The posts are normally set at 1.8m centres when using 3.6m (12′) rails.
110mm machined half round posts are best, but you can substitute 100mm to reduce costs if desired.
100mm machined Half Round Rails are suitable for use with stock or horses.
Sawn Rails (3.6m x 38 x 88mm) can be substituted if desired.
Half round posts and rails are all pressure treated.