Arris rail is a triangular rail that fits into notched posts which are often used for feather-edge fencing. This would normally be used in preference to standard fence rails as it gives a neater finish from the back of the fence. However it can be difficult to use arris rail if the ground is sloping. Arris rail is also often used (under felt) around the edges of flat roofing.
Our arris rails are pressure treated green.