Roof Anatomy for Repair

[1999UltraC]

Hi. I am new to this group, and seeking info on roof truss location and roof structure of my rv. Can anyone direct me to info on the anatomy of my roof?
I have a 1999 Class C Ultra with a neglected roof leak. I watched many online videos but was still not prepared. Under my rotted roof plywood I have white rigid foam. And some very thin crumbling metal sheets.
I do not see wood trusses.
I am also wondering if the channels in the foam are supposed to house wood or aluminum braces, or just be empty. I believe rodents use them as a travel path.
Thank you.

[THenne1713]

GS generally uses 1-inch square tubing for structure; the foam grooves generally wire runs or air ducts; the brittle metal may have been a foil? Generally a few tubings, then a foam sandwiched between 1/8" or 1/4" wafer board or Lauan or both?

[1999UltraC]

Thank you for your time and info. I appreciate it!

[THenne1713]

Oh, and 1-inch wood framing in/ around areas that will use screws, such as roof vents; See attached BROCHURES

[THenne1713]

Well, tried twice to attach, but not seeing them, so try this? https://www.gulfstreamcoach.com/brochure-archives

[1999UltraC]

Thank you very much!