Replacing plastic undercarriage sheeting...

[Cruiseomatic]

Needing to replace the undercarriage and can't see how to do it. Search online only brought up what to use as a replacement but not how to do it. I have 2X4's sitting along the frame above it and there is no room to move the sheet and also the mounting bolts on the frame ears. I want to replace the bolts anyway. How would I do this? I have a massive undercarriage and chassis repair projects that needs done including the tongue re-welded on level.

[Cruiseomatic]

Back to the undercarriage material, What is the best way to life the body only little over a 1/8"? I was thinking either shim the floor studs up enough every 4' or using 4 bottle jacks at the same interval. The body would be empty of everything to reduce weight and load.

[Cruiseomatic]

Bump...

[Cruiseomatic]

Not so much swollen, But if the house gets a tad off level is when it does it.

[westend]

Yeah, if you can feel the difference in height between what they repaired and the original decking underneath the vinyl, that is where the new and old meet. The original decking has swollen a bit with age.

You can check out the link in my signature, below, the Cowboy/Hilton. I restored an older Starcraft and pulled almost all of the old floor out. I also repaired framing and insulated everything. The whole restoration took about 6 months and I spent $5K. One of the better decisions I've had, the Hilton is better now than anything I could have bought for the price.

[Cruiseomatic]

Bump...

[Cruiseomatic]

The damage on this one was parallel with the wall above the fenderwell all the way to the back. You're talking about ripping everything out and replacing half the floor. The local shop said it would be more financially feasible and less labor intense to just replace what is bad. I do think however they screwed up because under the vinyl flooring, I can feel the new sheets meet the old flooring.

[BobsYourUncle]

The plywood floor really SHOULD be in one piece from side to side. These things rely on everything being intact and in one piece for structural integrity as it goes down the road. If you start piecing things in there, it loses a lot of this much needed strength.

As for jacking the walls up off the floor, it can be done in a couple of ways. But you do have to remove the screws holding the walls to the floor for a lot further than the repair area. This is to enable lifting the walls up to slide the new plywood in to the outside.
Really, you need to go all the way front to back and across the end to be able to lift it up enough to work on it.

I jacked the walls up off the floor form the ground outside. I put a 2X4 on the ceiling inside in the door area and put a couple 2X4's together on top of the jack and did it that way.
You can also put a 2X4 on the ceiling and jack it up from inside. as long as the 2X4 hits multiple roof framing members.

Then this will give you access to the floor under the walls

[Cruiseomatic]

Thanks for the detailed explanation. I have one that I know of hanging loose. Kicker is, It is not under the wall framing. Instead, Right infront of it. I don't know if the rest are like that though. I had two places that had to have floor repair and I don't think we ran the new sheets under the walls. I can always cut some pieces to fit under and screw them down. I have no way of lifting the body off the chassis. Would using leveling shims work if I used them as I move along? My plans are to strip this unit down to the framing and rebuild it. Starting from the bottom and working up. New flooring, wiring, plumbing, remodeling, installing a washer/dryer unit, dishwasher, new siding,insulation, etc... But I need to first make sure everything is secured to the chassis. The tongue needs re-welded because it is literally higher at the ball joint than where the chassis begins. I'm thinking if I can remove all the body bolts, I could shim the body high enough to slide a corriboard sheet through. Or am I wrong? I remember looking at your project a while back. You have some balls to take on a project like that. Seems like a lot of work and money for something that is waaaaay to far gone.

[BobsYourUncle]

After all that, I just checked and my website is down again.

I have a miserable time once in a while keeping it up and running. I'm running it off my home DSL connection and once in a while it goes down and i have a time getting it back up.

I'll work on it....

[BobsYourUncle]

Cruiso, I have done a total restoration of an old TT from the frame up. There is so much to detail about how they come apart, go together etc.

I can easily answer all kinds of tech questions about replacing anything, so feel free to ask.

In answer to your question here, the walls are typically held to the floor with screws. Before the siding or insulation is installed the walls are framed and lowered into place in one piece onto the floor, and then screwed to the floor with 2 1/2 or 3 inch wood screws. Then the insulation and the siding goes on, so it is a tough job to replace the bolts without taking a pile of stuff off.

The floor is built on a jig in one piece and lowered by a crane upside down onto the floor. They then drill the holes for the floor bolts through the frame ears, right through the floor and put the carriage bolts through and the nuts on the ears, cranking the nuts down until the top of the bolt is cinched into the floor plywood or OSB. Also at this time the tanks and various other things are put onto the underside of the floor.

Then the whole thing is turned right side up with a crane and the walls, partitions etc. are lowered onto the floor and screwed in place, The roof is built in one piece, upside down on a jig and it too is turned over with a crane and lowered down on top of the walls and screwed down from the top into the walls.

All this is done before any insulation, finish etc. Now I am talking wood framed units with fiberglass insulation here.

So as we now want to take things apart to fix them, you can see it becomes a challenge to get at the fasteners to do things like lift the walls off the floor. I did all that with mine. I lifted my walls off, rebuilt the floor, put in all new bolts etc etc.

As a suggestion, go to my website, link in my sig in the above post, and go through my picture horror story of my rebuild. This will give you an idea of how they are built and put together, thus also giving you an idea of what it takes to do things like replacing the bolts.

If your floor is not rotten and the bolts are intact, seriously, I would leave them alone. Spray some rust inhibitor on them to prevent more rusting. It is a lot of work to replace them.

If the bolts are loose and hanging below the frame ears, it means your floor is rotten in that area. This is how I tell if a TT has floor rot issues when I look at them - look for dangling bolts below the frame ears. If they are a bunch of pendulums, then the floor is rotten! Easy to tell!

Also, if the siding on the front and back is being crushed into the frame rails, it means the floor is rotten and sinking down, crushing the siding up where the frame hits it. This applies to front and back.

But you can lift the whole body off the frame without replacing the bolts. But only if your floor is intact enough that the carriage bolts don't spin out in the floor. You will have to remove all the nuts on the frame ears. AND the bolts on the frame cross members, which are typically lag bolt up into the floor framing. If you spin the bolt in the floor, then it will be a challenge to get the nuts off. but supposing you can get the nuts off with liberal application of penetrating oil to address the rust. The big thing is to make sure you don't crank too hard on the nuts. If they are tight, use oil to loosen them rather than strongarming the wrench. That will only spin the bolt in the floor. Remember, a carriage bolt only has a small square piece sucked into the floor to prevent it from spinning. Don't spin it in the floor!!!! Have patience, lots of it! Work the nut loose by going back and forth with the wrench and using lots of oil. Easy does it, go slowly! And minimum pressure! Once the bolt spins in the floor, good luck getting the nut off!

If you can accomplish this, then you can jack the trailer up off the frame to allow the belly skin replacement in one piece as it should be. You'll have to drop your holding tanks and various other things that go through the floor but I can explain how to do that too.

Hope this helps!

[Cruiseomatic]

I've seen some of them and they're in bad shape. Spent time in LA and not stainless or galvanized so saltwater air and humidity got to them. Before I remove the siding, How are the walls typically held to the floor? Got to thinking, Once I get everything in motion to do a build thread. My biggest two challenges are replacing the undercarriage plastic material with corriboard and the plastic roof with aluminum.

[BobsYourUncle]

Replacing the bolts is a big job. They are typically carriage bolts inserted from the top of the floor down through the holes in the frame ears.

Challenge is, the floor is bolted to the frame BEFORE the walls are put on. So to get at the top of the bolts, you have to remove part of the wall in that area.

What is the purpose of replacing the bolts?

[Cruiseomatic]

You're a good guesser. Since I want to replace the mounting bolts once I figure it out, I was thinking with the bolts gone, To use leveling shims between the 2X4 and frame rail to "lift" the floor and slide sheets of corriboard between them. Repairing the current is almost impossible. Possum decided he didn't like it and shredded it pretty good. Not to mention, There is almost no insulation in the floor both from factory and what that little ....... took. Its also bunched up front and back from factory and looks like it can hold water.

[opnspaces]

Are you talking about replacing the woven looking plastic sheeting that sits on top of the frame rails and under the floor? Or are you talking about replacing the Coroplast (plastic cardboard) under the frame rails?

What are 2x4's are you talking about pieces of lumber, pieces of steel, or is the plastic in 2 x 4 foot sheets?

On a guess I'm assuming you are talking the woven plastic that is sitting on top of the frame rails. If that is so, the entire trailer is probably sitting on that plastic. You're going to have to find a way to unbolt the trailer from the frame and lift it enough to remove the plastic. You might be able to lift small sections and slide the plastic under but it will probably be near impossible to get it on smooth and unwrinkled.



You might consider just removing the plastic with a razor knife and doing the required repairs. Then have the underbody coated in spray foam by a contractor and skip replacing the plastic.

Good luck with the project, it doesn't sound like fun by any means.