Step 1: Sketch Out A Plan
Our first inspiration was a "Frontier Fort Playhouse Built From Stockade Fencing" designed by John Lewis, and available free on the web. While small, Mr. Lewis's design is cost-conscious and looks easy to build. Unlike ours, his is made without framing or siding the walls one board at a time. Instead, he simply uses pre-fabricated and spaced stockade fencing PANELS turned sideways, and uses a lightweight roof. We take our hats off for Mr. Lewis for inspiring us with his fine concept... but I reckon it just wasn't all we we wanted.
What we wanted was a much bigger fort (ours is bigger in every dimension, twice the volume, and the ceiling high enough that an adult can stand inside). We wanted a stronger fort (ours will hold the weight of a heavy cedar shingle roof plus a dad and kids who want to sit on it to look at the stars). We wanted it to be craftsman quality (ours is framed with 2x4's like a house and is sided with individually routed and cut pine fence boards). And we wanted ours to have a Texas-sized personality (ours has saloon doors, rustic trim, a wood burned sign and lots of other "extras"). And we didn't mind too much if it took more time and materials to get there.
It's impossible to give credit to all that inspired us. Some our ideas came from just looking at Old West buildings at an amusement park.
There is a link to our plans on this page which we followed until we got to the roof structures.* This Instructable will show you what we did.