How to Build a Trailer? Key Tactics The Pros Use For Building Trailer

Today, it’s convenient to buy pre-made products such as trailers, but you just feel more fulfilled upon seeing one and being able to say “I built it.” For businessmen and travelers, the utility of a multifunctional trailer is unparalleled. And for those who want to learn how to build a trailer themselves, this can be a simple task upon using this guide.

Frankly speaking, there is nothing to be afraid of when building a trailer. The trailer consists of a basic structure, and although it involves some mathematical operations, it is certainly not rocket science. So do relax and don’t feel that you need to call a skillful college graduate for advice on this. In this guide, we have introduced some very basic knowledge to help you move forward quickly.

The trailer is suitable equipment for various applications, from hauling your tools to the job or your gear to the campsite. Whether you plan to build a trailer for your business or occasionally need a trailer for family camping, this article will provide you with the information you need to build your trailer!

Things You’ll Need to Build a Trailer

When working on how to build a trailer, you will need some tools. Without the tools, you cannot build your trailer. If you have these tools already, then it’s good, and if not, get them right now and start building your trailer. We have picked the best products and recommend here to don’t have to find it online or go to any shop. Get them right now and start building your RV. Get the following:

  • Six plates 12 meters long, pressure-treated
  • Two trailer wheels with 60 feet 2 by 2-inch angle iron in 12-foot sections
  • Two by a 12-inch mounting, trailer axle with suspension
  • A 12-foot section of 2-by-4-inch square steel tube

Welding Gloves

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Trailer Lighting Kit

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Welding Helmet

[amazon box=” B00R2DUWOM”]

Framing Square

[amazon box=” B086R74VLK”]

Digital Laser Tape

[amazon box=” B07MP1JB2Z”]

Trailer Coupler with a 2-inch Channel

[amazon box=” B0007LZGXS”]

Alternative Saw with a Metal Cutting Blade

[amazon box=” B00008WQ38″]

Trailer Wiring

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Galvanized Transport Screws

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[amazon box=” B00IJ0ALYS”]

Metal inert Gas Welder

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Forming the bottom part of the trailer 

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How to Build a Trailer Step By Step 


Place the angle iron on an even surface and place the two 12 feet parts 6 feet away from each other, while the iron’s angles are facing each other. Use a metal saw to cut a notch of 45-degrees at all ends of the 12-foot lower lip sections. These parts will make up the side railings of the trailer.


Cut two 6-ft angle irons and place one on all ends of the 12ft section to make up a rectangular shape on the floor. Using a jigsaw, cut the same 45-degree angle petals from the two 6-foot-long ends to fit the 12-foot-long section. Using a square, make sure the 6ft and 12ft parts’ angle is 90 degrees, then weld all the corners in place. When it is determined every corner is perfectly aligned at 90 degrees, the final welding of all the trailer’s corners can then be completed.


Rotate the frame to make the flat portion of the angle iron to face upward. Cut three more angle irons with a length of 6 feet and place them as keys every three feet, while measuring the gap around the 12-meter-high side rails. After ensuring that they are at a 90-degree angle to the 12-meter-high side rails, weld them in place.

Read More: How to Clean the Outside of a Camper Trailer

Assembling the Axle and Tongue 


Cut out a notch of 2 inches in the middle of the foremost iron bracket so that the 12ft-long square steel part is comfortably installed on the trailer frame’s bottom. The preceding brace located at the front part of the trailer shouldn’t be cut off. Put the square steel into the notch, then place it tightly on the next angle bracket. Do make sure that the tongue is placed at an angle of 90 degrees to the trailer, then go ahead to affect the welding at the spot in which the three points touch the frame. Failing to guarantee that the tongue is seated at a 90-degree angle will give rise to the trailer’s inadequate control during the driving, which may result in an accident.


Measure through the front to the rear end of the trailer, 7ft on all sides, and put the center portion of the axle there.

Take adequate measurement of all the rear points and front axles of the trailer to guarantee proper installation, then weld them or fix the spring suspension bolts in place. 


Install the tires of the trailer, and then turn over the entire trailer. 


Install the coupler lighting and floor


When necessary, install the trailer’s hitch by drilling a square steel pipe and secure it firmly in place with screws. You do not need to weld at this point, as the coupler could be damaged in the process of usage.


Connect the light to the trailer’s rear through a square tube. Set up the brake lights and side position lights, and then connect them properly according to the instructions on the trailer light packaging.

Step-10 Use galvanized transport screws to install the pressure-treated floor on the trailer.

Read More: How to Build a Lightweight Truck Camper

Frequently Asked Questions  

Is it cheaper to build a trailer?

how to build a trailer

Usually, we feel that building a trailer is cheaper than buying it. Cost is also one of the important reasons why people want to build trailers. Generally, we believe that the construction cost is lower than the purchase cost. Really?

Almost all new trailers you see in many places are factory-made. These factories purchase their materials (steel, aluminum, etc.) at very low prices because of their large purchases. They can also use these materials more efficiently because they can build many trailers, so there is not much waste per unit. For axles, wheels, tires, hooks, bolts, and other parts, the same pricing applies.

In all, considering the materials, parts, time to manufacture, build, paint, and the cost of additional tools you buy, the cost of building a trailer may be higher than the cost of purchasing. If you are working on building a trailer park, the costs would add up as well.

How can I make my trailer longer?

Sometimes the trailer is not long enough. A 6-foot trailer cannot comfortably carry 8-foot-thick plywood or wall panels or frame wood, or various other objects. It is possible and usually easy to “trade-in” to replace a shorter trailer with a longer one, but this is not the choice of every house, farm, ranch, or a business owner. An extended trailer may be the only option. This can be done, but it requires welding equipment and professional knowledge, and strict mechanical skills.

Step 1

Plan the trailer expansion carefully. Don’t just add a few feet at the end. The trailer must be balanced to ensure safe and efficient operation. It is planned to increase by one foot for every foot extended backward. Calculate new braces and longer yokes; an extension may change the turning ratio. Examine existing frames to determine the size and type of metal frame; some trailers use angle irons, some square tubes, and some U-shaped grooves with one side opening.

Step 2

Remove all wiring from the floor and tail lights and brake lights; keep the wiring to install replacement parts. Purchase new steel to match the existing frame; get more sheets and braces. Measure the frame and mark points to install the extension. Buy some thin steel plates or strap steel for gussets or reinforcement for new joints.

Step 3

Use an angle grinder, metal saw, or welder’s torch to cut the frame at the marked position. Support the trailer so as not to remove parts without tipping over. Set the removed end aside. Using an angle grinder or welder’s cutting torch to cut its welded joints on the frame, remove the existing fork frame at the front.

Step 4

Measure and cut the extension frame. Clamp it in place with welding tongs, and then weld it to the existing frame at both ends. Cut the steel plate or strap steel and weld it under the new joint for additional support. First, weld the back extension. Remove the yoke completely from the front, then weld the extension to the frame and add support underneath.

Step 5

Replace the fork frame. If it is possible to solder back the existing one, please use it. Make a new fork or extend the old one to weld the fork’s rear end to the frame in front of the axle spring hanger. Extend the existing fork frame by replacing the triangular part or removing the hook ball cover and welding on a single extension line and replacing the hook ball cover. Weld the cross brace or triangular gusset where the reinforcement is added.

Step 6

Install a new floor and replace the brake wire and tail light wire harness using new wires or connecting old wires with crimping. Wrap all wire connectors with electrical tape to seal them.

How do I make my utility trailer wider?

If the entire utility trailer needs to be wider, just perform the following steps:

Separate the trailer from the middle (front to back). Cut all the beams and add the middle part.

Ensure that the beam is quite strong enough to accommodate the new width. Longer beams must be stronger to withstand the same load. The material will make a difference.

If only the existing beams are connected, the new additional parts must overlap to obtain a good firm weld after cutting.

Create a new “flatbed” trailer bed. Make sure that the new beam is straight, square, and flat when making beam connections. Skills like cross members are very suitable for building a flatbed trailer as well.

How much does it cost to build a cargo trailer?

A cargo trailer is a rectangular box with a top plate and four sides, mounted on one or two axles. The enclosed area’s height may only be 4′-5′, but most are 5.5′ or higher. To build a single-axle enclosed cargo trailer, it is expected to cost around $1,000-$4,000. It also depends on the size and building materials and additional options such as dome lights, power outlets, or additional doors or ramps.

How do you turn a utility trailer into an enclosed trailer?

how to build a trailer

A ready-made enclosed trailer will cost more than $1,500. In contrast, you can make an enclosed trailer for a little fraction of that price, upon utilizing a utility trailer. The door can be handmade with bolt handles and locks.

To turn a utility trailer into an enclosed trailer, determine the size of the enclosed trailer, and then obtain the utility trailer closest to that size. You will need to construct the trailer’s sides to fit the existing mounting slots of the utility trailer and wheels.

Next, take a proper measurement of the utility trailer to get the actual center. Next, put the axle in the center area of the utility trailer. Install the tongue on the crossbar aligned with the axle. The tongue is triangular, and the trailer is connected to the transport vehicle by ball bolts.

Turn the utility trailer over and fix the tongue on the crossbar with screws and bolts. Fix the latch in the center of the trailer. The latch will keep the trailer balanced during movement. The hole at the tongue’s edge will be connected to the transport vehicle’s rear by a movable ball bolt.

Now What! Well

Cut five pieces of plywood on the four sides and top of the trailer. The trailer’s angles and sides can be nailed with liquid solder to stabilize the plywood and serve as a rigid foundation for the top of the trailer.

Before installing the floor on the trailer, use a utility knife to cut the polyethylene trailer floor to a certain size. Polyethylene will provide traction and weight to your trailer floor. Use nails or rivets to pin the edges to prevent curling.

Coat the outside of the finished trailer with a soft aluminum plate, one on each side of the trailer, and the roof. Fix the aluminum plate with nuts and bolts, and press the edges to make the trailer airtight.

Install the trailer license plate and light bracket at the back and side of the trailer. The spacing of the sidelights should be 12 inches and should be smaller than the standard tail lights. Install traffic tail lights and fix them with bolts and screws.

How long should a trailer tongue be?

The general rule is that the trailer tongue’s length should be twice the distance between the wheels, so the force from acceleration and braking will be distributed along with a slender triangle. This arrangement reduces the tendency of the trailer to turn from one side to the other.

Most states have also established regulations that stipulate the maximum length of the trailer tongue, with a standard of six feet. Long tongues can be harmful to other drivers who are not used to following articulated vehicles in corners or parking lots.

How do you modify a utility trailer?

To modify the utility trailer, cut out the frame, and insert the required part. Next, continue to add other modified materials on the front and back. Finally, weld them together again.

Do cargo trailers hold their value?

Yes. Cargo trailers are usually made of highly durable materials, so they can maintain their value for a long time. This also ensures that they do not have too many problems.

Does anyone rent trailers Besides U Haul?

Travelers who plan to go on a weekend journey or take a vacation of several months can rent a trailer to haul motorcycles, boats, or cars. They can result in renting a pop-up tent trailer for their fun trips or rent a cargo trailer with enough household items and personal tools to turn an unfurnished house into a comfortable home for long-term living. They can also rent a utility trailer from sources other than U Haul, such as:

  • Sunbelt Rentals
  • Budget Truck Rental
  • Penske
  • Tow Dolly Rentals

What is enclosed trailer walls made of?

Most enclosed trailers will use aluminum, galvanized steel, sometimes called galvanized sheet; or FRP. For wall beams, steel or aluminum is used. Fixed to the beam is plywood, aluminum, or a combination of them. The most commonly used is aluminum exterior.

How do you frame a tiny house on wheels?

The trend of tiny houses on wheels has swept the Internet and our hearts. If you desire to work on how to build a trailer house or tiny house on wheels, use wood with a shape suitable for a flat floor, and use metal brackets to fasten it.

You need to wrap the frame in plywood (or you can use OSB-it is equally durable). Don’t skimp on the metal bracket; you shouldn’t be worried about the finished house’s aesthetics. Once the house is covered, the metal supports will be invisible, and you will know 100% that your project will not collapse.

Final Words

In conclusion, a trailer stands as a great tool which can serve its owner in diverse capacities. Furthermore, for those who desire to work on how to build a box trailer, the steps highlighted above would act as a sure aid.

Alix Johnson Romi

Alix is the Co-founder of Easy Trip Guides. She started with Michael to share her love for the outdoors with people from all around the globe. She started as an outdoor lover while skiing and snowboarding in the backcountry of New Zealand with her future husband, Antonio. They shared a dream to see the world, so in 2013 they set off to cycle from California to Argentina. The freedom of the open ice route, living close to nature, and the total annihilation of her comfort zone fueled Alix's desire to keep exploring long after the bike trip was over. Her adventure addiction has taken her scuba diving with hammerhead sharks, hiking to the K2 base camp, kiteboarding in Sri Lanka, and kayaking in Antarctica. Through these experiences, she has developed a strong belief in the power of adventure to reconnect people to nature, provide meaningful jobs to impoverished communities and promote the conservation of wild places and animals. At Easy Trip Guides, she covers snowing, skating, snowboarding, and skiing as she loves to do these outdoor adventures a lot.

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