Specks of mould where wallpaper's been stripped

Cabby

Last Sunday my DH started stripping off the woodchip which has papered the landing walls since we moved into our house 9 years ago.

The exterior wall is now showing speckles of black mould on the bare wall underneath - both under the windowsill and towards the centre of the wall.

what could have caused the mould to have appeared so quickly and how do we treat it? the house itself is over 100 years old and the landing window.does leak a little when it rains. some of the plaster underneath is also crumbling but not so much that we need to get a plasterer in, DH is planning to do that himself...

any help greatly appreciated and sorry for any typos, am typing this on my phone on the bus!

grizzly1911

Cabby wrote: »

Last Sunday my DH started stripping off the woodchip which has papered the landing walls since we moved into our house 9 years ago.

The exterior wall is now showing speckles of black mould on the bare wall underneath - both under the windowsill and towards the centre of the wall.

what could have caused the mould to have appeared so quickly and how do we treat it? the house itself is over 100 years old and the landing window.does leak a little when it rains. some of the plaster underneath is also crumbling but not so much that we need to get a plasterer in, DH is planning to do that himself...

any help greatly appreciated and sorry for any typos, am typing this on my phone on the bus!

Mold will because of damp.

This will be either water ingress from somewhere, poor window seal, leaking roof, broken guttering or leaking internal piping.

It may also be from water vapour from general living, cooking, heating, drying not escaping from the house and condensing on the walls/windows and then being absorbed by the paper/plaster.

For both you need to cure/resolve the cause.

The degree to which the mold has taken hold will affect what needs to be done to make good once it has dried out.

That may range from bleaching in some form to plaster removal.

Most modern wallpaper pastes have an antifungal additive but older types didn't and if these get damp seem to be propagators. It may be that the spores were already there and removing the painted paper allowed the moisture in.

Cabby

thanks grizzly, that would make sense as we've had laundry drying on the radiators these past few days as the dryer's broken.

so if we finish stripping the rest of the walls and treat with fungicide before fixing up the plaster and repapering that might be enough?

Yolina

I think the culprit is most likely the window that you say is leaking when it rains

grizzly1911

Was the mold there when you took the wallpaper off or has it started since?

As yolina says if the wall is very damp I would go with the window.

If the mold has suddenly started and the wall isn't damp as such then could be the drying.

Either way you still need to fix the leaky window too.

djb99

if you intend to re-paint , use a fungicidal wash first. about £10 for 5ltrs, dilutes with water to make 25ltrs. try to allow condensation to escape ( small window left open) or keep doors closed while bathing, cooking etc. I doubt that u have a damp problem because u say the stains r small spots. also damp is quite ugly and usually damages plaster because it has travelled from outside across brick mortar, undercoat plaster and finally through to the top coat. you have a problem with a leaking window that you need to fix but this is not causing spots imo. Decorator with about 30yrs experience.