Installation/laying of timber roofing shingles on a pitched roof
I would like some advice on the installation/laying of western red cedar timber roofing shingles on a pitched roof.
You will need to fasten each shingle with 2 copper clout nails each 2.8x50mm minimum. Every shingle needs to be fixed at or near the nose end with two nails per shingle with the nails positioned a minimum of 25mm from the shingle's long edge. If your rafters are spaced at 450mm then the batten size to use is 50x25mm; spaced at 600mm, batten size is 50x38mm and if rafters are spaced at 900mm your battens' size needs to be 50x50mm minimum.
These shingles are affixed three layers thick on the roof each being individually fixed. Sarking needs to be installed over the rafters prior to fixing of the battens.
Consider the following as an idea only as it is predominantly a method used in Europe. Sheet the entire roof area over the rafters with plywood, affixing counter battens on the plywood in the same direction as the rafters. Place sisalation over the counter battens then batten over the sisalation running across the direction of the counter batten. The shingles are then affixed on this last batten.