voestalpine 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, voestalpine 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.
For more information visit our downloads page which has access to our purlin technical manual, detailing sheets and section profiles.
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
Inner bays only for heavy end bay system
142, 172, 202, 232 and 262 series as drawn.
Eaves strut as noted.
All holes 18mm diameter for M16 bolts.
Lateral support angle (sag bar)/eaves braces for 302 and 342 series and all non-restraining cladding applications
Tel: +44 (0) 121 601 6000
Fax: +44 (0) 121 601 6065