Closed cell foam with Corrugated Plastic covering it.
Kind of like a RV or Camper has. Closed Cell foam should keep it from becoming saturated with water.
My next Trailer purchase will be plane jane. I do not want any interior, no walls no lights no wires, nothing at all.
I do not like how most are just thrown together. Without much thought or care.
an example would be the type of material used for the walls, some use luan panels, some use aluminum sheeting, both are awful, the luan gets 2 stroke discolored and hard to clean, the aluminum is easy to clean but dents and scratches easy, and now they are using the vhb tape on the interiors so if you mess up a panel you get to deal with that.
I like the
hooks that charmac has, the extruded
aluminum cabinets that charmac uses