paint and lime plaster

[notenoughsocks]

Hello

I have just bought a 1930s council house (perhaps mid-late 1930s). Upstairs we had quite a lot of work done. I stripped back all the wall paper, spent ages scrubbing buckets of old paste and paint mix off the wall till I reached the stage where it was as clean as I could get it. Back to the plaster here and there, but to a stable looking paint layer elsewhere.

Anyhow, I used the dreaded pollycell basecoat to cover up as much as I could then put on a couple of coats of magnolia. It all looks great (a few days in) but I am worried now that I may have painted over lime plaster with a non-breathable (the pollycell) paint. How long do you think it would be before a reaction would show. Also - how could I identify if it was lime plaster or not? It is definatley not the pinky brown of the newer plaster which you can see where the electrics were chased in.

Any advise/experience would be gratefully received.

 

[TheDec]

If it is lime mortar and you were to rub your hand over it, it would leave a chalky powdery residue. It does sound as if it may be if so it should have been sealed prior to painting.

Dec

 

[notenoughsocks]

thanks dec. How long do you think before it would begin to show?
Also - hopeful thought - if the pollycell is non breathable would that act as a seal?

 

[notenoughsocks]

Thanks Dec

Two questions:

How long do you think before it would start to show?
Also - I don't suppose the pollycell would act to seal it if it is not breathable <hopeful emoticon>

 

[xr4x4]

Doess the lime plaster need to breathe if the wall doesn't?

 

[TheDec]

If this is lime mortar your problem now is not breathability it's what you applied over it, any dry powdery surface needs to be as I said sealed prior to the application of paint. The chances are that given time it will start to lift and flake and I can't offer you a timescale, at this moment of time it hasn't been established that you have painted over either a lime mortar, wash, or distemper substrate.

Dec