Only have had my Barth about a year... our first RV. Feels good knowing it has a solid aluminum frame and covering. What's interesting is that all the newer ones you see going down the highway appear to be shinny metal too. How are they really made and how does that compare to our Barths?

Fred & Cindy
1990 32' Regency, 8.3 Cummins

Most all have FRP (Fiberglass Reinforced Plastic) sheathing, some over a minimal steel frame. Others, like Newell, have a much more robust frame. Bluebirds were all steel.

Some are framed with wood, and I've seen one video of a manufacturer using #4 pine.

Older Safaris had an all-aluminum superstructure, but the frames are spaced twice as far apart, and they use pop rivets as opposed to Barth which used buck rivets and shaved-head rivets.

Newer Beavers have FRP above the beltline and aluminum below.

Many lower-mid range motorhomes (the majority of them you see on the road) are often termed "stick and staple" when it comes to manufacture. The framing is made of thin studs (compared to a house), exterior fiberglass and interior paneling to cover, and all held together with a whole bunch of staples and glue. Not the most robust materials, especially for a huge box bouncing down the road! It's a cheap way to put them together, and works decently for the lifespan of most RV's.

Many higher-end units have aluminum and steel construction, as mentioned above. Those (like Barth) are your "lifetime" RV's that never seem to out of style!

A couple years ago I saw two interesting videos about RVs. The first was for a 30 plus foot Jayco trailer and they were proud that it was made in about 48 hours. It was definitely "stick and staple".
The second was for a Newell and it took about ten months to build. It was a very stout aluminum/steel frame. I think the shell was fiberglass but of a much higher quality than most. Of course that particular Newell was a special build but I believe nearly all their coaches are.
Just thought I'd add my two cents worth.