Condensation on vinyl wallpaper

GreySquirrel

Condensation on vinyl wallpaper

I'm redecorating a bedroom which has one external wall which has vinyl wallpaper on it. I dismantled a bed and left the matress and baseboard proped against the window sill overnight. The matress and board were at an angle to the wall.

When I came to strip the paper, the vinyl face was wet all along the area where the matress was lying.

I was surprised at the amount of condensation on the wall and puzzled as to why it is only where the matress is.

The wall under the paper seems dry.

Any observations as to what is goig on here? Should I repaper or paint this wall?

Carlow52

The mattress acted as an insulator against the warmer air in the room so the temperature of the internal face of the wall dropped to below the dew point temperature at which point the water vapour in the room air condensed out onto the wall as water.

Its a wake up call for addressing any excess sources of water vapour in the house ( bathrooms, kitchen, bedrooms...) as well as a clear indicator that u should consider insulating the exterior wall as it points to heat loss

GreySquirrel

Ok, that makes sense. The house was built in the 1950's. The walls are solid blocks. I've had trouble drilling into these; the drill wobbles all over the place and there seems to be small stones in the blocks.

How is the external insulation done?

I did heat loss calculations some years ago to size radiators. I didn't really pay much attention to the figures for the external walls.

Carlow52

i was thinking internally insulating the wall: aka as drylining. external insulation is a whole house project

GreySquirrel

Right. Was thinking about that myself, the drylining. Don't know if finances will stretch that far. Dont think my DIY skills would be up to it either. I'd have to "get a man in".

Carlow52

GreySquirrel wrote: »

Right. Was thinking about that myself, the drylining. Don't know if finances will stretch that far. Dont think my DIY skills would be up to it either. I'd have to "get a man in".

The man in idea should only be done once u are crystal clear on what u want done. The number of cowpokes that are on the go these days is appalling so be sure u know what u want done, because if done wrong the cure is worse than the disease

GreySquirrel

Carlow52 wrote: »

The man in idea should only be done once u are crystal clear on what u want done. The number of cowpokes that are on the go these days is appalling so be sure u know what u want done, because if done wrong the cure is worse than the disease

In the meantime, would you suggest paint or paper for the external wall?

Carlow52

Paint as the paper tends to hold moisture and if u decide to dryline, best not have paper

GreySquirrel

Carlow52 wrote: »

Paint as the paper tends to hold moisture and if u decide to dryline, best not have paper

The inside of the external wall seems to be dry. However there a black stains in places which I take to be mould or mildew stains. They don't seem to be active. I've washed down the wall with bleach, scrubbing the stains clean.

Should I use a primer/sealer on this wall or will that just keep the mold in the plaster?

What would be the best paint to use?

Carlow52

Painting not my forte...:(

GreySquirrel

Carlow52 wrote: »

Painting not my forte...:(

ok