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lime plaster on lime plaster
- Thread starter MrT
- Start date
Gervase
Member
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- 1,500
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- North London
You'll need to scarify the old plaster to provide a key - you can make up a 'devil float' to do that out of a piece of flat board with some masonry nails knocked through it with the points sticking out a couple of millimetres and a block screwed to the back for a handle.
If the old plaster has been painted you'll also have to remove the paint, unless it's limewash, in which case you're OK.
A couple of hours before applying the first coat of new plaster, give it a good wetting. Then, just before you start, give the surface a going over with dilute limewash to help adhesion. To build up to an inch you'll need at least two coats before your finish skim, so make sure each coat is well and truly compacted with a wood float, and that the surface is scratched to give a good key for the next coat.
If the old plaster has been painted you'll also have to remove the paint, unless it's limewash, in which case you're OK.
A couple of hours before applying the first coat of new plaster, give it a good wetting. Then, just before you start, give the surface a going over with dilute limewash to help adhesion. To build up to an inch you'll need at least two coats before your finish skim, so make sure each coat is well and truly compacted with a wood float, and that the surface is scratched to give a good key for the next coat.
May I ask why you want 2" of plaster on your walls because if there is nothing wrong with it, an inch of plaster is perfectly acceptable.
But if for whatever reason you want to plaster over the existing then bear in mind that whatever you put on top of the existing plaster will only be as good as sound as the existing plaster so it is important to remove all friable loose and blown plaster before applying any new. Other than that, what Gervase said.
But if for whatever reason you want to plaster over the existing then bear in mind that whatever you put on top of the existing plaster will only be as good as sound as the existing plaster so it is important to remove all friable loose and blown plaster before applying any new. Other than that, what Gervase said.
Thanks Gervase. Probably one extra layer and skim will do the trick.
BMcD, I was giving approx values. I've put in some metal electric boxes and the plaster is lower by about half cm. So I guess current plaster is about 3/4 inch. I Suppose I'm giong for less than 2 inches but enough to cover the conduit and recessed boxes. Thicker plaster helps with sound as well.
BMcD, I was giving approx values. I've put in some metal electric boxes and the plaster is lower by about half cm. So I guess current plaster is about 3/4 inch. I Suppose I'm giong for less than 2 inches but enough to cover the conduit and recessed boxes. Thicker plaster helps with sound as well.
Anne
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- 51
- Location
- Monmouthshire
I'd try and just plaster over the old plaster, see if it works lime is really forgiving and may well stick just find to old lime plaster. In fact I'd be surprised if you had trouble with it.