I am planning that on this build, any hints sir. Mine are vertical, will it work.
Yep, sure Bob.....in hindsight I would've sprayed prior to installing, then put the finish coat on once it's up. I used a brad nailer for the install, secured at the top and bottom, and a few in the center. I used silicone for an adhesive in the middle, with minimal fasteners, because it allows for a little more flex than say construction adhesive, that can dry hard.
I used a pine 8' long , pre packed product from Home Depot.
http://www.homedepot.com/webapp/wcs...roductId=202075051&R=202075051#specifications
I liked it and was drawn to it because the back had relief grooves, that allow for cupping as it drys and ages, but it seemed to be very dry as it was. My guess is that it will bow a slight amount due to coats of finish (that could be prevented by coating/sealing both sides. It's super lightweight, a 1/4" thick, easy to handle, easy to cut, and looks good finished.
I think the real secret is to have someone cutting outside and handing you the boards, as you install them inside, as crawling in and out is real PITA. I left the product short at the top corners, as I used it for a wiring chase. I have trim cut that is 45 degree beveled on both sides (about 3" wide), and screwed in at an angle to cover the wiring. This was done to allow for future addition of any other wiring...or chasing down a problem with the existing.
In your case you have metal tubing (I had wood) for studs, so you have to run some 1/2"-3/4" stringers to fasten to. Thinking out loud...I would probably devise a template, for the separate walls and ceiling, that would allow you make up a panel, and set them inside, ready for installation prior to the roof or outside being closed up.
PM me if you need anymore help or assistance.