Newbie needs advice on fixing rotten floor

[TennTex]

The approach to replacing the rear section of subfloor has been described in different ways on the forums. Concerned about the structural role the floor plays in the monocoque design, I chose to use a single piece of ply, sliding it in from the rear. Getting enough space required trimming a slight bit of exterior skin on the street side, which didn't matter as I was attaching a flashing piece under the skin to water-proof the back anyway. It also required using 2x4's in the frame channels pushed downward, along with a 4x4 lever in the back hatch opening pushed upward, to increase the gap just enough to slide in the plywood sheet (with a little "persuasion" ). Described in the link I posted earlier.

Two pieces with a backing reinforcement will not work with the black tank in the rear. Some have made the pieced parts join on a beefed-up main frame channel, widened by welding angle to it (one version shown by mccrosti in the link above). Others have used a broad half-lapped joint to avoid the backing piece.

Looking forward to seeing how your approach goes; just remember to have fun...

Alan

[cp1977]

thanks all
Alan, I think I understand what you did, I expect it will become more obvious when I get more skins off and the bottom pan off. I will look at it all tomorrow and decide if I want to tackle this considering it means I have to pull the whole back interior out... but I am definitely leaning towards doing it properly so I don't end up having to do it again. I don't imagine doing it correctly would hurt the resale either, I'll tear a page from all the other AS folks and make sure I take lots of pictures as I go.
Lorry

[cp1977]

Pulled off the rear street side banana today and had a peek inside. There is some floor rot in there but not nearly as extensive as on curb side. mostly it appears at very back near where the frame rail would be. outrigger looks relatively good, some surface rust but nothing serious. There is a soft spot by the first outrigger, I have to take the bottom skin off tomorrow and have a closer look at the outriggers behind the wheel well. I don't expect much problem, the rot was much worse curb side and the outriggers were still solid. The rot appears to be mostly the direct result of the weak design of the rear bumper to coach connection. I'm not sure what I can do to fix that. I am going to remove the bottom pan under the tanks tomorrow and have a look at the floor from beneath, I don't expect to see much wood right against the body. If necessary I will remove the bathroom fixtures and interior walls so I can get at the c channel and get a new floor installed without pulling the shell.
Lorry

[cp1977]

Johnamgr - I left the jack in place lifting the shell (actually the whole coach) about 3/4" on Saturday and today I let the jack down. There was no noticeable difference in the gap between shell c channel and the outrigger, still not enough to get floor in. The shell had not lifted away from the outrigger. Not sure how I'm going to get just the shell lifted off the outrigger. I'm still a long ways from putting the floor back in, something will come up.
Lorry

[johnamjr]

Lorry I have read about just having to shoehorn it in there. But like you I wish we could just slide it back in. I hope to try this weekend to get the subfloor back in.

As far as splicing. Anyone see cons to using a 3" wide by ⅛" thick. Plate steal.

The space I would need to spice would be where the black water tank gets installed under the floor. So space is tight.

Here is a pic after I welded new black tank supports on the frame and a new steal c channel between the rear frame rails.




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[johnamjr]

It's the black bar under the shell. Mine was completely gone.


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[TennTex]

[QUOTE]

Originally Posted by johnamjr

Lorry I have read about just having to shoehorn it in there. But like you I wish we could just slide it back in. I hope to try this weekend to get the subfloor back in.

Is there no play in the frame when pushing down or standing on the ends of the frame rails? (My method shown below, 200 lb son optional.) Also, if the shell rests that firmly on the frame, it makes me wonder if one or more of the outriggers forward have broken, with settling of the shell. Other signs of this might be bulkhead separation from inner skins, broken wheel wells, etc. Only direct inspection of the outrigger/rail joints can show this with certainty.

As far as splicing. Anyone see cons to using a 3" wide by ⅛" thick. Plate steal.

Fasteners will be a problem. You don't want the black tank top rubbing against bolt ends. You also will need to fit and seal the tank's galvanized box edge around the splice, which is no big deal. If splicing, widening the frame rail and bolting to it as referred to previously seems a better route to me.

[cp1977]

TT - ahh, now I see. I'll try the 2.4 method, it may give me enough room at the rear frame/coach interface. Still not sure how I'll get the shell away from the first outrigger though, the outrigger itself and the next 2 (curbside) are all in good shape, a bit of surface rust but otherwise sound. And, the floor is fine over those next two outriggers.. the shell just seems to have relaxed around the curve as there is still the required space (1/2" in my case) for the floor where the shell meets the frame rails.
Floor seems a bit odd though, other posters on the forums indicate that this generation safaris had 5/8" or thicker flooring, I have measured mine in several places and it is nominal 1/2" ie closer to 15/32 or 7/16".

[Aerowood]

You can also jack the frame and shell apart from the inside by by spanning a couple of the shell ribs at the top with a 2X4 and then put another piece on a jack that is placed over a frame cross member. I replaced my complete floor, shell on, without splicing the floor boards. several pictures in my thread below.

[cp1977]

Almost ready to start trying to put in the new floor pieces. I got the grey and black tanks out yesterday with a bit of effort and a lot of head scratching. Now I just need to peel off the inside skins. I don't think I'll remove them completely, just going to cut out the bottom 12". It will all be contained in the closet and behind the new vanity so pulling entire skins in back isn't necessary. I think I'll switch my plumbing over to pex while everything is open. I can also add a bypass to my hotwater heater. Makes you wonder why Airstream wouldn't put in bypass, 3 valves and 3" of pipe would make winterizing a whole lot easier.
This might be a first, when pulling my grey tank, I noticed there was still about 2 or 3 gallons of water in it. VERY stinky water. Grey water doesn't usually smell that nice but it really shouldn't make you gag. I removed tank very carefully to be sure I didn't spill any on the shop floor and dragged it outside and away from the shop. I dumped it out on the grass and the stink became obvious. There was a dead weasel on the ground. How he got in the tank and how long he had been there is a mystery. I had noticed a bit of a bad odor from the shower pan when I was winterizing about a month or so ago so he was probably in there then. A lucky thing the tanks were coming out, that would have been a nasty surprise next summer.
Lorry

[johnamjr]

Need advise on jacking up the shell a bit or supporting it to remove more of the sub floor. I have checked the frame supports and their all good.


I was thinking up trying to support it from the inside with wood running length ways and cribbing to spread the load.

Any advise?


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[johnamjr]

Aerowood can you post your pictures or a link I think I am trying the same thing.


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[Aerowood]

I don't think I took any pictures of that process, but I think there might be a picture in the link below showing how I supported the rear of the shell after the structural components of the shell to the frame interface were all removed. I spent a lot of time reworking the rear area.