Here is Cliff from Texas’s version of a Tent Topped Camping Trailer. He began with a 4’x8′ flat-bed Carry-On trailer. He assembled everything with weather-proofing in mind.
He used exterior grade plywood and assembled everything with waterproof glue and counter sunk coated fasteners. Next, he caulked and filled with plastic filler then he painted it with two coats of super premium exterior paint. For added protection; the floor received a double coat of a rubberized asphalt.
One area that Cliff’s trailer differs from how Explorer Boxes are normally built is the use of pre-fabricated RV doors. This is a good trade-off for some people as they are quick and easy to install, compared to making your own doors, although they will increase the cost of your trailer project.