Fixing the rails and fence boards
Fixing the Fence Rails:
Fix a string line to both of the end posts 1750mm (70″) above ground, and mark all the intermediate posts along the string line.
Trim the top of the posts at the height marks.
Nail the top rail flat on top of the posts (fig 1). One rail will span two sections (3 posts).
Cut, fit and nail the middle and bottom rail in between the posts so that the underside of the bottom rail is 1550mm (62″) down from the top of the post, about 200mm (8″) off the ground and the middle rail is central between top and bottom rail.
Fixing the Fence Boards:
Fix the first board at the start of the fence line with the top of the board 50mm (2″) above the top rail. The bottom of the board should also be 50mm (2″) from ground. Use a plumb level to ensure the board is plumb (vertical) and nail in place using 60mm (2 1/4″) galvanized flathead nails, 2 at each rail.
Temporary fix another board in place at the other end of the fence line.
Fix a string line to the top of both end boards, pull taut and raise slightly using a nail as a packer (fig 2).
Continue by placing another board against the first and just below the string line.
Nail in place and repeat that action until all boards are in place.
Check, as you are going, about every 10th board with a plumb level for plumb (vertical), and make any necessary adjustments. Ensure the tops of the palings do not touch the string line. keep approx 3mm (1/8″) below. This can be done by eye.