Replastering

[darwen]

Hi,

We're about to separate one of our bedrooms to create two singles. Part of this is going to be plastering the external walls as the plaster is blown in places.
The house is a stone built end terrace, somewhere around 1880. We had some condensation problems when we moved in but have fitted some mechanical ventilation which seems to have cured it. Other than that we've not got damp issues (in this room anyway!).
So the question is, do we need to use lime plaster? Other houses around the area all seem to use plasterboard and skim.

Cheers

 

[livias]

No assuming it is a nice dry interior you don't need to use lime, it is a case of aesthetics.
A compromise would be to plasterboard and then skim it with one coat plaster (does it still exist?) which has a more rustic finish
Another compromise would be to use fake limewash (limewash plus PVA) on the gypsum plaster
Depends how much of a purist you are. I'm a total purist

 

[livias]

Hm have just reread your post more carefully and realise you are talking about an external wall not a partition wall, so I would be more fussy about using lime myself. No need to go looking for problems

 

[MatthewC]

Yes, use lime as it will help the wall to breathe as intended. If you don't you could easily have dampness retained if the wall gets soaked and the wall will feel cold as a result; it would also take longer to dry out.

How good is the stonework and pointing on the exterior side of the wall?

M

 

[darwen]

Hi,
The exterior of the wall is in good nick.

What sort of finish do you get with lime plaster?

Cheers

 

[El Greyo]

Lime is probably the best option but I'm sure there are plenty of houses where gypsum or plasterboard have been used without problem.

Will you be doing this yourself? Personally as an amateur, I much prefer using lime plaster than modern plaster. It's more time consuming by far but, without the years of skills of a trained plasterer, I find it much easier to get a nice finish. I don't get a perfect flat surface but that would not suit an old cottage like ours anyway. Professionals generally prefer modern plaster as it is much quicker and usually what they are used to.

 

[Zebra]

What sort of finish do you get with lime plaster?

It depends. If you use a top coat made from lime putty and "silver" sand (kiln dried sand) and polish it, you can get a very smooth finish. A forum member plasticpigeon noted, with some dismay I think, that his completed lime plastered wall was barely distinguishable from skimmed plasterboard.
Or you can omit the top coat, and sponge the coat beneath instead. This "float coat" has a coarser sand, either a mix of sharp and soft, or plastering sand. This will give you a gritty finish. If you do it this way, you can also make, by hand, rounded corners instead of the razor-sharp edges of modern plaster. I think this looks good, although it's quite "rustic" and perhaps best suited to older cottages instead of georgian or victorian properties.