These units will be built with a fiberglass exterior and interior walls. So they can be used as a whiteboard inside the trailer. The fiberglass walls are laminated together with 2 layers of Luann backer for extra strength and a thick foam core insulation. (See attached pictures). Roof is a rubber roof with a 12 year warranty on the membrane itself. These units will all be built to CSA specs and compliant with CSA coding in Canada.