Anyone Ever Converted a Semi Trailer...

[TBiglug]

I'm looking at building a custom trailer this year and was looking for ideas and advice from the experts. Base of the conversion will be a 45' drop frame van trailer. May do a 48' or 53' depending on what I can get the best deal on. Would like to stick with 45 for a little better maneuverability. Front 20' as a living quarters, rear 25' convertible for hauling horses and plows or my car/ truck when we go visit our daughter in TX. Laid out a couple base plans already, working on gathering information for the specifics and details.

1. Has anyone ever lowered the roof on a semi trailer? Would like to go to 12'6 instead of 13'6 for overhead clearance and to keep under the height laws for mounting a rooftop A/C or solar panels.

2. What's the best way for tying in the interior wall framing to the outer skin for strength? Assuming trailer will be FRP sided. Interior wall framing will be 2x2's for outside walls and 2x4 studs for interior.

3. What type of insulation do you recommend for the walls? Regular rolled like in a house, foam board, or something else.

4. What is best for the paneling on the inside? Thin sheets or something heavier like 1/2" plywood for strength and secure mounting of cabinets. Weight shouldn't be an issue. Trailer will be being pulled by a semi tractor anyhow. Just a matter of singles or tandems on the truck. I'll use one of our farm trucks to tow it around initially until I decide on a permanent toter. Most weight it will have (aside from permanent structures inside) will be 4- 2,200# horses, 1- 600# plow and 500# of misc. equipment in the back. Or one 8,000# truck. This will not be used for for-hire general commodity trucking. Just RV'ing and going to horse pulls/ plow days.

5. Anyone ever build "ramp doors" on a trailer before? I want to make the rear door a 9'6x7'6 ramp for loading and unloading horses or vehicles and a 9'x4' side ramp for loading and unloading horses and the plows.

I'll start there. Trying to keep it under 5 questions at a time, lol. There will be more to come. I'll try and find some pics of the plans I hand drew out and see if I can get my 3D rendering from SketchUP to a format I can share so you all can see where my mind is going.

Thanks for the help to come.

[Dave Glennon]

Not exactly a conversion of a semi trailer, but we built a semi trailer about 4 years ago. We went 48' long (wish we would have gone 53') x 13'6". Front 12' is a lounge area with bunk beds and bathroom with shower and stool.

To try and answer a few of your questions:

2. Our interior and exterior walls are 2 x 2 square tubing. They were all welded
3. Insulation - we used rigid foam. If I had it to do again, I would have the trailer spray-foamed. I know it is more expensive, but believe it would be a better end result and tie everything together. We have .040 aluminum skin attached to the 2x2 tubing
4. Interior paneling - I tried to show some pictures. We have a variety of finishes. In some places there are cabinets, and the walls are unfinished behind there. Other areas we used the white aluminium and upstairs we used 1/4 luan plywood behind the indoor/outdoor carpet.
5. Ramp door - we constructed our own. There are 100 different ways to do the hinge and latches. We ordered some "airline" handles and latches from Featherlite and are pretty happy with those. The hardest part is getting the spring wound and set properly.

If you have plans drawn up, you are far ahead of where we were! We looked at a lot of different trailers at the races and took alot of pictures. It was a trial and error process, however.

As I'm sure someone else will advise you, there are tons of trailers for sale on racing junk, Hoseheads, etc and you can often find these at a steal of a price and put some work into them to update how you want. We had about 5 years of time (on and off around winters, racing seasons) to build ours. Always costs more and takes more time than originally planned.

Let me know if I can offer any other help - good luck!

[hot rod]

Big- welcome to the forum, you'll find plenty of helpful folks here.

Dave- Wow! Impressive trailer build. That thing looks better than most of the factory units out there, and I guarantee they aren't built as strong as yours. My rule on buying a trailer: figure out exactly what you need and then add 4'. You'll never regret it.

[TBiglug]

Thanks for the help so far. here is the basic plan I'm working off of now. I'm sure this will be a long term build. Hopefully I can find a trailer in the spring then just park it next to the house and work on it as I get the time. This is the 45' setup. If I did a 53' I can add the extra 8' onto the living quarters area. I'm starting to love Google SketchUP. I've been building a new doghouse based off of the model I made for it the last couple nights.