HDT with HD Trailer

[Nwcid]

Is there much information out there about DIY converting semi trailers to RV's?  

I figure if you are going to have a HDT why not add a worthy trailer.  I have spent some time on google and most information just leads back to the companies like that make them for prices that are way out of my budget.  I did find, https://www.truckconversion.net/forums/ but most of their material is very dated.  

I figure for the price of buying a 40-45' 5th wheel toy hauler, I could build a custom trailer that would be more durable for the same or less money.  It would also be built exactly how I wanted it. I think 53' might be a bit long, but I do see they make 43' trailers.  This would give you the same overall footprint as a large toy hauler. 

 

Edited September 5, 2020 by Nwcid
Added "DIY"

[Larry Burkett]

Have you checked out Spacecraft RV, they build trailers like that.

 

spacecraftmfg.com

 

 

[Nwcid]

6 minutes ago, Larry Burkett said:

Have you checked out Spacecraft RV, they build trailers like that.

 

spacecraftmfg.com

 

 

As I said, I can find companies that make them.  That is not what I want.  I am looking for DIY resources. 

They make an amazing unit, but I am not shelling out $250,000

[Steve from SoCal]

30 minutes ago, Nwcid said:

As I said, I can find companies that make them.  That is not what I want.  I am looking for DIY resources. 

They make an amazing unit, but I am not shelling out $250,000

What resources do you have to build a trailer?     

I have a project kinda like what you are talking about.    The development is mostly complete, I haven't done any work on the trailer except to build a ramp door for the back so far.    I need to use the trailer to move a house full of stuff before I begin the construction.

 

Steve

[Nwcid]

2 minutes ago, Steve from SoCal said:

What resources do you have to build a trailer?     

I have a project kinda like what you are talking about.    The development is mostly complete, I haven't done any work on the trailer except to build a ramp door for the back so far.    I need to use the trailer to move a house full of stuff before I begin the construction.

 

Steve

Lots of space.  Lots of construction background and experience.  I have resources to help with the metal work. 

My concerns are overall structural integrity, adding slides outs, height as they are 13.5' high before adding roof accessories, just overall unknown thing to look out for that I have not considered. 

 

[Steve from SoCal]

Commercial van trailers are built very differently than a camper/RV 5th wheel.     When you cut an opening for a slide the wall has to be reinforced along with the floor/roof.     Weight of materials and weight distribution both along the trailer and side to side are important.      

Don't buy a trailer with a translucent roof or panels.    Sheet and post trailers are the most common and easiest to modify.     Fifth wheel plates are a high wear item on commercial trailers, they can be costly to replace.     You most likely want a drop frame van, Kentucky and Stoughton are the best starting points.

 

Steve  

[Steve from SoCal]

Here is the only mod I have done to the trailer yet, a ramp rear door to load cars. 

Steve

[rickeieio]

Look on racingjunk.com.  Many trailers already converted, but would likely still need some work.

Be aware, in most states, an RV single piece can only be 45' long, and 65' in combination. And 13'6" is legal height almost everywhere.

I'm not saying there aren't a couple of us over 45' with a trailer, or over 65' combination.  But you must choose how far you're willing to push it.

[Nwcid]

11 hours ago, Steve from SoCal said:

Commercial van trailers are built very differently than a camper/RV 5th wheel.     When you cut an opening for a slide the wall has to be reinforced along with the floor/roof.     Weight of materials and weight distribution both along the trailer and side to side are important.      

Don't buy a trailer with a translucent roof or panels.    Sheet and post trailers are the most common and easiest to modify.     Fifth wheel plates are a high wear item on commercial trailers, they can be costly to replace.     You most likely want a drop frame van, Kentucky and Stoughton are the best starting points.

 

Steve  

Yes, that is why I am asking the questions now.  I know they are not built the same and any time you cut a hole in a structure you need to make sure it is properly constructed.  

With the trailers already being 13.5' high it might need a roof chop to install utilities on the roof. 

I am starting to look at the different shapes/makes of trailer.  The lower, within reason, the back is, the better.  I will be making a toy hauler out of it, I also do not want it so low I can not take it where I take my current toy hauler. 

 

[Nwcid]

11 hours ago, Steve from SoCal said:

Here is the only mod I have done to the trailer yet, a ramp rear door to load cars. 

Steve

Awesome.  A rear door will be a must for me.  I am making a toy hauler. 

 

[Nwcid]

2 hours ago, rickeieio said:

Look on racingjunk.com.  Many trailers already converted, but would likely still need some work.

Be aware, in most states, an RV single piece can only be 45' long, and 65' in combination. And 13'6" is legal height almost everywhere.

I'm not saying there aren't a couple of us over 45' with a trailer, or over 65' combination.  But you must choose how far you're willing to push it.

I forgot about them, I will check it out. 

I dont want a 53' trailer.  It looks like there is a standard 43' version.  This should be shorter then hooking a 43-45' toy hauler being pulled by a HDT due to where they hitch. 

[rickeieio]

Which could also nearly eliminate hauling anything on the truck deck.  Decisions......

[Nwcid]

34 minutes ago, rickeieio said:

Which could also nearly eliminate hauling anything on the truck deck.  Decisions......

True, but the "garage" in this would be able to support vehicles that a traditional toy hauler could not.  Building a 43' trailer would give me a similar layout to what I have now, but a 15' garage. 

A 48' box might be nice, but then it starts getting long.

 

Edited September 5, 2020 by Nwcid

[Steve from SoCal]

6 hours ago, Nwcid said:

Yes, that is why I am asking the questions now.  I know they are not built the same and any time you cut a hole in a structure you need to make sure it is properly constructed.  

With the trailers already being 13.5' high it might need a roof chop to install utilities on the roof. 

I am starting to look at the different shapes/makes of trailer.  The lower, within reason, the back is, the better.  I will be making a toy hauler out of it, I also do not want it so low I can not take it where I take my current toy hauler. 

 

Regarding openings, when you cut a section of skin and ribs, doubler plates are used to strengthen the surrounding area.      Large openings <4 feet need bracing in the roof rails and possibly straps under the sill.     That is in addition to the frame that would define the opening.   

All the full height trailers are 13' 6" high, very few states east of the Rocky's allow trailers higher than this.     I would suggest that you make no protrusions through the roof.   

There are several types of drop frame van trailers, some with 22.5 wheels, 17.5 and a few with 19.5.     A single drop, one with just a simple offset of the body behind the "gooseneck" will be 114~119" high with 22.5, 125~126 with 17.5      The single drop trailers would have at least as much ground clearance as a raised 5th wheel.     A double drop trailer would have "dog houses" or wheel boxes inside the back and be much lower.    

Finding anything shorter than a 48' trailer is going to be an older trailer or purpose built.     Your best option is to get a 53' most common newish size and shorten it to length.     A 53 cut down to a 43 would have the rear axle at the very back of the trailer.

 

Steve    

[lappir]

3 hours ago, Nwcid said:

True, but the "garage" in this would be able to support vehicles that a traditional toy hauler could not.  Building a 43' trailer would give me a similar layout to what I have now, but a 15' garage. 

A 48' box might be nice, but then it starts getting long.

 

Many have "thought" about do in a conversion and a few have actually completed one. 

First issue to me is the wheel placement. Most flatbeds or drop decks have fixed tandems well back on the trailer. It would make maneuvering in "Campground" difficult. Most 5th wheels and bumper pull trailers have close to "Mid" placement of the axles.  

Second is the height of a "Van Box" from the ground. To have a flat floor it will be above the wheels which can be near 40 inches off the ground. My Spacecraft is that way.

I discussed having a "Garage with a lower floor behind the axles, but it would have been a "First" in a different way than the "other First" they tried for a trailer a bit before mine was built. There were some issues and I'm not sure how they were resolved. The original owner sold the trailer fairly quickly and the second owner tried to say it was the fault of "Spacecraft".  Spacecraft had changed ownership I think before the second owner made it to the "Factory". 

I put a side door into a box I used for a while on my truck. It worked out OK, but I'm glad it's no longer on the truck and has a new life as just a storage box. It started out as a 15' box, I had it cut down to 10' 6" before putting the side door in with the help of a cousin. We cut down a "door panel" or "Blank" that is made for the swinging rear trailer doors. Added some large "Gate" hinges and then just used an inside securing  to keep it closed. I had the roll up door at the back which allowed me to open the door from the inside. I really like my latest box that had swinging doors on either side. No wasted space up high where the roll up door used to be. 

I had nothing put on my roof. I started out with the Coleman Mach basement HVAC system which is totally junk. I had a retrofit of a LG Mini Split system which was very costly, but is working very well. Time will tell if it was a good investment. The first one certainly wasn't. 

Next you have to think about if you are going to do "Pop Outs" or "Slide outs". What are you going to use for them. Hydraulic, cables, worm gears, or something totally different? How will you make sure they don't leak?

Spacecraft builds almost everything from the axles up. New Horizons will not yet do the air ride tandem 25k axles and may never do it. There is another company in Iowa that builds big trailers, but the name escapes me. A few have had them build one for them, but I haven't personally seen one. And yes, there is Racing Junk. They are build for the purpose of moving cars, tools, replacement parts and maybe offer a person the ability to clean up and take a nap. I haven't seen one that I thought I could live in. 

Those are my thoughts after trying two off the lot Toyhauler's and my one custom build Spacecraft. I did search high and low for an alternative, but didn't find one. 

 

Rod

[Nwcid]

Right now with my toy hauler I am 38" off the ground for my garage, so that is really no different.  

In theory one of the lift gate stacker trailers would be an awesome base to start from.  You are right, they are not set up for RV life.  

Finding an appropriate HVAC system would be a challenge.  

I would absolutely add 2 or possibly 3 slides.  They would be framed, sealed and powered the same way a traditional RV is.  I know there are 3 different main systems. 

 

[rickeieio]

Several years ago, I stumbled upon a trailer on racingjunk that I would have snapped up, but DW, aka CFO, said no.  It was 48' spread axle with air lift on both axles.  Best part was, the front axle could be over extended to go over curbs or shorten the turn radius.  It was a race car hauler with stacker and full living quarters in front, recently re-furbished.  But, it was in New Brunswick, CA, and asking price was near $100k.  I thought it was a bargain, but the bride wasn't ready.

You'd be hard pressed to duplicate it for twice that.

[Ray,IN]

13 hours ago, rickeieio said:

Look on racingjunk.com.  Many trailers already converted, but would likely still need some work.

Be aware, in most states, an RV single piece can only be 45' long, and 65' in combination. And 13'6" is legal height almost everywhere.

I'm not saying there aren't a couple of us over 45' with a trailer, or over 65' combination.  But you must choose how far you're willing to push it.

How about a super C 52' long. http://powerhousecoach.com/construction.html  click used bar for picture.

[Nwcid]

5 minutes ago, rickeieio said:

Several years ago, I stumbled upon a trailer on racingjunk that I would have snapped up, but DW, aka CFO, said no.  It was 48' spread axle with air lift on both axles.  Best part was, the front axle could be over extended to go over curbs or shorten the turn radius.  It was a race car hauler with stacker and full living quarters in front, recently re-furbished.  But, it was in New Brunswick, CA, and asking price was near $100k.  I thought it was a bargain, but the bride wasn't ready.

You'd be hard pressed to duplicate it for twice that.

Sounds awesome.  I am still in the planning phase, next is the convincing phase 😉

[Nwcid]

5 minutes ago, Ray,IN said:

How about a super C 52' long. http://powerhousecoach.com/construction.html  click used bar for picture.

The "motorhome" layout does not fit out needs well.  They do have some cool design ideas though. 

 

[rickeieio]

9 hours ago, Ray,IN said:

How about a super C 52' long. http://powerhousecoach.com/construction.html  click used bar for picture.

There's only a hand full of states that would be legal in if registered RV.

[Ray,IN]

3 hours ago, rickeieio said:

There's only a hand full of states that would be legal in if registered RV.

Yet the company is located in Idaho.

[rickeieio]

And Idaho is not one of them.

https://www.rvtripwizard.com/rv-info/state-road-laws

[noteven]

I think the famous Powerhouse Coach rig is operated under an annual ID state permit. 

[Exile]

Drop a container onto a tandem gooseneck flatbed.  Pick a length, chop the container to fit.  Cut big holes in it, easy to weld reinforcements. Cheap and everywhere.  Sell it as a tiny home when you’re sick of it. Low enough to mount a/c on the top.