Tiled / Mansard / Green Roof Systems
Due to increased bi-axial bending caused by  the weight of these finishes, we recommend using our rigid fix strut members in place of  our sag bars. The apex purlins should be tied using the rigid fix apex tie. The top two purlins  require diagonal tie wires and brackets. Additional bracing will be required for every 6.000m of roof.
Each timber rafter must be positively secured to each line of purlins by a bolted or screwed fixing detail capable of transmitting the appropriate in-plane shear load. At the ridge, timber rafters should be joined across the apex or securely fixed to a suitable ridge board.

Stiffened Cleat Connection

Rigid Apex Tie

 Steep Roof System + 25^o
For roof pitches greater than 25^o diagonal bracing members are mandatory. These are capable of transmitting the in-plane component of the load. All sag bars are to be replaced with rigid fix struts.
Standard purlin cleats may need to be stiffened or replaced by purpose made cleats (by others) capable of supporting the in-plane shear load. In addition attension must be paid to the presence of adequate shear strength in the fixing between all the timber rafters and the supporting zed purlins. Again rigid fix apex ties are required across the apex.