Today I spent some time figuring out how to support the outer edge of the sub floor. I decided to go with my friend, Tom Webster's idea of stepping the sheet down to rest on the longeron. It's not quite that simple, however, since the step needs to be different at the front than at the back. I did a few calculations and ended up with a trapezoidal piece that's 1 1/2 wide at the front end and 1 11/16 wide at the back.

Here's the first of four strips.