Newbie here, looking at a used 2011 23B...
Roof, walls and floors seem to be solid; no evidence of water damage I could find after a couple hours of looking.
I did notice that the black membrane on the underside of the trailer seem a little loose in all four corners. I've tried searching the forum, as I seem to recall seeing a thread about this. But so far my "google-fu" has failed me.
I've attached a pic that shows what I'm talking about.
1) What the heck is this thing called for future searches
2) Is this a problem or normal?