3: Making the gate.
To establish the gate width, measure between the two gate posts and deduct 25mm (1"). This is to allow 12mm (1/2") clearance each side of the gate.
In this example, the posts are 900mm (3ft) apart so the gate width will need to be 875mm (35"). Use standard 150mm x 25mm (1" x 6") boards 1800mm (6ft) long.
The gate frame: On even ground, make a rectangular frame 875mm (35")wide and 1500mm (5ft) long, out of 75mm x 50mm (2" x 3"). Mark and cut a piece of 75mm x 50mm (2" x 3") lumber and fix in place centrally between the two longer frame members. (Refer to A in diagram.)Note: The frame size referred to is just an example. You can use other stock sizes such as 100mm x 50mm (2" x 4"), 50mm x 50mm (2" x 2"), or even 100mm x 25mm (1" x 4"). It depends on the look you want or the wood you are able to source.
Squaring and bracing the gate frame: Measure the two opposing diagonals of the gate frame. Adjust the frame until the two opposing diagonal measurements are the same, then the corners of the rectangle will be at right angles. (In other words, the frame will be square and not be skew-whiff.) (Refer to B in diagram.)
For the gate bracing, lay a piece of 75mm x 50mm (2" x 3") lumber diagonally from corner to corner on the frame. Mark, cut and fix in place (inside the frame) with galvanized nails. (See diagram.) (Refer to C in diagram.)
Gate vertical boards: Nail the 150mm x 25mm (1" x 6") fence boards to the frame using 60mm (2 1/2") flat head Galvanized nails. The boards will be flush with the sides of the frame and overhanging top and bottom equally. The last board might need to be ripped (cut down lengthwise) in order to fit flush with the edge of the gate frame. (Refer to D in diagram.)