Purlin Spacing For Metal Roof Nz

For heavier material such as gage steel the metal roof purlins spacing length could go up to 4 feet.

Purlin spacing for metal roof nz.

The purpose of the purlins is to provide a solid foundation for the metal roofing panels and trim to be screwed to. It should be noted that timber purlins for metal roof cladding are minimum 70mm x 45mm h1 2 18 moisture content and that battens used previously for tiles must not be used. The adjustable cleat can be rotated up to 15 degrees from normal to accommodate the change in angle from vertical portal to the roof slope of the rafter. Fastener patterns on nzs 3604 buildings should be consistent throughout the roof excluding top and bottom rows.

The typical spacing standards for residential and commercial buildings are about 1 to 2 foot. Purlins are non pressure treated 1 x 4 x 12 lumber that is installed on to the roof in a specific layout pattern and screw pattern. For 2x4s purlins the posts are spaced in 4 feet distance. Rafters were birdsmouthed over the top plate and extended beyond the wall framing to create the eaves.

The purlin spacings should be limited to the lower of the trafficable limitations and design wind load with the capacity of the structure. For 2x6s purlins the posts are spaced in 6 feet distance. By the standard the most used placement of purlin span for metal roof is five foot intervals. Purlins up to 1200mm spacing must be fixed with a 1 10g 80mm long purlin screw minimum or a pryda purlin strap bs 70.

Where the end purlin spacing is less than 800mm an adjustable end brace with a bolted end cleat is available as twisting of the end cleat is not practical. This result should be referenced to the wind load span design graphs. If the space between posts is greater than 8 feet then brace is needed to avoid buckling. Do all roofing projects require purlins.

Purlin batten purlin batten fixing type d 3 45kn 2 blue screws or 2 skew nails plus 2 wire dogs for purlin on edge fixing type c 2 4kn purlin batten 1 blue screw 2 nails fixing type b 0 8kn purlin batten fixing type a 0 55kn 1 nail purlin batten note. Two nails maybe preferred to prevent batten rolling over with high roof pitches. We do recommend it however. For the lighter material such as lightweight aluminum the common spacing length is 4 inches of clear gap.

Ridge boards were 25 mm 1 wide with a depth dependent on the rafter size.