by Allen
(Isle of Man)
Paul,
I have removed blown lime plaster from an internal stone wall. I want to bring the wall back out in cement prior to plastering. How is it best achieved to get a good contact with existing stone wall? Then what proportion would the mix be and should I include lime in it.
Thanks for any help you can provide.
Allen
Answer
Hi Allen,
A great mix for this is 6:1::1 (sand:cement:lime) however if breathability is an issue you may want to consider using lime again, in which case contact me - as you may some additional advice, if not familiar with lime But if happy to use the cement mix - the addition of lime does really help.
Then the best tips I can give is to give the stone a good brush. If it is very rough undulating stonework- then stand back and with any type of trowel you want - scoop up some plaster and throw it into all the dips. Then when a reasonable amount is on the wall you can push more in with the more conventional methods that I describe in applying the base coat. (https://www.diyplastering.co.uk/flat-backing-coat.html)
You may need to apply a few coats - letting the previous firm up a little first. Or if really thick a scratch coat can be applied one day and then further coats on subsequent days, but it must be sufficiently scratched and rough so the the next coat can properly adhere.
Hope i haven't confused you too much!
Paul