2006 Krystal Coach 28 Panels

[Geninc]

Hi folks,

My dad and I are currently in the process of converting a Krystal shuttle bus 28' into a motorhome. Our first task is to basically cut the van in half horizontally in order to raise the interior height and remove the windows. We will be using 3M Panel bonding adhesive, rivets and new aluminum sheets for the exterior. Now the original specs specify .063 aluminum panels on the exterior but no statement to the aluminum grade is made. Can someone here point us in the right direction as to which grade aluminum should be used (2024, 5052, 6061 etc)?
Very much appreciate any feedback.

 

[Gary RV_Wizard]

I have no real engineering expertise to offer, but the marine construction I've seen typically uses 6061-T6. RVs with flat (not corrugated) aluminum panels seems much flimsier, probably for weight reasons, but they have structural aluminum in the sidewalls for strength.
I would think if there is adequate structure in the side walls, any panel would be ok, subject to considerations like dents and such. Is there vertical structure to support the roof and attach the panels?