Barn door assembly
We chose to put the horizontal pieces of the "Z" at the top and bottom of the door, rather than partway in, to strengthen the door at the stress points where it hangs, and where it extends below and hits the floor. In case we decide to shorten the door slightly, we then raised the bottom horizontal by 1". (The door is shown on its side.)
The door is tongue and groove pine. We glue seven (7) 6" slats together for each door, nominally 3' wide.
The tongue and groove are removed from the sides of the door. The top of the Z boards we cut at a 15-degree angle to shed water.
Then the Z is screwed on from the back (the inside).
The door will receive this clear waterproofing, surfaces that will be inaccessible are treated before assembly.