Lime Plaster: advice please.

[Boholady]

We bought a house built in 1920 back in the summer. I remember the vendor mentioned that the front reception room had needed 'specialist plaster'. We have had extra air bricks added as the room smelt damp and the water content in the walls was a little high.

I'm now wondering if the vendor meant lime plaster? I need to search through the guarantees, etc, that came with the house although I don't remember seeing one for this.

We are now at the stage of wanting to decorate this room. I'm reading that we need to use breathable paint on top of lime plaster. Any recommendations please? I've also read that you shouldn't use normal filler...unfortunately I have already filled some screw holes with polyfilla, so will that be a major problem?

Many thanks in advance for any advice :)

Earthborn or Graphenstone is good for lime plaster. I’d dig out a little of the areas that you’ve used polyfilla in and refill with Lime Putty otherwise the polyfilla will really stand out when you paint it.

Oh boo @MellowMelly :(
Thank you for the paint names :)

No problem. My partner (a plasterer) said if you can’t be bothered with all that then just seal the walls and you can use normal emulsion.

don't put glue on it though!

lime plaster is off white, ranging IME from creamy to very light greyish.

Gypsum plaster is usually pale pink (may be chocolate brown if wet) though medium grey is sometimes seen.

If you drill a hole, or scrape a bit off, you should be able to identify it by colour. Photograph a sample on your hand, if not.

If there was damp, the cause might still be there. It is very often due to a building defect that can be repaired. Post some photos of the whole wall, indicating which area(s) seem damp. Especially if the damp areas are by a concrete floor or a kitchen or bathroom.

Dampness won't be due to the plaster, even if it is lime - that's just allowing damp through that shouldn't be there in the first place. Get someone in to isolate that and fix it - they'll almost certainly be able to diagnose the type of plaster too.

We have had two specialist companies investigate. The original damp problem before we bought the house had been fixed by an injectable damp course. But the previous owners hadn't put in additional air bricks as advised.
We have had 4 air bricks added and there is no longer any damp smell.
Both companies were confident that the damp issue was just that common in a house of this age.

There is no visible damp to show you. The walls aren't damp, they just had a slightly raised reading compared I guess to a modern house. The reading was not over the acceptable range.

Anyway, I've found the guarantee and it just says 'specialist plaster' but doesnt specify lime. I will have a little scrape and see what colour it might be...the walls have been painted dark green!!!

"The original damp problem before we bought the house had been fixed by an injectable damp course"

that's great news.

BTW, how does a chemical mend a leaking pipe, drain or gutter?

My original post was not asking about damp. We are happy with the specialist advice, which has been the same from two companies.

I was asking about what sort of paint to use on lime plaster. Thanks to MellowMelly's advice I was able to research paint and have found a stockist in the next town who I'm sure will be able to help me further.

Many thanks for all the replies :)