On 25/11/2017 18:34, Rob Morley wrote:
On Sat, 25 Nov 2017 17:43:45 +0000
GB wrote:

I need to fill a pretty deep hole in the ceiling. With one fill if at
all possible. Ideally, just some filler that you bung up, and it
stays in place. Any suggestions for the best one for the job (or at
least a pretty good one), please?

It's about 30 cms long, 5-8 cms across, and probably 5 cms deep at
the deepest. (1 foot by 2-3 inches across and 2 inches deep.)

One thing I always do (rightly or wrongly) is turn the rads off in the
room to cool it down as I believe if the room is too hot leading to
rapid drying and more shrinkage.