DonC wrote:

We're initially envisioning an 18' by 10' manually operated, soffit
mounted awning -- which matches the norm around here. Our "soffit"
consists of 3" x 8" joists 24" OC.

You'll want to roll them up at night incase of rain or heavy weather while
you're sleeping, and during times of above-moderate winds, so the winding
and unwinding is a frequent occurance. I use motorized awnings. You might
want to reconsider getting manual.
--
Dave
www.davebbq.com