Question to all those that have done major camper rebuilds

[JoeChiOhki]

My old KIT is need some major repairs this spring/summer and since I will hopefully have a barn to do the work in, I'm plotting to do some major structural overhauls to my camper to fix some issues that have been around since I first bought her.

One of the issues is that the floor in the rear overhang sags rather badly, mainly due to the poor design by KIT.

I want to drop the holding tank, and rip the entire floor off the unit and build a new one that's alot beefier than the original.

My big concern is that in order to do this, I will need to jack the unit up with the bottom unsupported to remove the floor, and I am concerned if the camper will stay together once the floor is pulled while standing on the corner jacks.

Anyone with advice on this, I would greatly appreciate any tips or foresight on safely pulling the floor.

[JoeChiOhki]

67avion wrote:
I think it was page 198 on the Avion thread. Scroll down.

That's the A-frame support through the roof, was that what you were referring to?

Hey, here's a side question for those that have made wheeled platforms with casters, what's a good model that will stay put attached to a 4x4 post and support a camper?

I've got a slip in a barn that's not a whole lot bigger than the camper itself, so being able to shift side to side for ease of working will be helpful, but not mandatory.

I can't do any work outside, I'm not allowed by park rules to do major rebuilds out in the park, but I can do it with it stowed in the barn, which will allow me to do the restoration on this 40 year old camper.

[67avion]

X2

[Joe417]

I've never pulled the floor completely out of one so I'm not an expert, but many of the older campers rested on jacks that were fastened under the wings of the tub. Electric corner jacks were a luxury. 2x supports under the wings in addition to the corner jacks will support it while you remove the floor.

You said that you were concerned that the sides may spread once the floor is removed. I used 2 Erwin 50" hand clamps a couple of weeks ago to pull the tub walls together while removing the cross braces to have them re-welded. Since your jacks are on the corners and you aren't working with a rot condition, the end walls should hold it together.

You mentioned beefing up the floor. In addition to increasing the truss thickness a little and using only plywood(no particle board), something I really like for additional strength at very little cost or weight, put in structural foam board between your truss members and bond both sides with polyurethane adhesive. It is very strong. My previous TC was a Palomino and the camper was made that way with only 1/8" skin. Test it out on some scrap plywood and you'll be a believer if you aren't already.

I think your biggest problem will be trying to recover with all the aches and pains after you crawl around for several day under your camper. It was for me.

My best advice: take a Bayer Back & Body before you start every morning and one after you finish.

Just my experience.

Good Luck, we'll be waiting for the pictures.

[67avion]

I think it was page 198 on the Avion thread. Scroll down.

[silversand]

...here's a crazy idea: ferget the aluminum exterior, and clad a new build with adhesived TPO (just tarp the "old girl" outside as you strip out the good stuff, while you build in the barn near-by)....eventually, as time/money allows, aluminize the exterior (spray spar varnish on all wood surfaces and end-cuts before TPOing)...this is pretty out of the box, but I've always had ths idea kicking around.

Just be aware that the post 2011 TPO product (the patent ran out in ~~2011) are extremely diverse (in quality); so investigate the myriad brands carefully.

[JoeChiOhki]

silversand wrote:
Matt: you may want to consider building a giant C-clamp (to lock n the vertical tub walls before the floor is removed), with foot wall (under the camper's wings)...

...however, I really like that idea of a steel box tube frame under your existing floor (sub-frame)...the altitude addition doesn't seem bad (weight?). Just add a steel cage to capture your rear and low hung tank (or, remove that tank before you start in anticipation of a newer slim tank). Once the steel sub-frame is in place, you can lose an inch to the interior, by building UP a slim basement, or a step-up floor to accommodate the new tank & heating blanket (?)

Standing up, I barely clear the lights on the ceiling with my shoes off as she currently stands. Making it any shorter and I won't be able to use her comfortably.

The thought about notching some 2x12s to fit around the tub before prying the floor off does sound like a good idea though.

The tank needs to be replaced, it's brittle and is already cracked around where the drain line fits in. I believe it's made out of polypropelyne, like the fresh tank, but has been exposed to the elements outside the camper for 40 years now.

The current tank is only held to the rig by four J brackets that are screwed into the underside of the floor.

I want to completely redo the bathroom as well, with a properly placed toilet flange instead of the bull******that was originally in there.

The shower pan is cracked, and needs replacing, I'm thinking about having a stainless steel tub made if I can get it for a decent price, otherwise, I will likely kit bash a common product to make a new floor pan out of, or custom make a new fiberglass one myself.

In order to do this, I need to rebuild the floor under the shower, to relocate the plumbing for it. Again, this is one of those times where I'd love to simply start from scratch, but I'm limited on space to work, so I'm basically having to do a gut/rebuild to fix the flaws in the design of this 40 year old girl.

[silversand]

Matt: you may want to consider building a giant C-clamp (to lock n the vertical tub walls before the floor is removed), with foot wall (under the camper's wings)...

...however, I really like that idea of a steel box tube frame under your existing floor (sub-frame)...the altitude addition doesn't seem bad (weight?). Just add a steel cage to capture your rear and low hung tank (or, remove that tank before you start in anticipation of a newer slim tank). Once the steel sub-frame is in place, you can lose an inch to the interior, by building UP a slim basement, or a step-up floor to accommodate the new tank & heating blanket (?) There are RV holdng tanks as slim as 5 inches H (22 gallons) available.

[JoeChiOhki]

MikeJinCO wrote:
Being a mechanical engineer with a little structural experience, when one of the main rail beams(two 2x2's with some 1/8"/3mm plywood on each side) broke on mine I just did the calcs and ended up building a subframe with two 1-1/2" sq 16 ga steel tubes(side by side not top and bottom) under each side all welded up. I used some cross pieces and had to build around the drain pipe. When complete and painted with POR-15, I filled the large holes with sheet foam, then put a rubber pad on top. It is light enough for two small people to easily pick up to put in the truck and strong enough to support a very heavy camper with a long overhang.

If rebuilding I would use a TJI/BCI floor/roof joist which comes in 7-1/2", 9.5", 11-7/8" and 14" depths. Properties are strong, straight,won't warp and not much more expensive than structural lumber. Almost any real lumber yard has them, but not HD or Lowes.

I'd be happy to help.

Mike, not certain a Chipboard based wood I-beam would do me much good given that this is a 40 year old camper. They didn't have basements back when this model was built (Some of their later 70s models, early 80s did, but they were an entirely different design from the early 70s late 60's units).

My current floor is maybe 3" thick, trussing it from the outside is not feasible, as the holding tank is in the way.

What I'd like to do is use 2x3s or 2x4s for the new floor with plywood on both sides (if I go wood), with an new subfloor area in the rear built to house the newer holding tank and plumbing so that it's no longer hanging out in the air (Would allow for the addition of a heating pad for the tank so that I could keep it from freezing up during winter camping).

67avion wrote:
Well, that's a bit different alright. Take a look at the work being done by D1trout on the Avion rebuild string. He dropped the floor, but first he put in supports.You can see the whole explanation, with photos, on page 198. I understand your situation is different...but its worth taking a look.

Do you happen to have the page numbers for his part on that thread? It's gotten so huge, it's hard to find a specific person's work anymore.

[MikeJinCO]

Being a mechanical engineer with a little structural experience, when one of the main rail beams(two 2x2's with some 1/8"/3mm plywood on each side) broke on mine I just did the calcs and ended up building a subframe with two 1-1/2" sq 16 ga steel tubes(side by side not top and bottom) under each side all welded up. I used some cross pieces and had to build around the drain pipe. When complete and painted with POR-15, I filled the large holes with sheet foam, then put a rubber pad on top. It is light enough for two small people to easily pick up to put in the truck and strong enough to support a very heavy camper with a long overhang.

If rebuilding I would use a TJI/BCI floor/roof joist which comes in 7-1/2", 9.5", 11-7/8" and 14" depths. Properties are strong, straight,won't warp and not much more expensive than structural lumber. Almost any real lumber yard has them, but not HD or Lowes.

I'd be happy to help.

[67avion]

Well, that's a bit different alright. Take a look at the work being done by D1trout on the Avion rebuild string. He dropped the floor, but first he put in supports.You can see the whole explanation, with photos, on page 198. I understand your situation is different...but its worth taking a look.

[JoeChiOhki]

The tub of the camper is simply plywood standing on end, the floor screwed in from the perimeter.

The floor isn't rotten, just badly designed by KIT. It's a 1/2" sheet of plywood outer bottom with 1x2s on top making up an 1 1/2" structure with a ~3/4" particle board layer on the top. Particle board doesn't provide much strength to a truss and subsequently, anything past the end of the main 8' section of floor sags when it's used to hold the camper's weight.

When you lift the camper up, the floor straightens back out. Structurally, the floor should be supporting the over hang in addition to the 12' 1x3s that run the length of the camper in the walls.

I'd love to simply build a whole new frame built on a 2x2 size base instead of the 1x frame that the camper was originally built with, but my barn stall is only big enough to fit one camper in, plus getting new aluminum for the nose, roof, front and rear would be insanely expensive with today's metal prices (Camper would end up being wider because of the thicker framing members).

Inside, the only things anchored to the floor are the two cabinets in the dinette, the holding tank that hangs from it on the underside. All of the plumbing rides up on the wings except for the drain in the shower and the line going through the floor to the tank for the toilet (Single holding tank).

My main concern is the camper simply spreading wide once the floor is pulled, I know she'll mostly hold together given how much flexing the tub does right now because the floor isn't really doing anything to give it rigidity anymore.

The front and rear walls are a truss made with a plywood sandwich which gives them far more rigidity than the side walls, which is simply 1/8" thick paneling over a 1x2, 1x3 frame.

I originally thought about sistering the floor, but the placement of the holding tank, which I'm plotting to replace with a newer ABS RV tank and the alignment of the grey water plumbing under the over hanging floor makes it a no go.

If I pulled the 2x3s that run under the edge of the wings, I could probably drop the whole camper tub as one piece, its simply screwed in to the bottom of the 1x3's that run along the bottom edge of the wing walls.

[MikeJinCO]

Being a mechanical engineer with a little structural experience, when one of the main rail beams(two 2x2's with some 1/8"/3mm plywood on each side)and much broke on mine I just did the calcs and ended up with two 1-1/2" sq 16 ga steel tubes(side by side not top and bottom) under each side all welded up. I used some cross pieces and then filled the large holes with sheet foam, the put a rubber pad on top. The mistake I made was in trying to repair the rail beam first, I should have let it sit on my steel frame off the truck for a month or two to get resettled, then repair the beams. With only a two month trip this winter to Mexico it did real well.

If rebuilding I would use a TJI/BCI floor joist which comes in 7-1/2", 9.5", 11-7/8" and 14" depths. Properties are strong, straight, and not much more expensive than structural lumber. Almost any real lumber yard has them, not HD or Lowes.

I'd be happy to help.

[67avion]

Whew. Silver does Class A rebuiilds. I suspect that you are interested in redneck engineering.

Check first to make sure that the floor in the overhang is an integral part of the larger tub. In the Avion it is not. It is attached to the frame and the 8 foot section of floor, but that is the reason that it frequently fails.

So the fix is relatively straightforward. (1) Drop the camper onto blocks to support the floor. (2) Find a way to support the upper part of the affected area - and there's lots of ideas of how to do that depending on the configuration. (3) Tear out the rotten section. (4) Replace section.

You are getting into plumbing and holding tanks and toilets. But they come out and go in like anything else.

Can be done on a budget. Best of luck.

[silversand]

....in the factory visits I've done watching the truck camper construction process, all of them build from the tub up (the tub is built, then the under-wings; all cabinets are added just after walls are connected)...hmmm?

...in my mind, a full foot wall framing (or 2x6 x) would probably need to be built just under the wings and as far rear as possible on both sides, and stabilized against collapse; then the camper lowered onto this foot wall.

You need to work up a real 3D CAD model, with the structure, and do fea runs. The problem is: you don't know where the weak parts of the structure are "hidden", let alone what the structure actually is under "the skin" ! Even worse, the camper floor has to be removed.....by someone working under the camper (extremely dangerous). And, the entire guts of the camper (all furniture, fixtures) have to be removed from the inside 1st (they are all attached to the floor on the inside).

Why even pull the floor:

You really need a structural engineer to have a look, and possibly suggest "sistering" some kind of full camper-length beams UNDER the existing floor, then lowering camper onto the beams (the camper weight straightening out the floor), then with some manner of understructure, connecting the new sister beams to the camper with large lag bolts.

Just build another shell:

What about building a new camper from scratch (and gut all the current appliances and jacks and electrical, and install in your newly-built unit?)...the appliances, electricals, cabinetry, shower parts, toilet, kitchen accouterments and windows and door and roof-top vents are the most expensive components. The shell can be built relatively inexpensively (you could probably frame up the new camper in 2 weeks; then rent a sprayer, and coat the entire plywood structure in water-based quick dry spar varnish several times in 1 day, then attach aluminum cladding from your old camper, and buy what you need to finish the skinning)....?

....just thinking allowed...

I remember reading about a Frank Lloyd Wright house (Falling Water) balcony system sagging down into the river below; the fix was to introduce tensioner cables, then tension them to lift the sagged balcony...