limewash not drying/setting on damp wall

[fieldfare]

Have painted on a thin layer of (white) limewash on the old lime plaster wall inside our newly acquired cottage. There is a patch of wall which is damp and the limewash is not drying or setting in this area.
Should we:
- be patient and wait a bit longer,
- or accelerate the process by placing an electric fan heater nearby,
- or accelerate the process by adding something to the limewash,
- or give up for now?

(By the way damp problems will be resolved in Spring when we can sort drainage out outside, but we are trying to move ahead with the inside as much as we can now.)

 

[Gervase]

Depends how damp 'damp' is. Limewash likes to be a bit damp to carbonate really well; the Carbon Dioxide needs to be in solution in the form of Carbonic Acid to reaction with the Calcium Hydroxide. But sodden is another matter - that way the CO2 can't get to it at all.
How long have you waited? Two or three days should do the trick if yuoou applied it nice and thin and translucent to start with.
So, in short, be patient!

 

[L1zzy]

I agree wiyth Gervase (he has shed loads of experience much more than me anyway) but I used 3 coats of Limewash over some areas I had repaired to the front of my cottage when it rains the limewash changes colour as I presume the moisture is taken up but then as the weather perks up it becomes more pristine white again. I view it as a healthy sign its doing the bizz and so I would agree with Gervase don't fret its fine - I suspect when you sort out the damp next year it'll appear to become more dry. At worst its not goiing to slip off the wall ! I'm sure you have loads of other stuff to fret over!!