Prhaps this might assist:
The guy sent me sample sections, if I get a leak, I will be going this path in the future. there are different thicknesses of it. Hope this helps!
(I had an older rib that was leaking, I decided to get a new one. I then dismantled the old one completely so I would see how they are built. Once I saw the tube structure, I would have no hesitation in using the inner tube idea.....at the price, they won't break the bank & cheaper than a re-tube if funds are tight)