53' Box Trailer Conversion

[gearhead94]

Hey Everyone, I was wondering if anybody has any information related to converting/building a 53' box trailer in to a "camper". Is this allowed since its over 400 sq/ft for an RV. Has anyone ever built something like this. I have my CDL-A so moving it as a commercial vehicle would not be a problem for me. IF anyone could help me out with this or send me to the right places I would appreciate it.

 

[MnTom-FRF]

That might be a bit of a challenge to get into a lot of campgrounds, wouldn't it?

 

[Gordy-TC]

Go to Valid Manufacturing web site and click on "expandable trailer". I have seen this and man it is very trick (and built in Canada)

 

[gearhead94]

I race Motocross, so I would buy a trailer that has a roll up door and a lift and make that back 12 feet a garage to haul the bikes around. I would mostly go to wide open parking lots at the tracks. If I went to a campsite I would have to do my homework first to make sure I can fit in. Obviously I would need to get two campsites one for the trailer and one to park the truck, unless the site is large enough for both which is probably highly unlikely.

 

[qwcslvr1]

Gearhead, your project is very doable. We've done 4 different conversions of our own and are soon to start a 5th. Our smallest was a 50ft (the red one in the link) all others were 53'x102''. The current one we have is the white trailer with dual patios in the link below. That's also the one all the construction photos are of. We are presently in a paint and body shop getting a complete custom full body paint job. We use our conversions full time as we travel and manage motorsports facility's as a career. I'm sure you'll have lots of questions after you've looked through the photos in the link (694) of them! Haven't captioned them yet ,sorry. Be glad to assist with honest answers to any questions from a person that has really "been there, done that" and am going to do it again, LOL ! We are presently on winter hiatus so have plenty of free time. send me a PM and I'll send you my #.
Get a liquid libation as there are a lot of pics!
glad to help,
Patrick
https://rubickscubetrailerproject.shutterfly.com/pictures/8

 

[hot rod]

Most pull thru spaces are 70', so you are not going to fit on a site in most cases. And will be hard to get in, most campground roads aren't built to handle that kind of length. Also many campgrounds get real uptight about commercial looking rigs, we had a few not happy about our 40' living quarters race trailer. If you are going to fairgrounds, racetracks and the like, no problem. I have seen a few semi trailer conversions in blogs in the past when I was researching that sort of project, but it has been a while and can't remember where. The buildout would have similar issues to a box truck conversion, and there are a few of those build threads on this site. I think I would suggest something shorter than 53' to be more practical. We have a 36' toyhauler with a 12' garage and has plenty of living space, and the biggest toyhauler you can get is in the 44' range. Good luck!

 

[LargeMarge-TC]

1997 Ford CF8500 cabover registered as RV, towing a
1980 Utility 40x8 OTR reefer registered as RV.

We initiated this project with our REQUIREMENTS.

We need cargo carrying capacity far exceeding typical RV axles and tires and landing gear. According to the ID plate, our trailer is rated to twenty-seven ton... so we have that covered.

We need all aluminum, without wood walls or floor.

We need the structural integrity of a commercial chassis, without a mish-mash of plywood and staples.

We need to engineer and build the components into the design. This way, we can troubleshoot and / or isolate components while maintaining use of the rest of our home.

We need a vehicle with year-round capabilities. The typical RV is designed for occasional weekend use in moderate climes.

We have the capacity to carry around five ton of water.

With the PV system we designed and built, we are self-reliant. We have no need for RV parks.

Our favorite camp spots are in remote Baja. Drive out onto those perfect beaches, no other humans for weeks.

So, gearhead94, could a good place for you to start be your REQUIREMENTS?

 

[Mudcat-TC]

I converted a 53’ dry van into a custom fishing camp.

This is my YouTube site that shows from start to finish:

https://youtu.be/lxL2pjuMXGM


Any questions, you can reach me via email:

lm2facebook@yahoo.com

Lock, stock & barrel with stripped down 53’ trailer including everything what you see I have roughly $35,000 invested. All new full sized appliances and everything material wise was purchased at either Home Depot, Lowe’s, or my local lumber yard.

You can’t buy a 5th wheel for this price and have the room that I have. Sleeps 5-6 comfortably.

 

[TomRC]

Mudcat-that's a great fish camp. But with spring suspension and wood construction, the interior would fall apart quickly if taken on the road.

 

[Mudcat-TC]

I didn’t convert mine to use as a “traveling” RV. You’d be surprised how strong the sprayed closed cell insulation is and how it strengthened the entire trailer. I mainly converted mine to use as a stationary fishing camp with the intentions of if I “had to move it” then I could in case of a hurricane.

 

[danbru1989]

Mudcat-that's a great fish camp. But with spring suspension and wood construction, the interior would fall apart quickly if taken on the road.

I'm looking to convert a 48 foot for lots of traveling. What should I be looking for so it doesn't "fall apart"? Air ride suspension?

I was thinking wood framing like Mudcat's and pine boards (nailed and glued) for the interior.

 

[Mudcat-TC]

I’m definitely not a structural engineer. I never planned to use my conversion as a constant moving RV. I mainly built mine to be moved occasionally if need be in case of storms. However, I doubt that the wood would crack due to the fact that some regular RV’s have wood stud walls and spring suspension and I can assure you that with the sprayed closed cell insulation it’s much stronger than the RV’s you’ll buy from a dealership.

 

[Dragonslayer140]

Semi trailers are built to haul 30 tons or so of cargo for hundreds of thousands of miles during its life. The older spring style suspensions were set for maximum load, Empty they bounce down the highway like a paint shaker on steroids. I hated pulling empties back when i was driving. There is no way you are even going to come close to putting enough weight into the trailer when converting to an RV to cause the springs to flex enough to soften the ride. Wood construction, cabinets etc, are not going to live long in that environment. Probably not much issue for a fixed location use such as Mudcat's or if infrequently moved at low speeds and short distances.

A more modern trailer with adjustable air suspension will help greatly, especially in conjunction with rigid spray foam insulation, but only if being pulled with a tractor with air suspension also. I would glue and screw all my connections, and use glue on any plywood sheathing to help resist shear movement. Also seek out or build quality cabinets made from plywood, not transplants from an RV or Box Store chipboard cabinets.

Structurally trailers have quite a bit of torsional flex due to being a long empty tube, with a big hole in the end to load cargo. During normal use, cargo is loaded loose into the trailer any twisting that occurs during transport does not really get transmitted into the cargo causing any damage. When you start adding walls and securing cabinets to the trailer walls, that twisting and flexing transmits shear forces directly into those objects, i.e. it will try to rack the wall back and forth causing fasteners to work loose and wall paneling to buckle. The only way to reduce that effect, is to either allow some flexibility in the joints from trailer to interior walls using expansion joints which is difficult at best, or sufficiently brace the wall to resist the shear and reduce the amount the trailer flexes. Gluing and screwing plywood to ea. side of the wall under the finish is one way. Each interior wall added divides the trailer into smaller structural 'boxes' with the end result of each interior wall only having to carry portion of the total shear loading.

Lastly make sure you are aware of any issues with using a semi trailer as an RV in states you plan to travel to. Some states will not allow an RV with a semi style 5th wheel, some have overall length restrictions for RV combinations etc. of course if you plan on using a CDL and running under DOT regulations, then that's a different story.

Dave

 

[danbru1989]

Thank you, Dave! Your thoughts are very helpful. They address a lot of issues that I've wondered about a lot during my design stage.

My design has a good amount of interior walls, so I believe that the problem would be minimized by that alone. Plywood reinforcement on those walls will help. Maybe even some steal beams too. But I'll definitely look for a trailer with air suspension.

I know about length restrictions, but I've never heard of some states not allowing RVs with semi-style 5th wheels. I'll have to look into that.

Basically, I'm not impressed with the RV industry and how they build them. I'm convinced that I can build something much more durable from a 48' dry van – that will also match my budget.

 

[danbru1989]

Some states will not allow an RV with a semi style 5th wheel

Could you elaborate on that more? I can't find any info on it. Are you talking about hooking up your RV to a semi truck's original hitch? That's not allowed in some states?

 

[Dragonslayer140]

danbru1989,
I agree 100% on the quality of production RV's for the most part is seems the only difference from budget RV to top of the line is fancier finishes secured to same cheesy construction. I have toured many RV factories and quite a few custom truck conversion facilities, and hands down the custom guys build a superior product. With the quirky ideas and layout I am looking for its hard to find a company to build what I want for a price I can afford so I will be a self build project. I do have the advantage of working as a designer in the commercial modular building industry, and experience with fabrication, but still going to be a big project. Starting with an existing trailer will give you a huge head start, just remember the little trips to the box store for hardware will add up in a hurry, ask anyone one here that has built their own, plan on more time and money.. but you get the bragging rights of saying you did it your self.

I can not find the code reference for Washington for some reason, but when i was looking into rules for converting a commercial tractor to an RV, you had to have 4 out of 7 items that belong in an RV, i.e. fridge, running water etc, and the commercial 5th wheel plate had to be removed (OK to replace with a RV style hitch or goose ball) This was supposedly to prevent the truck from being connected to a commercial trailer. (Washington does have an antique truck registration which is exempt from CDL or commercial use, but I believe that the vehicle has to be on the way to or from some type of show.) I have seen several other states, UT, OH, NC that seem to follow the removal of commercial 5th wheel thinking. Florida I believe will not allow any type of hitch on a tractor conversion, motor home use only. There are some rules that are exempt if you are registered in a different state and just passing thru, but that does not mean you wont be stopped and harassed. The maximum length for trailer and combination are not subject to reciprocity, and you can be ticketed for being over length even if OK in your home state. The HDT guys have a website with listings for the requirements for converting a tractor to haul a fiver for most states State Listing of HDT Registrations | Heavy Haulers RV Resource Guide and Good Sam club has a site with listings for max trailer, combination and width for each state https://www.goodsamcamping.com/plan/SizeLimits.aspx Lots of states are 45 feet or less on the trailer, Good info on conversions for each state is hard to find, and most times the state agencies are not familiar with the rules themselves.

 

[danbru1989]

Thank you for all your thoughts on this! I did not realize that the removal of the commercial 5th wheel was required in some states. I’ll be checking that out for PA because I was thinking about pulling with the original hitch for a while until I could afford installing something more forgiving.

 

[Dragonslayer140]

Keep in mind, the king pin portion of both RV and semi trailers are pretty much the same size, although probably different material and capacities, but the bearing surface of the two are very different, the smaller diameter RV hitch is designed to support a pin weight of 3 or 4 thousand pounds, while the semi plates are designed to carry 50 thousand pounds or more. Rule of thumb is you can pull a RV with a semi style hitch, but not the other way around. RV hitches usually will tilt slightly left or right where semi hitches do not. If your state does not allow the big 5th wheel, you may have to look at finding a lighter trailer designed for RV hitch, perhaps something used for trade shows or light freight. would still be a stronger trailer than a manufactured RV, and still be a blank canvas for your designs.

Dave

 

[danbru1989]

Why exactly can you not pull a semi trailer with an RV hitch? Because it tilts side to side and runs a risk of not having clearance at the tires?

That's disappointing news... I was really hoping to use a standard dry van because they are readily available and I'm on a tight budget.

I guess that I could do a major conversion on the dry van to make it work. Notch out the front and install an RV hitch. Maybe?

 

[Dragonslayer140]

A lot depends on the weight of the trailer when finished and loaded with all the toys and camping paraphernalia you will haul. You will need to know gross overall weight, and pin weight (the amount of weight pushing down on the hitch). RH hitches have about a 8 inch dia. bearing surface (about 50 sq in) while Tractors have about 24 inches dia. (about 450 sq in) or 9 times the surface are to support weight. most semi trailers tend to have the rear wheels much farther back than on a RV trailer, this is done to increase the amount of legal weight that can be carried over bridges etc, by spreading the weight out. this results in a much higher percentage of the overall weight being placed onto the pin. As RVs are much lighter and do not have to worry about the bridge law, they tend to move the axles forward to both reduce the pin weight on truck, and to improve turning radius. Using a semi trailer which is longer than most RV and heavier interior construction methods, I think you are going to have far more pin weight than any RV hitch is rated for. More weight on a smaller bearing surface will also cause far more wear. I believe that the biggest hitch in RV style is 30,000 gross weight and 7,500 pin weight. If you can get within these limits it may work. Calculating finished weight of a project can be difficult. you will need to know the empty weight (and weight at the wheels and pin) of the trailer you will be using, then add in weights of building materials that are evenly spaced along the trailer (wall finishes, flooring etc) and then point loads of appliances and fixtures with their center of gravity. then you can assign a percentage of the weights to the wheel and pin based on their location. This will give you an educated guess as to what it will weigh. (its easy to forget how much fastener, little bits of steel etc add up. If your state will let you keep the commercial 5th wheel most of this becomes a moot point as you are unlikely to overload anything with that set up. (some states do hit you with a larger registration fee if you go over a specified weight limit) and make sure you can get someone to insure it. lots of threads on here about that...

There a lot of companies making mid-weight cargo trailers with either RV style hitch or goose-necks. A bit more expensive then a used van trailer, but still far more sturdy than an RV.

Definitely not trying to be discouraging, just want you to know to do plenty of research and have your ducks in a reasonably straight row before you create something you can't license, insure or isn't safe. Read thru the many threads on this site, there are several folks who have done a great job of documenting their builds and issues they have had. This group is a great bunch of folks and arguably the best resource you will find on this stuff.

Dave