What materials for a skim?

[abraxas]

Hi,

I'm planning to give these walls a skim as they're in pretty bad condition after removing wallpaper but I'm not sure how to proceed. Any one got any idea whats already on the walls?

1930s property with solid brick walls, no cavity. There is a black mortar used and looks like this is used for the the scratch coat. It fizzes a bit in vinegar so does that mean lime? What's the white skim coat?

I'm not sure if I can get away with gypsum multifinish or will I need something like limelite finishing plaster?

Thanks

 

[Deleted member 292770]

black coal dust mortar. You may be in Wales or a mining area.
The white top coat is lime plaster.
Are these internal walls ? and is there any sign of dampness?

 

[abraxas]

nice one, the house is over old coal mines in bristol.

ahh good to know it's lime. 3x internal 1x external. no current sign of damp and it's on the 1st floor but i'd want to avoid introducting issues.

do you think limelite is required?

 

[Deleted member 292770]

possibly the external wall if you’re fussy.
Not the internals. multifinish will do you fine.