Patterns should be based on a given wind speed ask them for a roof plan giving purlin spacing and serviceability design loads.
Roof purlin spacing nz.
Roof bracing hipped roof construction does not require additional bracing but gabled roofs require both roof plane and roof space bracing.
Step 1 rafter spacing the rafter span is 3 000 m and because this is a light roof the far right column of nzs 3604 2011 table 10 1 rafters for all wind zones see figure 2 can be used for rafter spacings at 1200 mm see note 4 in table 10 1.
The typical spacing standards for residential and commercial buildings are about 1 to 2 foot.
In the valleys due to the angle typically produced at the valley and the use of transition flashing it is essential that the purlins are doubled in the valleys that is two purlins.
Www miteknz co nz copi 2020 mit holis i all is s ma 2020 purlin batten fixing chart fixing type e 5 5kn 2 nails plus 1 ct200 or 1 pair of cpc40 cpc40 cpc40 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.
The minimum roof pitch for corrugate is 8 degrees approx 1 7 and if end lapped 10 degrees approx 1 6.
Or ultimate loads in respect of clip fastened products ultimate loads can be converted to serviceability loads if necessary by applying a factor of 71 in all parts of the country.
When a combination of sheets provide a run of in excess of 40 metres and up to 60 metres the roof pitch should be increased by 1 degree.
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.
Doubling up in the valleys refer to the installation manual for the proper on center spacing and be sure that the purlin is attached to the roofing truss.
Purlins up to 1200mm spacing must be fixed with a 1 10g 80mm long purlin screw minimum or a pryda purlin strap bs 70.
For the lighter material such as lightweight aluminum the common spacing length is 4 inches of clear gap.
Purlins typically 75 x 50 mm and fixed across the rafters were spaced at 760 900 mm centres depending on the roof cladding.
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.
Longer lengths require specific design.
