- Sleeves are used to join the end of successive Zeds over the centre line of the rafters or sections
- A clearance distance of 6mm should be allowed between purlins & rails at jointing points
- Holes are punched 18mm diameter to accept 16mm bolt fixings (corrosive resistant)
- Butted purlins & rails fitted identically but have two bolt end connections only
- Sleeves are fitted between cleats and sheeting rail.
- Side rails can be fitted with wider flange either way (but must be upfacing if using hook bolts)
The end bays are always single spanning zeds jointed to the penultimate bay with sleeves and staggered sleeve joints to remaining primary steelwork. Double span zeds are fixed at mid‑points with 4 fixing bolts through cleats.
A simplified system for smaller spans or for buildings with a lighter load criteria (such as agricultural specification).