103/2015 11 11. Technical documentation and data sheets 11 Application Product code Page Principles of design WT 11.3 Principles of design WR 11.9 Connecting main and secondary timber beams WT / WR 11.15 Joining timber rafters WT 11.23 Connection of purlins to main trusses WT / WR 11.29 Dowelled purlins WT / WR 11.35 Lateral compression reinfor-cements WT / WR 11.41 Simplified fire protection rating WT / WR / WB 11.47 Load-carrying capacity WS 11.49 Timber toTimber and Steel to Timber Connections WF 11.51