Different sleepers

Is that DMC Sleepers out of Utah?

 

Never heard that before but I'll be stealing it, LOL.

 

My columbia looks like the Interior plastic is all bonded to the cab. I would have loved to remove it all and spray foamed, then redo the interior. I used some spray foam and a lot of Ruxul insulation stuffed into every nook and crannies I could.
On a different note, I've seen pics where the UNDERNEITH of some of the extended bunks are spray foamed. What kind of spray foam is used? How does it hold up to wet spray and crud? Is there some kind of sealant sprayed over it?