My workshop is but an old barn turned pottery studio. There's no ceiling and the tile roof has only been vaguely insulated. In winter the temperature inside the studio can go down to a couple of degrees above 0 Celsius, i.e. near freezing point.
In the winter of 2002-2003 I had a wood stove and a gaz heater on all day. However the temperature used to come drastically down during the night. One bisque firing came out with a crack under each pot in the form of an S like a Zorro sign with a spelling mistake! From then on I decided not to fire bisques during the winter at all.
This year, apart from a snow storm in January, the winter is amazingly mild. Some days I can fiddle, if not work, in the studio with just a wood stove on.
I've decided to try a glaze kiln.
Here with a paint brush I am putting a layer of a product called XE356B (61356) MULCORIT on the kiln shelves. It prevents pots from sticking for ever on the shelves if by chance a drop of glaze has run.
At first I put the stuff on both sides of each shelf. A bad idea. After a while, it gets hard and flakes of it fall down on the nice glaze of a pot on the shelf below.
Now I use one side of a shelf without any product for bisk firing and the other side with the stuff for glaze firings only.