G’day Ben ,
My observatory is 3x3x2 m with a gable roof that parts in the middle, for runners I have used uni-strut and 40mm wheel bearings to roll the roof out. Sometimes I find it a bit small and is also built off the ground because of slope. There is a hole in the middle of the floor for the pier which is 800mm into the ground and separate from the floor so you walk around without causing vibration when imaging. The walls are standard walls like a house with insulation and colour bond tin on the outside the roof is RHS steel made into a gable split in the middle with insulation and tin.
To keep the roof close I use ratchet straps and g-clamps which have held up to some very strong winds
ian c
