Spacing Requirements On Sheathing
Question:
I am looking for help on the spacing required to screw down a BHP B-36 20 gage roof deck to wooden trusses spaced at 5 ft. 4 in. O.C. and 24 in. O.C. Do you know of any published codes or specifications on the above?
Answer:
For 24 in. O.C. trusses, the only requirement is for continuous top chord bracing (like sheathing). Once the on-center spacing exceeds the capacity of the sheathing (like your 5 ft. 4 in. O.C.), then purlins are installed on the top chord for support. The on-center spacing of the purlins along the truss top chord are part of the information input at the design stage. How the sheathing is attached is beyond the scope of any truss design work. Truss designers do not perform structural roof diaphragm designs. We suggest that you contact your roofing manufacturer or supplier with your concerns.