Site Storage Guidelines
Trussed rafters can be safely stored vertically or horizontally at ground level or on any other properly designed temporary storage platform at or above ground level. If trussed rafters are to be stored on a scaffold, scaffold designers should be made aware of this so they can consider additional loading in the design. The scaffold platform can be extended to allow for safe storage and buttressing can be included to keep the trusses stable. Whichever method and location is chosen the temporary support should be set out to ensure that the units do not make direct contact with the ground or any vegetation and be so arranged as to prevent any distortion.
The delivery of trussed rafters should, wherever possible, be organised to minimise site storage time; however, where longer periods of storage are anticipated then the trusses should be protected with covers fixed in such a way as to allow proper ventilation around the trusses.
When stored vertically bearers should be positioned at the locations where support has been assumed to be provided in the design with stacking carried out against a firm and safe support or by using suitable props.
When trusses are stored horizontally level bearers should be positioned beneath each truss node (minimum) to prevent any deformation and distortion. No other method of storing trussed rafters is considered to be suitable, except where specific provision has been made in the design for an alternative temporary support load case.
Extreme care should be exercised when removing the bindings from a bundle of trusses. As a precaution against destabilisation of the whole bundle of trusses, it is recommended that prior to the removal of the bands, timber battens are fixed across the bundle at several locations with a part driven nail into every truss. Such a simple precaution will allow the safe removal of single trusses once the bands are removed.
Alternative details relating to this procedure and which involve the unbundling of the trusses whilst on the back of the lorry should be communicated by the contractor to the truss manufacturer prior to their delivery to site.