Monopitch, Flat & Curved Roof Systems
Monopitch Roof Sytems 0-250
If no support can be provided by connection between the uppermost purlin and the main steelwork at mid-span or third points (according to span), we recommend our standard diagonal tie wires are used, fixed at both ends with bracing brackets and a rigid-fix strut, between the top two purlins. If a purlin spans greater than 3.500m on a monopitch roof system then restraints are necessary. Additional diagonal bracing may be required depending upon the length of the roof slope.
Where there is an adequate hot rolled member at theeaves, Hi-Span struts can be used utilising the flexibility of both FB and AC cleats, as shown. This alleviates the necessity for diagonal bracing.
Flat Roof System 0-50
When a roof pitch is less than 5 degrees, rigid fix struts are used in place of sag bars as the more robust restraint is capable of resisting a small compressive force that mat occur with this system. As a further precaution we recommend an additional set of diagonal braces with a reversed orientation as shown in the diagram below.
The bracing system required for a curved roof depends upon the prulin arrangement. Where the purlins are equally spaced about the ridge the standard bracing for a duo-pitch roof can be used. If the purlins are spaced unevenly, then the roof should be treated as two seperate mono-pitch systems. Therefore each side of the roof has its own set of struts and diagonals