painting over limewash

[thursdaycat]

I have a feeling I've heard that there is an issue with putting modern elumsion paint over old limewash - is this right?

I have stripped the wallpaper off my bedroom walls to find half the wall area underneath is bare modern gympum plaster (hence will easy to paint) but the other half has got (what I've been told) is old limewash over several prevous layers of paint.

So can one limewash over paint but not paint over limewash? Or am I mis-remembering something?

Thanks again

 

[charlie-ia]

is the page you saw called "paint finishes" posted by jocelyn?

does anyone have any suggestions for narrowing down searches for us beginners?(or is all you can do already listed where you start a search?)
i have the same problem, read so much usefull stuff, then cant find it again

 

[michael]

I'm a bit of a beginner myself but I have a similar problem . All I do know is that limewash will not adhere to modern emulsion. It just runs off. In addition I dont think limewash will adhere to modern Gypsum, I know that this is the case with distemper, somthing to do with its alkalinity and so probably the same for limewash. Not sure about the adhesion of modern emulsion to limewash but if I were you I wouldnt use it unless its one of the breathable variety made by companies like Rose of Jericho etc. You could try modern clay paints, a relatively new product made by a company called Earthborn. These apparently look like the old distempers and limewashes (a nice chalky finish)and have similar breathable properties. The difference beingis that clay paint will stick to anything including emulsion, gypsum and limewash - check with earthborn paints first. [info@earthbornpaints.co.uk] You could also seek advice from Peter Ellis at "Rose of Jericho" who make their own natural paints such as breathable emulsions but not clay paint [info@rose-of-jericho.demon.co.uk]

 

[thursdaycat]

thanks Michael for the really useful leads - these paints sound just the way to go. clay paint sounds very interesting indeed.

 

[NT]

I would be wary of anyone saying distemper and lime wont stick to things, for 2 reasons. The first is I've got lime & distemper on gypsum, and lime on concrete, all of which went on and stayed on without any incident. The 2nd is that soft distemper and washable distemper are frequently confused. The 3rd reason is that all these paints are not alike, there are different distemper formulae, and even different limewash formulae (eg with or without a little linseed, which changes its compatibilities)

The short answer is try a bit, and in most cases its fine.

As far as emulsion on lime based paints, its not an ideal combination, as lime tends to shed its surface eventually, and emulsion forms only a very thin layer, it does not penetrate into the lime as more lime would. Use more lime would be best, but emulsion may be fine if the wall gets a piss coat first, and the lime is brushed properly first. Try a little bit and see...


NT

 

[jocelyn plummer]

Definitely worth spending time talking to Rose of Jericho about this. So far all their advice to me has proved ok , products perform well and great colour choices.

 

[Gervase]

As a lime purist I wouldn't advocate using a non-breathable emulsion over lime or distemper, but...
If you brush the surface well first and apply a coat of 1:1 diluted PVA it will stabilise the lime in readiness for whatever finish you wish to apply.
This will, however, completely destroy any breathability in that face of the wall, so should not be done if damp is an issue. It's really something I would only contemplate for internal lath and plaster walls and never for plaster on brick or masonry.
In a perfect world, however, an oil-bound distemper would be the paint of choice if limewash and water/size distemper are considered too fragile a finish.

 

[thursdaycat]

Gervase - I try to take on board all the wall-breathing arguments but when we had a problem in my son's bedroom I got in 2 specialist lime plasterers and they both said, in essence, "oh don't both with lime, it's really just a purist thing, just use gypsum plaster and paint it with emulsion." and that's on a thick stone external wall. I felt like I tried but they both independently said that lime and breathing walls isn't such a big deal. when teh house was renovated 15 years ago, the builders then plastered everything with gypsum downstairs and it's all fine. So I was quite prepared to throw a coat of dulux emulsion on my bedroom now until I remembered the flaky limewash issue.

I struggle a lot with this house - I'm trying to understand all the period property issues but find it very difficult. this forum is very helpful to get a range of views to try to help build a better picture.

 

[NT]

Gervase - I try to take on board all the wall-breathing arguments but when we had a problem in my son's bedroom I got in 2 specialist lime plasterers and they both said, in essence, "oh don't both with lime, it's really just a purist thing, just use gypsum plaster and paint it with emulsion." and that's on a thick stone external wall. I felt like I tried but they both independently said that lime and breathing walls isn't such a big deal. when teh house was renovated 15 years ago, the builders then plastered everything with gypsum downstairs and it's all fine. So I was quite prepared to throw a coat of dulux emulsion on my bedroom now until I remembered the flaky limewash issue.

I struggle a lot with this house - I'm trying to understand all the period property issues but find it very difficult. this forum is very helpful to get a range of views to try to help build a better picture.

They werent lime plasterers then. In most cases gypsum is not an issue, but it does mean increased risk of cracking, its more vulnerable to water damage, and if painted with emulsion the risk of damp problems is higher. You may well be fine of course, but that isnt always so.


NT