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There is no shortage of commercially manufactured teardrop trailers out there, but some people prefer to build their own custom trailers to match their specific needs. Aside from that, building your own custom teardrop trailer can be quite an experience!
If you’ve been also thinking about building a custom teardrop trailer, then our guide below may be helpful for you.
Things you will need
There are many tools and parts that you will need when building your own custom teardrop trailer. The most important are:
- Trailer frame.
- Doors and windows. You may build these yourself, but to make things easier, we’d advise you to go for prebuilt ones.
- Plywood sheets.
- 2 x 2-inch structural lumber.
- Structural adhesive.
- Many screws and bolts.
- Impact driver.
- Belt sander.
The very first thing you will need to do is get a trailer frame. And arguably, this is the easiest step since there are many prebuilt frames available on the market.
You can build a trailer frame yourself, but we think that it would be easier to go for one of the prebuilt frames available out there. You should find a trailer frame at some tool supply houses or major home improvement centers.
Usually, prebuilt trailer frames are sized at 4 x 8 feet, which makes for a pretty small teardrop trailer. You can find 5 x 8 feet frames as well for some more free room.
When it comes to frame material, people usually go for aluminum since it’s lightweight yet quite strong.
If you are going to build a trailer frame yourself, go for steel angle rather than for steel tubing. Steel tubing is stronger than steel angle, but at the typical sizes and cargo capacity requirements of teardrop trailers, the increase in strength will be pointless. Plus, it will make the frame much heavier than you need.
Teardrop trailers tend to be heavy in the back since the kitchen is located there. Needless to say, a back-heavy teardrop trailer is going to have compromised stability when towing. To compensate for the weight shifted to the back, consider adding some weight in the front later on in the project. For example, you may install a water tank in the front.
You may also move the axles and wheels closer to the rear. 6-12 inches should be enough, though this will depend on the original position of the axle. You will need to do some metalworking in order to readjust the position of the wheels, so you may have a professional do it for you if you aren’t that good with it.
After you’ve got the trailer frame completely set up and adjusted to your needs, the next step is building the flooring.
To make the base of the flooring, people usually go for 3/4-inch plywood. To ensure structural integrity, you should go for pressure-treated plywood. If you use other types of plywood, it is likely that they will decompose from outdoor elements, like water splashing onto the bottom when driving. Undercoating will do its part, but why not go for extra strength and get pressure-treated plywood?
To make the flooring, you will actually need two 3/4-inch plywood pieces. Between them, you will place the floor insulation to keep the interior of the trailer warm.
Needless to say, the plywood needs to be sized like the trailer frame. If you get larger plywood, you will need to cut it down.
In order to allow for room for the insulation, as well as to increase the strength of the flooring, you will need to build a frame between the two plywood pieces. Since insulation is usually sold with a thickness of an inch, the height of the frame between the plywood pieces will need to be 1 inch.
To make the framing, we’d advise you to go for 2 x 2-inch lumber. Buy plenty of it since there are a lot of areas in the trailer where you will need them.
To make the insulation sit flush with the layers of plywood, you may need to saw off the excess inch of the 2 x 2-inch lumber with a table saw if you have one, or have someone else do it. After trimming the lumber, you’ll get pieces that are 1 inch tall and 2 inches wide.
Next, you will need to build the frame on top of one of the plywood pieces. You may have to shorten the lumber pieces so that they fit the plywood.
To fixate the lumber in place, you may use some construction adhesive. Aside from that, screw the frame into the plywood as well. To keep the lumber stable when screwing it down and to help the adhesive cure, secure it with clamps.
How densely you should place the screws will depend on your preferences – some people like to give a palm width between the screws for good strength.
An important thing to remember here is that you will need to mark the location of the screws on the flooring. That’s because you will need to screw down the other plywood sheet to the frame, as well as later screw down the trailer’s walls to the flooring.
To mark the screws, just put some Xs on the side of the frame where they are located. This is a thing that you will need to do onward as well.
Then, to make the flooring stronger, place a lumber piece lengthwise in the middle of the frame. Shorten this piece so that it fits between the front and rear ends of the frame, as well as don’t forget to make it 1 inch tall like the rest of the framing.
Furthermore, you may want to add some lumber across the framing as well to increase the floor’s strength even more. Most people place just 2 planks across, cutting them in the middle and slightly shortening the halves so that they fit between the middle support and the outer sides of the frame.
Fixate all this lumber in the same way you did with the edges – with screws and adhesive. In the end, you get a frame that is separated into 6 rectangular sections.
After that, you need to drill some holes in the frame, through which you will then bolt the flooring to the trailer frame. Make holes on the edges of the frame, as well as at the center support beam that you installed earlier. 3-4 holes along the width and 4-5 holes lengthwise should be sufficient. You will also need to drill some bolt holes in the trailer frame as well.
Now, apply some undercoating to the upper surface of the plywood. This side of the plywood will actually be facing down when mounted on the trailer frame.
People typically use fibered asphalt roof coating, which is designed for flat roofs but does a good job of protecting the trailer bottom. Fibered asphalt roof coating is very messy and takes a long time to dry, so as an alternative, you may opt for rubberized wood paint. Remember that you should use a respirator when applying any coatings.
If you are using pressure-treated plywood, you would need to let it sit for around 6 six months for drying out and only then apply any coatings. This is because new pressure-treated plywood contains resin that is still wet.
After the undercoating is applied, you need to mount the flooring to your trailer frame with the coated side facing the road. To mount the flooring to the trailer frame, you may need to drill some bolt holes in the frame.
Then comes the time to place down the insulation. Insulation usually comes in large sheets, so you will need to do some measurements in order to cut it down and fit the pieces in the flooring’s frame. Make sure to size the insulation as precisely as possible.
After the insulation is placed, squeeze some adhesive onto the surface of the frame, both on the edges and the inside supports. Then, put the second piece of plywood on top. After positioning it flush with the frame, screw the plywood down into, while keeping in mind the position of the screws that you connected the bottom plywood and the frame with.
Since this side of the flooring will face the interior and since you will drive the walls into it, you should use fewer screws. In fact, you may want to avoid using screws anywhere other than the edge frames in order to keep the interior flooring smooth. You may secure the galley side though since it will be hidden under a countertop.
Again, remember to mark the position of the screws on the side of the frame.
In the end, you get a sandwich of plywood sheets with framing and insulation in between installed on the trailer frame.
After you’ve installed the flooring on the trailer frame, your next step is to build the trailer walls. Walls, just like the floor, will be a sandwich of outer layers with insulation plus wiring in between.
To begin your wall making process, you will need to get 2 sheets of plywood, preferably 1 inch thick to fit the insulation. Plus, you will need a thin piece of hardboard to make a template for the wall shape.
When building walls, RVers usually start from the middle layer of the sandwich. They take a diagram of a teardrop interior wall, draw it onto a sufficiently large paper sheet, glue the sheet to a hardboard with the drawing facing up, saw off the excess hardboard, place it against the plywood, and make the teardrop shape.
An alternative to this method is using a large Styrofoam insulation sheet as a core between two thin outer and inner layers of plywood. This method may allow for better insulation, but it is more difficult to bring into life since you will have to add wood supports in the areas where things need to attach, as well as to reinforce the wall structure.
Due to this, we think that you should stick to the below plan.
Making a template
So, first comes preparing the template.
To draw the template on a paper sheet, you can project its image onto a large wall, mount the sheet to the same wall, and draw a line along the outer edge of the diagram. You may also have the template printed if you don’t have a projector.
Then, as we mentioned above, glue the sheet to the hardboard with the drawing facing up. Cut the excess material off the hardboard with a jigsaw. If necessary, refine the edges with a belt sander.
Shaping the plywood
After you’ve brought the template into the desired shape, you need to attach it to the plywood sheets. In order to do this, you can use brad nails or alternatively clamps. If you use clamps, you will need to move them around as you cut the shape so that they don’t interfere with the jigsaw.
If the cutting capacity of your jigsaw allows it, you may attach the template to one of the plywood sheets, put this sheet on top of the second sheet, clamp them together, and saw them simultaneously. This can allow you to shape both plywood sheets as closely as possible.
If you don’t have a sufficient jigsaw, you’ll have to shape the plywood sheets one by one. Once you’re done, you can put the plywood sheets on top of each other, clamp them together, and even them out with a belt sander.
You may need to even things out with a sander tool even if you sawed the two plywood sheets simultaneously, so keep that in mind.
Making holes and openings in the plywood
Aside from shaping the plywood into a teardrop, you need to make holes in it for openings like doors and windows, as well as some additional holes to allow for room for insulation and wiring and to reduce the overall weight of the wall.
With the holes for doors (and windows if you want them), you will need to be accurate. As for the other holes intended to free room for insulation and wiring, you don’t need to be as precise and meticulous. If you plan to buy doors and windows rather than to make them, make sure to do measurements to make correctly-sized holes.
Again, if your jigsaw allows it, it is pretty easy to make nearly identical holes in two plywood sheets. Otherwise, you’d again need to saw the holes in the plywood separately and then put them on top of one another to smoothen things out.
Finish the exterior of the walls
Once the walls are all made, you will need to apply a thin protective panel to its exterior side. People usually go for plywood or aluminum, depending on their needs or preference. Plywood tends to look better, so you may want to go for it if you care about design.
It’s fairly easy to cover the exterior of the walls – you just apply adhesive to the outer surface of the wall frameworks, stick the paneling on, and let the adhesive cure. To ensure good adhesion, you may use clamps on the wall’s edges, as well as place some sheets of plywood on top.
Some people mount the walls onto the trailer frame and then panel it, but others first panel them and then mount them on the frame. The latter is arguably easier to do since applying pressure onto the panel for curing is more convenient with it.
Placing the wall framework on the trailer frame
After you’ve skinned the wall framework pieces, it is time to mount them onto the trailer frame. To do this, mount the frameworks onto the sides of the flooring, with the bottom edge of the framework flush with the underside of the flooring.
To fixate the walls in place, you can use glue and structural screws. Some people use a tongue and groove method instead of screws, so you may opt for it as well if you want it.
In a teardrop trailer, the roof basically extends from the bottom rear end of the trailer to its bottom front. The roof is a whole structure, except for the kitchen hatch in the rear end of the trailer.
Again, like it was with the flooring and walls, the roof is a 3-layer structure with inner and outer skins and structural support and insulation in between.
Making the roof is arguably easier than making the walls, mainly because you don’t have to think about the roof support structure that much. The walls are the most important structural components in the trailer. The roof only has to support its own weight.
Aside from protecting the interior from outdoor elements, what the roof does is preventing the walls from collapsing.
To support the outer layer of the roof, you will need to make roof bows. They will need to run from the bottom of the trailer’s front up until the area where the kitchen-bedroom partition is. The last bow will serve as the mounting location for the kitchen hatch.
To make the roof bows, you can use 2 x 2-inch dimensional lumber cut in a way to fit between the walls. Lay out the position of the bows along the upper edge of the walls and cut the bows. Nail the bows in place so that their top is flush with the top of the walls. This will allow the roof to overlap with the walls, offering additional protection from outdoor elements.
To reinforce the roof structure, you may want to use dowels. Depending on the thickness of your trailer’s walls, you may or may not need to make your own dowels. We’d recommend you to use at least 3-inch-long dowels. If you can’t find such dowels in stores, you will have to make them yourself.
Aside from that, you will need to make sure that the finish nails or screws aren’t in the way of the dowels.
To increase the support of the roof bows, you may reinforce them with 1-inch steel or aluminum angles on the inside. While this will significantly increase the roof strength, bending the angles to fit the shape of the bows is a great challenge and will not be possible without proper tools.
Supports may also make the installation of the inside wall or roof covering harder. Due to this, you may want to consider installing the angle brackets to the sides of the bows where they will be hidden behind the insulation.
Kitchen partition & hatch
For the kitchen, there are two major components that you will need to build – the kitchen-bedroom partition and the kitchen hatch.
Making the partition is relatively easy. You need to pick the spot where the kitchen will separate from the bedroom, measure the width and height between the floor and the last bow that you will be attaching the hatch to, and make the partition from a plywood sheet.
As for the hatch, you should be building the frame for the kitchen hatch when installing the roof bows.
Since the last roof bow above the partition is where the hatch will be mounted to, this bow will need to be stronger than the others. To reinforce the latch, some people also place an additional bow after the last hatch.
Keep in mind that building the hatch and its supports is going to be much trickier than building the rest of the roof. This is due to the increased support you need to provide to the hatch.
If you limit the hatch support to just bows, it will eventually flex and break. Thus, you need to reinforce the hatch with at least four curved longitudinal runners. These can be made from either laminate or plywood.
You will also need to add supports between the longitudinal pieces. In addition, make sure to reinforce the corners of the hatch as well.
Another thing you will need to pay attention to is sealing in order to prevent water from entering the kitchen. One way of doing this is by attaching aluminum angles around the edges of the hatch so that it overlaps with the roof.
On the leading edge over the roof skin, you should attach another angle piece in order to divert water coming from the top of the roof. Then, install rubber seals under the angle to complete the sealing of the kitchen hatch.
One option of sealing the top edge is installing the so-called hurricane hinge, which is called so due to its shape. These hinges are designed to create a barrier that is nearly impossible for the water to pass. If you can find hurricane hinges, consider using them since they are easier to install than aluminum angle and rubber seals.
Insulation, wiring, skinning
Wiring the trailer interior
Before moving onto wall and roof insulation and skinning, you need to first run all the wiring or lighting devices that you intend to use. At the very basics, your wiring system should include:
- Interior lights for the sleeping compartment and the kitchen.
- Porchlight & exterior trailer lights.
- USB charger port.
- If the kitchen will have a sink, water pump wiring.
- RV battery wiring.
- USB charger ports.
- Battery charger.
After the wiring is completely in place, you may proceed to insulate the inside of the trailer. For insulation, you may stick to the material you used in the flooring, or use something else.
Styrofoam is rigid and thus easier to work with, but you will need to cut channels in it to allow wiring to run through. Conversely, fiberglass batts are softer and thereby get shaped in accordance with the wiring and other frame components in the way.
Some people prefer to use spray insulation, which is a quick and easy way of applying insulation. However, there are certain safety procedures you will need to follow – namely, you will need to wear safety glasses and a respirator.
In addition, spray insulation fills everything in its way, which will make it messier and more difficult to remove. This would be more or less big of a problem if you found out that you, for example, installed your wiring improperly and thus needed to fix it. We’d thereby recommend you to use spray insulation only if you are sure that you will make no changes to the wall and roof interior.
Skinning the interior
Once the insulation of the walls is done, you will need to skin the ceiling and the interior of the walls, including both sides of the galley partition. You should start with the walls since if you cover the ceiling, it will be difficult or maybe even impossible for you to pass wall covers inside the trailer.
So, you will need to first skin over the side walls, then the partition on both sides, and then the ceiling. When installing the ceiling, you will need to use the bows as guides.
Most people skin the inside of their teardrop trailers with plywood or 1/4-inch paneling. These will be flexible enough to allow you to curve them to match the desired shape of the ceiling. The choice of material will depend on your budget and preferences.
Insulating and skinning the roof
Once you skin the inside of the trailer walls and ceiling, you can install the roof insulation and then skin the ceiling.
Thanks to the bows installed earlier, it should be very easy for you to place insulation on the roof. Use whichever kind of insulation you’ve used at previous stages and whichever you are comfortable with.
After insulating the ceiling, place the outer layer of the roof on top of the bows. This layer should be wide in order to overlap with the walls and provide increased weather protection. To make curving easier, you may use the same 1/4-inch plywood you used for the ceiling.
Secure the roof in place by screwing it to the bows. After completing the roof, apply the same skin to it as you did with the exterior walls.
Once the outside framing of your teardrop trailer is complete, you will have to deal with the easier side of DIY trailer building – interior furnishing. If you don’t want to make furniture yourself, then the vast array of options available on the market should allow you to make a perfect interior for yourself.
You can give freedom to your imagination, but at the same time, you will want to design the interior in a way to allow it to accommodate the things you will be bringing along for your journey.
Here’s a couple of things to consider when designing interior storage space:
- You will need space for clothes, as well as space for dirty clothes that you’ve worn during the journey.
- You will need a place to store your personal toiletries.
- You will want some space for storing important camping items like flashlights and insect repellents.
The kitchen is another area where you may go in whatever direction your imagination takes you, so shaping and designing it will be up to you. However, we can pinpoint a couple of things that you should consider when building your trailer kitchen.
- Make sure to reserve space for your ice maker/refrigerator, including its handles and other protruding parts. In order to do this, you will need to know what ice maker/refrigerator you will use beforehand.
- You may want to add a couple of smaller shelves above the countertop for spices, tea bags, and other small items that you will be having with you.
- Your shelves should have a railing to keep items from falling off while you are driving.
- If you will have full-width shelves, you may want to partition them to make things more organized.
- Consider installing a paper towel holder somewhere to again keep things organized.
- If you are planning to equip your trailer with a portable camping stove, make a flip up stand or slide out for it rather than mount it on the countertop. This will allow you to save a lot of countertop space.
After you’ve built the core structure of your teardrop trailer, only a few finishing touches remain. Among them are:
- Installing doors and windows, which is rather easy, especially if you’ve bought commercially manufactured doors and windows.
- Installing trailer light kits and wheel fenders.
- Applying several heavy coats of urethane varnish on the outside to protect the trailer from moisture and rotting.
After completing the finishing touches, your teardrop trailer should be complete and ready for the journey!
If you’re interested in prebuilt teardrop campers, you can check out some of our recommendations here.