Redecorating condensation problem wall

redgie

Hi, we are looking to redecorate a cold wall which suffers from condensation (mould grows up the corners and along the bottom of the wall). It is a cavity wall that has been filled with CWI.

We are doing what we can to tackle ventilation and the amount of moisture in the air, but I need advice on what to do with the cold wall. It was previously papered, mould was growing behind the paper, condition of wall is not good enough to just be painted with an anti-mould paint. It's my daughters' bedroom, and one of the girls has asthma so I want to reduce the chances of mould growing back, but I also want to 'warm' the wall - it's cold to touch even in summer, but icy in winter.

Have considered polystyrene veneer or wallrock thermal liner, lining or blown wallpaper and then anti-mould paint but am worried mould could grow behind the liners/in the adhesive again? Is this method effective? Should I paint the bare wall with anti-mould paint first?

If we were to batten and insulate the wall, which materials are recommended? Can mould grow in insulation? Have also heard about thermal plasterboards - can these be stuck to existing plaster? I'm not worried about losing the space, but cost is an issue.

Finances are pushing me down the wallrock route, but am worried this may be a false economy? I have completely confused myself as to what I should do, so would welcome opinions/ideas please from people who have dealt with this problem successfully.

Thanks in advance

nickj_2

you could baton it , insulate it then plasterboard it , which would make the wall warmer , also you need to ventilate the room with something like this http://www.condensationshop.com/home/
or get a dehumidifier

redgie

Hi
Thanks for the reply, we have a dehumidifier but couldn't combat the condensation last winter, getting a vent is on the list of things to do! If I were to baton, etc. the wall, how can I ensure mould doesn't grow behind the plasterboard? Would 25mm polystyrene be enough?
Thanks

dorsetlady67

Dont know if this is any help but we converted our old outhouse last year into a bedroom [I have disabilities & needed to be downstairs] anyway it had constantly been plaqued by mould & damp before we started renovating.
We got inspectors in who said wash walls down with neat bleach which we did 4 times then we used an anti-fungerside [cant remember name] The we batten and insulate the walls with rockwall then plasterboarded with thickest /best quality plasterboard ,we open both windows fully everyday no matter what the weather.
And you know what we less than 1 yr later have black mould!
It's growing on all the outer side walls,the ceiling & even on the carpet.

Had inspector in & all he said was hummm,whilst scratching head..I suggest you rip it all out & start again!!!
Easier said than done M8T,we havnt got another £350 quid!
Hardware store says if you got black mould you will always have it no matter what you clean it with,iit will come back...that's reasuring

Good luck I hope you find a solution because we couldnt

redgie

dorsetlady, sorry to hear you've had no luck, it's a lot of money and work to do again.

Like you we haven't got a lot of money to throw around, would rather spend a bit more now than have to redo every year which is why we were considering batoning etc. rather than just thermal wallpapering - but your experience doesn't give me confidence. Don't really want to do all that work only to have to redecorate every year anyway.

mummyroysof3

a builder once told me the only way of warming up a wall was to put a raidiator on it...not sure about that though

redgie

Hi mummyroysof3 we added a radiator to the same wall downstairs but it's not had much affect on mould growth unfortunately.

Have stripped wall back to bare plaster and have found an 8mm gap approximately 2 inches deep, down the external corner of the room. The filler which had been used was mouldy so I am in the process of removing this but wondering what can I use to refill - obviously I want something with anti-fungal properties (polyfilla doesn't state anti-fungal) also wondering if I should fill to full depth or would this interfere with a vapour barrier? Sorry if this is a stupid question but have no idea of wall construction. Paint in this area had lifted and flaked. Wooden baton would be in contact with any filler (not sure if this makes any difference?).

Because of dorsetladys experience we have decided to patch wall up as much as possible to paint, and accept that the wall will be very cold. Am considering using anti-condensation paint, with a bathroom anti-mould paint as top coat, to inhibit mould growth as much as possible, but would I need to use a primer or sealer on the bare plaster as well?

If the problems continue this winter we will look at batoning and insulating again, thought we'd try the 'simplest' route first.

dorsetlady67

We have a good sized radiator in the room.
The insulation in the walls is thick,we open windows to circulate the air.

The worst of it is hubby built built in wardrobes & put proper sliding doors but found my clothes started smelling musky & I didnt think nothing of it untill I took a top out to wear & it had mould on it!

I made hubby take off the doors & we used voile curtains to make sure the air could circulate freely but for some reason it's made no difference,my clothes are still musky & im now having to keep all my clothes in vacum storage bags..

It is starting to do my head in
We are going to have to rip it all out & start again by the looks of it but this time we will paint using an anti-mould paint.

myhooose

How about using insulating lining paper which will smooth out the bumps, and use a paint anti mould additive in the wall paper paste. Then paint the wall with paint mixed with the anti mould additive?

I have done similar with just lining paper and the mould has not returned.

You could add some of the additive when making up the polyfilla

cyclonebri1

Not enough in a problem room.

I would bond 3/4" polystyrene to the wall and then over board in 10,, plasterboard, sorry for imp units,

The wack a few screws into the wall to secure the lot, then either skim, fill or decorate.

redgie

I feel for you dorsetlady, it sounds like you've done everything right, I hope you manage to crack it

myhooose, I didn't realise you could use the anti-mould additive in wallpaper paste and polyfiller, that does increase my options, thank you.

Thanks cyclonebri1, what would you use to bond polystyrene to wall? Would you use a layer of adhesive between polystyrene and plasterboard as well?