Anti-sag Rods and Eaves Braces
Metsec round lok anti-sag rods and lateral support angles are designed to restrain purlins against twist under wind uplift conditions and contribute support during sheeting.
Round lok anti-sag rods are used for 142, 172, 202, 232 and 262 series, and 45 x 45 x 2mm thick lateral support angles for 302 and 342 series. On roof pitches over 25°, purlin spacings over 2.4m or heavy cladding applications,the lateral support angles must be used on all sections.
When no anti-sag rods are used, temporary spacer bars and propping may be required during the sheeting of the roof.
Where no anti-sag rods are required for wind uplift, and for stability during erection and cladding, we recommend the inclusion of an eaves strut and apex tie.
For roof pitches greater than 25°, use the MetSPEC computer design program to determine section and bracing requirements.
Whenever round lok anti-sag rods are used, the eaves brace should be included as indicated below and the rows made continuous over the apex.
The bolted apex tie detail is adopted when using non-restraining cladding, 302 and 342 series purlins or roof pitches over 25°.
In all other cases where an anti-sag system is required, Metsec tubular sag rods and apex ties are to be used.
All eaves braces are manufactured from 45 x 45 x 2.0mm galvanised angle.
Duo Pitch Roof with/without Anti-Sag Rods
Round Lok Anti Sag Rod for 142, 172, 202, 232, 262 Series
Round Lok Apex Tie
Bolted Apex Tie
Anti-sag Rod Requirements
Wind uplift tables give the minimum anti-sag rod requirements for the various systems.
However, it is recommended that whatever the wind loading, the maximum span without anti-sag rods should be as shown in the tables.
Sleeve, butt and end bays only for heavy end bay system
Purlin ref Span (m) 142 6.1 172 6.6 202/232 7.2 262 7.6 302/342 8.1
Inner bays only for heavy end bay system
Purlin ref Span (m) 142 6.6 172 7.2 202/232 7.6 262 8.1 302/342 8.6
Eaves braces - 142, 172, 202, 232 and 262 series as drawn. Eaves strut as noted
Section 142 172 202 232 262 A 28 43 58 73 88 B 56 86 116 146 176
Lateral support angle (sag bar)/eaves braces for 302 and 342 series and all non-restraining cladding applications