Anatomy of a Tent Trailer

If you’re a DIY’er interested in building a Tent Topped Camping Trailer, here is a high-level overview of their anatomy and things to consider.

I break them down into three main subsystems:

1.) The frame which provides a foundation.

2.) A trailer box for storing your gear and

3.) A tent unit for sleeping and protection during inclement weather.

Frames

Our trailer frames have a 4’ x 6’ bed area and use an extended tongue. The longer tongue improves handling and provides space for a tongue mounted bike rack. We’ve found steel frames to be the best way to balance cost and weight. You can get additional weight reductions using aluminum, although the cost per pound saved, starts to climb. Micro trailers with smaller bed areas for motorcycles or two-seaters are also possible.

There are various frame alternatives that provide a sufficient foundation to build from. Small flat bed utility trailers can be purchased from many sources; mail order bolt together, “box” stores, trailer dealers or custom made. If you’re a proficient welder, plan sets are also available from various sources. Also, good used ones can often be found at reasonable prices.

Tires are an area many people don’t think about, you should. You want tires that aren’t so small they’re turning at warp speed or so big they add unnecessary weight. We like 5.30 x 12 B rated trailer tire and steel rims. This combination provides a substantial load carrying safety factor and good weight verses revolutions balance. Attractive 12” aluminum rims are available that shave 3 lbs off, but cost three to four times what a steel wheel does. It’s also possible to put matching tow vehicle tires/wheels on in many cases.

Lastly, leveling / stabilizer jacks are an important item for ensuring a good nights sleep. Normally a tongue jack and a pair of rear stabilizer jacks are sufficient for leveling a compact trailer.

Trailer boxes

When discussing trailer boxes I like to start with, how will they be used and what do you plan on taking? What is your camping style? Are you off the beaten path, in designated campgrounds, road-tripping / doing rallies, in a different site every night or going somewhere and setting up for a while? Perform a gear and equipment inventory of the items you take camping and any planned new ones, also don’t forget toys such as kayaks and bikes.

If you normally camp at locations with amenities such as picnic tables and water, and you go somewhere and stay a few days, a basic box may be sufficient. The focus is more on providing the extra space necessary for hauling everything. If you like to camp off the beaten path or are on the move every day, an outfitted box may better fit your needs. Think of it as a “camping box” on wheels with built-in storage compartments for organizing food, cooking supplies, plates, utensils, etc. You’ll need counter top space for food prep, cooking and clean-up. Also don’t forget water storage.

Now lets look at trailer box building materials. My personal favorite is marine plywood. For DIY’ers with basic woodworking skills you can build a durable, strong and attractive trailer box from marine plywood, waterproof glue and a few screws. For skilled woodworkers, wood strips and veneer open the door to creating functional works of Art. I use marine grade BS-1088 Okoume plywood when building boxes and Titebond III or epoxy based adhesives. Here are several of the ways you can finish a trailer box: Textured polyurethane (roll-on bed liner material) is easy to apply and forgiving of surface imperfections. Exposed wood allows for a beautiful finish, although this takes more prep, yet is still straightforward. It’s also possible to apply boat enamels and automotive type paint although the prep is lengthy if you want a glassy smooth finish.

Another straightforward approach is a Utilitarian box. With this method, you create a lightweight steel structure welded to the frame, then add filler panels of steel, aluminum or wood.

An aluminum box is also a possibility. I had one made for my first trailer but have moved away from them due to cost. If someone is interested in one, I can check with my aluminum fabricator.

If designing your own, one important dimension to consider is the height of the sides, this will determine how much clearance you have under the tent unit. In most cases I find coolers to be the tallest item you need to plan for. We design around fitting Coleman’s steel series coolers, so 17” of clearance is necessary.

Tent Units

Outside of the usual, quality construction, good ventilation, and a dry nights sleep, there are a couple of things I look for. First, ease of use and rapid setup. Can you simply take the cover off and pull it open? Second, will it mount on top of the trailer and not require unloading of the trailer box to use. These become very important, when getting into a campsite late, when you’re tired and just want to go to bed. You can literally pull into a level spot and have almost instant accommodations.

We have a few approaches for providing a dry, comfortable place to sleep out of the critter zone. The first one uses an expedition style rooftop tent system typically found in Australia and South Africa. The folding design of these tents make them ideal for mounting on top of small trailers.