Tiny Cargo Trailer Conversion – The Interior

With the roof resealed and basic wiring done, it was time to work on the interior. I started with the insulation. A lot of DIY trailer converters like to use the pink stuff or the blue stuff. Unfortunately, the green stuff was all I could find, perhaps due to a variety of business shutdowns in 2020. So, I went with what I could find. I wasn’t going to lose time due to a minor insulation preference. Plus, I’m not fooling myself into believing that I’m going to camp in extreme heat or cold, especially in this tiny camper. As a result, I think nearly any insulation will be an improvement that’s “good enough.”

The ceiling was next. Used some 1x2s to drop the ceiling a tad. My goal was to use the ceiling for wire routing so that I don’t have to drill wiring holes through the structure and risk having a wire chafe against a hole. The ceiling is a piece of beadboard that was leftover from my shed project. I goofed-up at the front and didn’t notice. That will come into play later in the project. I knew that the beadboard panel was a little short, But I overestimated how much of a gap that my “crown molding” would cover. Anyway, I used a couple of cargo retaining bars to hold the ceiling in place while I cut the opening for the roof fan. Then I screwed the ceiling into place using truss head screws. I painted the ceiling with three coats of matte white exterior latex. I chose exterior paint with the hopes that it is a little tougher than interior paint.

Next, I cut and installed a new floor. It was a very tight fit. You may have noticed that I hadn’t insulated the lower front wall yet. The floor fitment was so tight that the insulation prevented me from getting the floor far enough inside to clear the rear wall. Even without the insulation, I had a very hard time getting the floor through the door and into position. The original came OUT in one piece. So, I knew I’d eventually get this one IN. Laying on the ground and working from beneath the trailer did the trick. I was asked why I didn’t coat the wood. It’s pressure-treated and was still damp when I got it. I was making great progress and didn’t want to wait for it to dry, coat the wood, then wait for it to dry again, and then deal with any warping. I wanted to get it installed and screwed down before it had a chance to warp. I may still coat the exposed sections of the underside.

Now for the walls! The originals were 3/8″ construction grade plywood (pictured here). I wanted a smoother finish and a better fit. I couldn’t find a smooth finish in 3/8″. So, I “upgraded” to 1/2 sidewalls. In the front, I switched to 1/4″ flexible plywood. It enabled me to cover much more of the front wall, which allowed me to use narrower trim strips to cover the gaps. Compare the front wall in this paragraph to the photo I’ve shared in the next paragraph and you’ll see that gap decreased from about six inches to 1-1/2 inches. I was also able to omit the wide trim strips that were with the original walls.

As you can see (or assume?), I painted the walls before I installed them. All of these walls were a TIGHT fit. I’m not saying that large trailer builders have it easy. After all, a big trailer with MY roof’s problems would have been a nightmare! BUT, I have just a 38×42 inch door to squeeze those walls through. I needed every inch, plus the curved nose, to get each wall through in one piece. The front wall went in first (pictured). It was easy since it curls a lot. The passenger side wall went in next since it only has one light on it. The driver’s side wall is where my electrical madness resides…

The wall evolved as I worked. At first, I was just going to power the interior from the lighting circuit. Later, I decided to assemble a switching network that would enable to me to power additional lighting, charge to or power from a battery, and other features that I shared on my electrical page. I attached the side walls with 1-1/4″ self-tapping wafer-head screws and the thinner front walls with 3/4″ self-tapping screws that were leftover from when I attached the roof’s trim ring. I thought I was going to cover the gap between the ceiling and top of the walls with a crown molding. But it proved difficult to find a molding that was flexible enough to curve at the front of the trailer.

I opted to use PVC lattice as my “crown molding.” It is inexpensive and flexible enough to make the curve. Plus, it’s already white. 😀 Remember when I said that I goofed-up the front edge of the ceiling? I misjudged how much my trim would cover, resulting in gaps at the front. I can fill it with white RTV and be happy enough. Instead, I made a small cabinet to cover the gap. When I say “small,” I mean “miniature.” It’s practically a boutique item that’s cosmetic only. I’m after a look more than function. Sure, it’ll hold gloves or rags. But that’s about it. Too large of a cabinet in this small space will certainly result in plenty of head-knocking.

I addressed the gaps in the corners with bendable 1/8″ plywood. These panels are much easier to remove and work with than the original metal flashing. This will be very helpful if I ever need to troubleshoot the lighting circuits. I added a faux wood foam padding on the floor. It looks okay and is easier on my knees than working on the wood floor. The print is a very thin vinyl over the foam, which makes it a little fragile. It’s easy to remove if I have any awkward cargo to move that I think might scratch it. Speaking of cargo, this photo shows the E-track that I installed on the walls. I chose a height that will allow me to store a spare tire beneath a set of 2×4’s, if desired. I’ll share more photos of that setup in the album below. Click here if you’d like to see my video about the interior.

The final phase of my conversion was to refinish the exterior. I’ll share that in my next post.

Close to Completion,


About Scott

I grew up near Houston, TX and served in the U. S. Coast Guard for over 30 years. I have an electronics background and continue to work in the electronics engineering field. I taught myself the basics about automotive systems as well as how to perform some of my own maintenance (cars and bicycles). I became involved with Amateur Radio and computers in 1995. The explosion of technology has made my job and several of my hobbies quite interesting. My hobbies include Volkswagens, bicycling, photography, electronics, amateur radio, web management, and reptiles. Visit my websites to learn more.
This entry was posted in Microlanding, Tiny Cargo Trailer Conversion, Trailer/Cargo. Bookmark the permalink.

Leave a Reply