stuart noble wrote:

On Sunday, November 26, 2017 at 2:37:36 PM UTC, GB wrote:
On 26/11/2017 14:20, newshound wrote:
On 25/11/2017 17:43, 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.)

Bloody hell what sort of ceiling structure is this? Assuming it is
plaster, rather than concrete, I would probably look to stick in a
suitably shaped bit of plasterboard first, prior to filling with one
coat. Or perhaps fill with scrunched up chicken wire, then plaster of
paris. I'd still expect to need a "finish coat", the modern lightweight
stuff as other posters have said is very good.

It's where a new window was installed. A small chunk of masonry was
hacked out of the window reveal, and the hole was filled with plaster by
the installers. That's lasted about five years (ie long enough for the
installers to be in the clear), and the plaster fell out. Fortunately,
nobody was hurt.

I've been asked to refill it, as there's a bit of a breeze through the
hole. I may have exaggerated the size slightly, but I've bought two 1l
pots of filler, just in case I haven't!

I've never managed a decent finish in one go. Two goes is better, but
that's 2 visits I guess

Experience seems to dffer with the light weight stuff (I assume it is
similar to the B & Q one I used) but more than 12mm on ceiling would sag
too much for me f done in one go. And thick layers take time to harden
trhrough. So I'd definitely go for leaving at least a 6mm gap for a
second coat, preferably more than one day later.

--

Roger Hayter