Suspension of Services and Rafter Restraints

Suspension of Services

Where it is required that services are to be suspended from Purlins the preferred method of the attachment is through the section web. However, fixing to the Purlin lower flange (details 1, 2 and 3 shown below) is usually more convenient and cost effective, the fixing of loads to the lower flange lip is possible, provided certain precautions are taken. Hadley Group Ltd. have concluded from in-house tests on service suspension techniques that the criteria in the following tables should be observed.

Purlin material thickness / mm	Max Load Per Clip /kg	Max Load per Metre run of Purlins/kg	Max Load per Purlin / kg
1.2-1.5	10	15	25
1.6-2.0	20	25	40
2.0-3.0	25	35	50

Tests indicate the above flange loads are permissable

Suspension Methods 1-3

For wrap-around purlin clips such as that illustrated in Figure 1 above, please refer to Archerdale Ltd, of Shipley, West Yorkshire.

Illustration of wrap-around Clip Type

Dust Cover connected by the use of a clip:- For further details on this and other methods of fixing services please contact:- ZED - DUCT SYSTEMS Limited, Unit 5, Hill St. Trading Estate, Kidderminster, Worcs. DY11 6T (Telephone: 01562 824261 Fax: 01562 746435)

For Lightweight Service Loads such as electrical, trunking, light fittings or overhead signs, the F.P. series clip for ‘Z’ Purlins manufactured by W.J. Furse & Co. Ltd. of Nottingham, or Erico Caddy Clips may be utilised.

For suspension of duct work, or heating and ventilation components the Caddy Speed Link by Erico is available.

Clip Types and Illustration

RAFTER RESTRAINTS

Rafter and Column Stays are manufactured from pre-galvanised cold roll formed 45 x 45 x 2mm steel angle, cut and pierced to accept M12 bolts to customer requirements.