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
1977 Safari restoration
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