This **3000mm (3m)** Arris Rail is a crucial component for constructing traditional closeboard or feather-edge fencing. It is typically cut on the diagonal from a rough-sawn $47\text{mm}\times 50\text{mm}$ section to give it its distinctive triangular profile. This angled shape is designed to **prevent water from pooling**, significantly increasing the lifespan of your fence by minimising moisture retention and subsequent rot.
The timber is **Green Pressure Treated (UC3)**, providing deep-penetrating protection against fungal decay and insect infestation, making it highly durable for external use above ground. This rail is primarily used as a horizontal support, to which the vertical feather-edge boards are nailed. It can be installed into **notched timber fence posts** or fixed to square posts using **arris rail brackets**.