Advice on lime skimming

[jessio]

Hello
I'm looking for advice because there's alot of information out there.
We recently had our 1902 house rewired.we started to fill in ready for a gypsum skim but started to research and I've read it's a bad idea because the top skim will crack because it's on lime.
So I'm wondering about lime skimming it myself buying a ready made lime putty? but I don't know how to get the wall back to a state where it will accept the top like skim?
Any ideas? It's currently got an old paint on it and the chases are back filled with whatever modern plasterers use.

 

[a twig]

DG27 seems to be a popular preparation for surfaces before skimming, have a search for it on here and you’ll find plenty of posts/threads

 

[Lacan07]

If your not overly concerned about damp then its fine to gypsum skim, your plasterer should scrim all joints and prep the surface with watered down PVA which helps the plaster adhere. I've had some internal walls gypsum plastered here and they show no sign of cracking. They do this kind of thing all the time.

If you want breathability and choose to skim with lime you key the surface with a devil float, or such like, before giving the wall a good watering. Ready mix, putty based lime is easier to use than NHL.

Unfortunately you indicate your walls have been previously painted (so you're not in fact skimming on to lime). Unless this is Lead paint your walls aren't breathable, so it would be a waste of money skimming with lime anyway.

 

[paulc]

If your not overly concerned about damp then its fine to gypsum skim, your plasterer should scrim all joints and prep the surface with watered down PVA which helps the plaster adhere. I've had some internal walls gypsum plastered here and they show no sign of cracking.

Quite a few plasterers are using SBR now rather than PVA.. Febond Bluegrit also works for suction control and provides a grippy base for lime - Used it on a wall in my kitchen that has a mix of gypsum and gloss paints on the walls. I wanted a lime finish, and the Febond seems to be holding up.

 

[Lacan07]

Quite a few plasterers are using SBR now rather than PVA.. Febond Bluegrit also works for suction control and provides a grippy base for lime - Used it on a wall in my kitchen that has a mix of gypsum and gloss paints on the walls. I wanted a lime finish, and the Febond seems to be holding up.

Yes, I've heard good things about bluegrit, and as you say the sandy texture provides a good key.

 

[jessio]

If your not overly concerned about damp then its fine to gypsum skim, your plasterer should scrim all joints and prep the surface with watered down PVA which helps the plaster adhere. I've had some internal walls gypsum plastered here and they show no sign of cracking. They do this kind of thing all the time.

If you want breathability and choose to skim with lime you key the surface with a devil float, or such like, before giving the wall a good watering. Ready mix, putty based lime is easier to use than NHL.

Unfortunately you indicate your walls have been previously painted (so you're not in fact skimming on to lime). Unless this is Lead paint your walls aren't breathable, so it would be a waste of money skimming with lime anyway.

Thanks for your reply. it's helpful. I'm going to remove the paint as much as possible with paint stripper and go from there I think. I have today found a couple of lime options that might work. Many thanks for the information

 

[Monty]

As you are removing the paint, then you can re-skim with a lime finishing plaster. All you need to do is thoroughly damp down the wall first so that the old plaster doesn't suck out the moisture in the new finishing plaster too soon. I've done this in a few rooms and it's always worked.

 

[jessio]

As you are removing the paint, then you can re-skim with a lime finishing plaster. All you need to do is thoroughly damp down the wall first so that the old plaster doesn't suck out the moisture in the new finishing plaster too soon. I've done this in a few rooms and it's always worked.

Hi do you need to score it too? Thanks

 

[Lacan07]

Hi do you need to score it too? Thanks

Yes, I would. Its best to provide a key, unless you've already roughed up the surface by removing the paint.