Metal Roofing Framing Spacing

For the lighter material such as lightweight aluminum the common spacing length is 4 inches of clear gap.

Metal roofing framing spacing.

Roof pitch the metal roofing panels shown in this manual require a mini mum slope of 2 per foot to ensure proper drainage. If care is taken metal roofing application can be aided by pre drilling panels allowing screws to go quickly and accurately into the desired spacing. Rafter spacing depends on the roofing panel size. All purlin joints must be supported by a rafter.

Screw line spacing for metal roofing over metal purlins this will depend upon the type of panel that is used and the thickness of the steel. For heavier material such as gage steel the metal roof purlins spacing length could go up to 4 feet. An engineer will use a load chart in order to determine the spacing between metal purlins. Z purlins are connected to the rafters using cleats.

The trim and roofing sheet should be fastened every 12 to 24 inches along the gable edge. Purlins provide horizontal support for the sheets and form part of the framework for the building. Refer to the rain carrying table in this booklet for the maximum allowable panel length per. The same concept holds true for roof trusses.

This allows the panels to be securely attached to the rafters for maximum stability. So the space between rafters can be greater without reducing the maximum span. Once the purlin spacing is determined then the metal roofing panels are typically attached to every line of purlins. Minimum recommended purlin size is 4 x 2 50mm x 100mm in timber or z140mm x 1 6mm in steel.