I have an old cast iron tove and a fair length of equally elderly cast iron stove pipe

I need to get it rhough my shed roof, and would prefer to do this in the traitional way rather than using new type components.

As far as I can recall this means cutting a hole in a steel plate about 18" square and weldiing it to the pipe, and then welding a storm collar above it.

Question - when going through a wooden roof, did they used to leave an air gap between the pipe and the plate or just depend on an asbestos sheet mounted below to absrb the heat from the plate?

Anyone got/seen any helpful diagrams or sketches?

Thanks

John D