Hi
Sorry to add another lime topic to the list....
We have an old lime plaster ceiling downstairs, on laths. Loads of imperfections and character, many layers of limewash etc. - beautiful, to my eyes anyway. The lime plaster is sound and we want to keep it as it is, just freshening up with limewash - first in white (to tidy it up), and then some final coats of coloured limewash.
The problem is a couple of areas of water staining - one is an area of grungy staining where a pipe has leaked in the past, and the other where there were high ground levels and that whole side of the room was damp (not helped by a leaking immersion heater and lots of boarding everywhere which we stripped out).
I am fairly convinced if we just try putting limewash over the area of staining then several coats later it will still be coming through...
If this was gypsum plaster and a different house, we would paint an impermeable stain stop over the area of staining and go in with emulsion. But I don't think limewash is going to sit very well on top of a layer of something which isn't lime based. Also putting something like Zinsser or shellac on a porous lime ceiling and then finding out it was the wrong thing to when I start to limewash isn't an experiment I really want to try.
I am wondering about taking a scraper and very gently scraping back the top layer(s) of limewash maybe even some of the top coat of fine plaster, and then going in with some lime plaster skim, and then heading into limewash.
Sorry to add another lime topic to the list....
We have an old lime plaster ceiling downstairs, on laths. Loads of imperfections and character, many layers of limewash etc. - beautiful, to my eyes anyway. The lime plaster is sound and we want to keep it as it is, just freshening up with limewash - first in white (to tidy it up), and then some final coats of coloured limewash.
The problem is a couple of areas of water staining - one is an area of grungy staining where a pipe has leaked in the past, and the other where there were high ground levels and that whole side of the room was damp (not helped by a leaking immersion heater and lots of boarding everywhere which we stripped out).
I am fairly convinced if we just try putting limewash over the area of staining then several coats later it will still be coming through...
If this was gypsum plaster and a different house, we would paint an impermeable stain stop over the area of staining and go in with emulsion. But I don't think limewash is going to sit very well on top of a layer of something which isn't lime based. Also putting something like Zinsser or shellac on a porous lime ceiling and then finding out it was the wrong thing to when I start to limewash isn't an experiment I really want to try.
I am wondering about taking a scraper and very gently scraping back the top layer(s) of limewash maybe even some of the top coat of fine plaster, and then going in with some lime plaster skim, and then heading into limewash.