Purlin Spacing For Corrugated Roofing Nz

Self supporting roofing underlays designed to span between purlins where the purlin spacing is not more than 1200 mm.

Purlin spacing for corrugated roofing nz. For walls nogging spacings shoud be no more that 1200mm. Minimum recommended purlin size is 4 x 2 50mm x 100mm in timber or z140mm x 1 6mm in steel. Z purlins are connected to the rafters using cleats. For curved structures the maximum pulin spacing should be 750mm and a minimum and 14000mm for 5 rib profile.

Longer lengths require specific design. The minimum roof pitch for corrugate is 8 degrees approx 1 7 and if end lapped 10 degrees approx 1 6. Suntuf is supported on the structure via purlins these are the bearers that run left to right along the width of the roof the maximum purlin spacing for the corrugated profile is 800mm centres on the first and last purlins and 1 meter centres for the intermediate purlins. For the greca profile 900mm first and last and 1200mm for the intermediates.

No congregation of foot traffic expected. For roofing purlin batten spacings should be no more than those shown in table x maximum purlin spacings. 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. It often depends on the wideness thickness and the types of roofing materials the climate it has to withstand and many other factors.

Restricted access roof expect occasional foot traffic educated to walk only on the purlin lines in the profile pans or carefully across two profile ribs. Corrugations should run in a straight line between the highest and lowest points and at a right angle to the purlins the intermediate supports. They are a breather type material consisting of bitumen saturated heavyweight kraft paper or fire retardant solvent free laminated two layers reinforced heavyweight kraft paper coated with a water based water repellent. For heavier material such as gage steel the metal roof purlins spacing length could go up to 4 feet.

Minimum purlin size will vary according to span. Good ventilation will also minimise 3. The overlaps ends and sides depends upon the sloop of the roof see below. 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 side by side on each side of the angle of the valley.

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. 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. Corrugated sheet roofing material is widely available and easy to use. For the lighter material such as lightweight aluminum the common spacing length is 4 inches of clear gap.

Patterns should be based on a given wind speed ask them for a roof plan giving purlin spacing and serviceability design loads.