. do you have a solid floor?
2. is the wall cavity or solid?
3. can you post a pic of the outside of the wall?
4. do you have a flat roof over any part of the room?
5. you can solve this minor condensation issue without building any walls.

 

[^woody^]

The vent is blocked up, unblock it.

Some properties are more prone to cold sposts and mould due to the location/construction specifics and the available room layout options.; In these cases if you can't get air moving across the whole room, then it may be necessary to line the problem wall with a thermal board or suchlike to remove the cold surface - but still the source of the extra humidity will need dealing with - eg extract fans in kitchen/bathroom and heating usage patterns.

 

[lettywetty]

Hi Woody,

If we build this second isolated wall, and I think we should as the original is a cold single wall, do we still have to re-open this blocked air vent. Because this vent will be then hidden behind the new wall?

Thanks.

Letty

 

[^woody^]

It may be wise to. You can line the vent opening to the face of the new surface and fit a plaster vent cover. The thing is, that recess is not getting any air movement.

BTW, a new wall may be exessive. It may only need 15-25mm of insulation to remove the cold surface, so thermal plaster board, or polystrene board and normal plasterboard may well do.

Moving that radiator to the back wall may even be an option to consider.

 

[lettywetty]

Ok, thank you very much.
Letty