Purlin Spacing For Metal Roofing Nz

Note compliance with e2 as1 is dependent on purlin spacing and gauge of roofing.

Purlin spacing for metal roofing nz.

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. The introduction of nzs 3604 in 1978 gave specific requirements for rafter purlin and ceiling joist sizes and spacing. Purlins up to 1200mm spacing must be fixed with a 1 10g 80mm long purlin screw minimum or a pryda purlin strap bs 70. It often depends on the wideness thickness and the types of roofing materials the climate it has to withstand and many other factors.

For heavier material such as gage steel the metal roof purlins spacing length could go up to 4 feet. 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. C3 fix side laps and miss 2 hit 1 miss 3 hit 1 miss 2 etc with approved fasteners alone. See section on purlin girt spacing.

When the radius of curvature is close to the minimum the purlin spacing should be reduced to the end span distance for each gauge and profile. For the lighter material such as lightweight aluminum the common spacing length is 4 inches of clear gap. End purlins and periphery of roof to be fixed every 2nd crest. End purlins and periphery of roof to be fixed every 2nd crest.