Newbie needs advice on fixing rotten floor

[Lyvettely]

Hi all,
I bought my 1968 ambassador a week ago. It has dry rot at both ends of the airstream as well as the floor under a window. The middle floor seems intact. I have been reading some of the threads on floor replacement and it really seems intense! So intense that I am left confused. Here are my questions.

What is the underbelly pan?
What is the banana wrap?
Why do you have to remove the banana wrap in order to replace (or slide in) the bathroom floor?

What kind of advice would you give to someone like me with little (but growing) knowledge of airstreams to replace the dry rot on the floor.

I guess it would help to mention what my plans for this airsream would be. I will not be traveling with the airstream for a good long time. I am using this airstream as another living space or "apartment" which will be parked on our property.

My plan was to cut out the sections that are rotten and replace them with new plywood. But it seems that because the dry rot is where it is, this job is easier said than done.

[averagejoe]

Originally Posted by Lyvettely

Hi all,...
What is the underbelly pan?
What is the banana wrap?
Why do you have to remove the banana wrap in order to replace (or slide in) the bathroom floor?
...

--The belly pan is the sheet of aluminum that encloses the bottom.
--The banana wrap(s) are the curved pieces that go from the bottom rub rail to the belly pan. I'm not certain, but I think of them as being the compound pieces at each corner. The simple curved pieces along the sides are just "skin."
--Why remove? Well, when you remove the rub rail you will see that that the banana skin comes up to meet the shell at the C channel and overlaps the upper skins at that point. Maybe it would be better to say that the shell is attached to the C channel and sits on top of the plywood floor. The banana wraps come up past the floor to attach and overlap the shell. So it's the banana wrap that conceals the floor. If you're going to slide new floor in, the banana wrap has to come down. It's actually not that big a deal. Drill out 20 or so pop rivets that hold the rub rail on and the then the ones that attach the banana wrap to the shell then the few that attach the banana wrap to the belly pan (actually, take the belly pan ones out first) and viola, you are looking at the edge of the floor.

Some members do cut out sections of the floor and replace them without going under the C channel. Nothing wrong with that if you've got a localized weak spot. However, most rot is along the wall and is either so close to it or under it that you can't put in a doubler underneath, so you're forced to take out the floor under the C channel--that may be a small section, not the whole 4' panel.

If you ever plan to tow your Airstream, you should do the floor right while it's accessible. I would think that also goes if it's a full-time apartment. On the other hand, if you're just using it as a once in a while guest room, you might see if laying down a pergo-type floor gives you enough stiffness. This would really be a last-ditch solution, since there's usually rot around the door and you need to have a sound floor in such a high traffic location.

You can get an idea of what it takes to slide the floor out in posts #7 and 8 in this thread
http://www.airforums.com/forums/f421...ion-37609.html
where the C channel bolts are visible. You also need to remove (usually by cutting, due to rust) the "elevator" bolts that hold the floor to the frame (which means the belly pan has to come down).

The good side of this is that you'll discover the rusty frame and in no time you'll have your wire brush out and soon you'll be POR-15'ing the frame and feel really good about it!

joe

[Lyvettely]

Thank You!

[malconium]

If the amount of floor that you have to replace is not extensive you can do it all without removing the belly pan or taking off the rub rail. To remove the old flooring you can use a circular saw with the blade depth set to just shy of the plywood thickness. If the part of the floor that you need to cut out crosses over any of the frame memebers (you should be able to see the heads of the bolts or screws) you can saw off all the plywood near the bolts and cut them off from above after most of the wood is out of the way. Some people have used a hole saw to cut the plywood around the bolts to get it off. Then the bolts are accessible from above too. If the rot extends under the edge of the body you typically will have to remove the bottom part of the inner skin in that area so that you can rebolt the floor in place. You can cut the plywood out by using a cut off wheel from the side to cut the bolts after you have sawn out most of the plywood. Use self-drilling self-taping screws to reattach the plywood from above without having to have access from under the floor.

Feel free to to ask for more detail if what I am saying above does not make enough sense.

Malcolm

[hjan]

I just purchased a 75 argosy MH and am wondering if it also has the same type hold down bolts and c channel construction. Right inside the door is a rotten spot along the wall and I'm sure it continues on the other side of the bulkhead (thin mahogany wall ) and underneath where the fridge should go. (someone boarded up the fridge vents, covered over the fridge floor with particle board and put in a tiny electric fridge that might hold a head of lettuce and a bottle of water but little else. Its gotta go) The RV store says to remove the cabinets and shelving held together with a bazillion rivits and bring it in. It will cost over $1700 to replace 1/4 of the floor if I don't.
Which way is easier?

[malconium]

Hi Hjan,

I don't know if the floor of a Motor Home are constructed in the same was as for a trailer or not. I would suggest you post a thread in the MH section asking about the floor construction.

Malcolm

[gYpsydreamin]

Originally Posted by malconium

If the amount of floor that you have to replace is not extensive you can do it all without removing the belly pan or taking off the rub rail. To remove the old flooring you can use a circular saw with the blade depth set to just shy of the plywood thickness. If the part of the floor that you need to cut out crosses over any of the frame memebers (you should be able to see the heads of the bolts or screws) you can saw off all the plywood near the bolts and cut them off from above after most of the wood is out of the way. Some people have used a hole saw to cut the plywood around the bolts to get it off. Then the bolts are accessible from above too. If the rot extends under the edge of the body you typically will have to remove the bottom part of the inner skin in that area so that you can rebolt the floor in place. You can cut the plywood out by using a cut off wheel from the side to cut the bolts after you have sawn out most of the plywood. Use self-drilling self-taping screws to reattach the plywood from above without having to have access from under the floor.

Feel free to to ask for more detail if what I am saying above does not make enough sense.

Malcolm

I know I'm a little late to this party but Malconium you seem to have an idea of what you're talking about here so I hope you can help me! I know I'll have to replace some of the floor in the rear of my sovereign but I can't seem to figure out exactly where to cut the old plywood, the rot is against the back wall so should I cut all the way to where the last bolts are? (about 3' from the rot if I remember correctly) let me see if I can add a picture here...

[gYpsydreamin]

[johnamjr]

We have just removed the plywood in our rear bath. But now the shell is too close to the frame install the new plywood. Any suggestions on how to work that out?

Thanks.


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[TennTex]

My run at this is described here: http://www.airforums.com/forums/f4/s...-a-119687.html The floor replacement issue particularly in posts #9-19.

Have fun,
Alan

[malconium]

In general if you need to remove some rotted plywood you can remove what is actually rotted and splice back in a new piece by using a plywood spline under the joint between the new and old plywood. Use glue and screws to attach the spline to both the new and old pieces. I would suggest that the spline be 1/2" to 3/4" plywood around at least 3" wide.

If the body is too close to the frame I assume that means it settled down a little bit after taking out the old plywood. Find some place where you can insert a lever or jack to lift up on that part of the body so that you can get new plywood under the body edge.

[johnamjr]

The splice idea I would use if it were just a little spot. But it's from wheel well to wheel well. I have most of it cut out, pan dropped, and the tank out. I need to take out the couch and cabinet to get back to the wheel wells. The frame is in great shape very little rust. I did have to have new metal bent up for the rear under the hatch and the bar that is welded between the frame rails back there.

I'll post some pics of the progress.


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[johnamjr]

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[Rob Carey]

Johnamjr
Im new to the airstream world but I'm well into my first project, to fit a new floor to the rear of your trailer I'd advise removing the wall panels as this will expose the fixing points for the new floor. As the floor takes all the weight of the shell you will need some good fixings in the C channel.
You may also need to remove the inside of the window frame as well.
You can use the old floor as a template to make life easier, or use a cardboard template. The ply will need to be a nice positive fit, don't cut it too small as this will affect the rigidity of the trailer.
Replace the ply in 2 half's as trying to get 1 piece in would be impossible.
Slightly prise up the C channel to give you more room when sliding/ levering the new floor in.
If you are any good with a welder you can weld in a piece of angle where the 2 half's of the new ply meet to support the lap or cut an 8" strip of ply (4" lap on each side) glue AND screw to the underside of the floor.

When drilling the rivets out on the wall panels only drill the head of the rivet don't go all the way through this way you will be able to use the same holes with the same size rivets to put it back together.

[cp1977]

what a timely revival to this thread! I am in the midst of replacing a section of floor at the rear curb corner of my 77 safari (rear bath). the rot was beneath the shell and about 6" wide. it went from basically around the curved part of the corner. Started at rear bumper where the frame meets bumper and then around to the first outrigger. The wood was rotted right away between the outrigger and the shell with the shell having relaxed down against the outrigger. I tried jacking the shell up a bit to regain the spacing so I could slide in the new floor piece. No luck, the entire coach lifts when I jack. I guess it has been down so long it likes it there and the whole body has shifted to conform to it. Not sure what to do, I jacked the shell (and the accompanying coach) up about a 1/2" and left the jack in place overnight. Hoping that it will relax and perhaps I'll gain the space I need back. Any other ideas on how to get the shell raised up off the outrigger? The next outrigger is only about 15" away and the floor between it and the shell is still in good shape.
Lorry

[johnamjr]

The C channel looks to be in good shape. I took out the inner skin yesterday. I need to weld in a new steel C channel under the rear. and new mounts for the black tank. A brace down the middle sounds like a good idea. I am not sure how backing the floor with wood would effect how the black tank fits. I am also going to take the new floor back to the wheel wells. I found more rot once I dropped the pan.

[johnamjr]

Lorry

Do u have the pan dropped?

I am going to have the same issue. My outer skin is now touching the rear frame rails. I am planning on jacking up both sides of the shell. To try and get the new floor under it.


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[cp1977]

I haven't dropped the pan yet, I was hoping to confine my repairs to this corner but I am having second thoughts. I have a good workspace available this winter and lots of time so I am considering removing the bathroom (rear), drop pans and make sure the whole back end is in good shape. The frame itself is in very good shape, at least the curb side is. I was hesitating because it seems that to pull the bathroom, I pretty much need to pull the whole interior. Everything inside an airstream seems to be connected. One factor in favour of pulling bath and pans is that my waste valves are leaking and it would appear to be almost impossible to service or replace them with the pans and rear skins in place.
Further to the shell on the outriggers, at the rear, where frame at bumper meets shell, the shell has not relaxed, there was enough wood hanging on there to hold it in place.
I guess I have a decision to make...
Lorry

[BoldAdventure]

I don't have technical advice, but some personal experience on how you might be feeling.

Take breaks, and don't panic! I'm a newbie too, and we discovered rotten floor. It's very easy to stare at this and get panicked and worried you are in over your head and this is going to turn into a nightmare. Take a break, relax, don't stress. I over worried at first when uncovering the floor.

It's not easy as cake, but if you take your time, it's certainly doable and a lot easier than the mountain I made in my head.

Good luck in your endeavor.

[SuperTrouper]

I have nearly the same vintage as BoldAdventure (2008 27FB). I got away with drying the wood and treating it but the whole operation took a few weeks and dropping the belly pan is recommended. My whole sad story start on post 245 in this thread: http://www.airforums.com/forums/f396...ml#post1262866


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