Wall frames are up, the roller beams are in place and the first truss is also in place. All wall frames, roof trusses and roller beams were made from engineered timber (Hyspan (LVL)). This was done not so much for strength, but to help keep all framework straight and square (engineered timbers do not twist due to their nature). This is far more important for an observatory where you need to ensure straight evenly spaced rails for a roll-off roof, than it is for an ordinary shed. Each roller beam consists of 2 lengths of Hyspan (95x36) with 4 cast iron roller bearing wheels supported by high tensile bolts riding between the 2 lengths of Hyspan (which also are blocked for rigidity).