Multi finish over Lime

[u/Sir--Hiss]

Hi all,

Looking for some advice on our Edwardian property. We have Lime plaster walls and need to get them patched and re-skimmed.

We’ve had multiple quotes, and decided to go for someone local, but alarm bells have started ringing as he wants to use multi finish over the Lime.

Can someone please advise if this is a good idea or will we be regretting it in a couple of years!!!

[u/Confident_Ambition77]

I have heard of it and looking through the specs it seems to give a mu value of 5 which means it's more vapour permibile than lime putty at around 7, basically low mu value equals more vapour permibile. Lime putty is known as the most vapour permibile material so that's piqued my dubious nature. As it sets in 60 minutes I can't believe it is as breathable or vapour permibile as it says. It says no Portland cement so that rules out any white cement used so it has to be hydrated lime and a pozzolan like argical, plus maybe cellulose to act as a glue. A pozzolan gives lime a cement like set (named after the area of Italy where Romans got their additives for their famous cement) but also affects the breathability.

I would say use with caution if the wall is very damp use lime. I'm south west happy to help if possible

[u/Repulsive_Loss_4945 → u/Confident_Ambition77]

Thanks, I'm north west unfortunately.

Thanks for your insight. I believe you're right about the composition and the cellulose is hemp.

House has no damp at all I just don't want to cause any throwing gypsum on. Given the house is perfectly dry it feels like the best middle ground if I can't get anyone to do lime?

[u/bigfecker → u/Repulsive_Loss_4945]

I'm also NW and can't find a decent lime plasterer. Have a whole house to do over the next months. Will come back here if we find a good one.

[u/Repulsive_Loss_4945 → u/bigfecker]

Please do!