Cement ridges must conform to the following requirements:
o A layer of 250 micron PVC membrane must be placed over the grass on the top.
o A reinforcing layer of 12 mm galvanised bird wire must be embedded into the 75 mm thick cement and sand mix cast on top of the PVC membrane. The cement ridge must be neatly formed, floated and finished, with a 75 mm thickness. (Mix 3 parts river sand with 1 part cement).
All cement ridges must be sealed with a waterproofing membrane.
Grass ridges must have a minimum thickness of 75 mm and be properly formed and secured with 13 mm galvanised bird wire. Grass must be thatched and secured to at least the last two laths on the ridge. All ridges must be will formed and have a sturdy appearance.
Fibre-glass ridging can be made in lengths of up to 9 meters. 2 x 2mm Holes bust be punched or drilled into the bottom 50mm reinforced part of the fibre-glass ridging. The ridge design must be of such a nature, that when installed the top of the ridge fits firmly on the ridge pole.