Erection Procedure for Simple Domestic Roofs
The following gives guidance on a typical erection sequence for a simple domestic type roof:
Ensure wall plates are level and adequately secured to load bearing walls. Mark off positions of trusses along both plates.
Either mechanically or manually lift the first truss up to the roof holding it in a vertical plane, as far as possible, at all times. Erect the first truss in such a way that it coincides with the position of the end of the rafter diagonal bracing when fitted. Temporarily brace first truss to both wall plates.
Erect second truss ensuring that its production face matches the first truss as indicated by the labels or markings affixed to the truss. Then brace back to first truss with temporary horizontal battens along the rafters and, if necessary, ceiling tie members.
After checking for vertical, erect remaining trusses towards gable end ensuring correct orientation of common manufacturing faces as described above.
Fix the permanent diagonal braces which should be at approximately 45° to final position of tile battens and fixed as high up the first truss as possible and nailed to the wall plate the other end. All permanent braces should be min 22 x 97mm timber and fixed with 2 no. 3.35mm dia. x 75mm long galvanized nails to each truss. Braces may be lap jointed providing the lap spans at least two trusses.
Fix remaining longitudinal bracing to rafters, struts and ceiling ties as shown in Fig. 6. Note that all bracing is repeated for both sides of roof.
All remaining longitudinal diagonal and chevron bracing specified for the roof should now be fixed together with galvanized metal retaining straps to walls and gable ends.
Temporary bracing should now be removed and any additional trusses erected using the completed section of the roof as a means of temporarily bracing them.
After erection and before felting and battening the roof, check that all trusses are aligned vertically and each truss is restrained from bowing out of its vertical plane.