1971 Airstream Sovereign Subfloor

[emilyweav]

I just purchased a Sovereign this weekend! I'm so excited but I am wondering what to do about replacing the subfloor. There are at least two spots that need to be replaced and I would like to see the condition of the frame while doing this project, but from the first panel pulled at the front it looks like the plywood sits under the C channel. What is the best way to do this type of repair work with the shell on? Thanks!

[dbj216]

Hello from Colorado: Welcome to the vintage Airstream hobby.

Our seventies Airstreams are prone to subfloor rot, rear end separation, rusty frames, and cracked and buckled frames, especially the longer trailers. Other than that, they are pretty good trailers. All of this can be repaired.

I have a 75 Overlander. It had a classic case of rear end separation due to the rear subfloor rotting away, due to a poor seal between body and frame. I repaired this problem this winter. My rear end ain't separated any more. I also patched two places where the subfloor rotted through.

Then there is the "while I'm at it" project list. My black tank was broken, my gray tank woefully small (and your trailer doesn't have a gray tank I believe), my water heater and fridge were shot, and on and on.

It is possible to replace a large section of subfloor with the body on the trailer. I've not done it, but I've seen threads on the subject. I read about one fellow who loosened the body from the frame and elevated it ever so gently to clear the thickness of the subfloor and push it in from the outside. But my trailer has the upside down "F" under the "C" floor channel where the plywood edges are in the F.

You really should drop the belly pan to inspect the frame, clean out dead varmints, replace icky insulation, and see what the subfloor needs.

Take a look at the attached project thread on my 75 Overlander to see what I've been up to. It ain't pretty.

David

[ke6gkv]

hello emilyweave, if the rot is not to bad, you can replace pieces without taking the shell off. on my 80 caravelle i had o small[8''by8'']piece by the dorr , a much bigger piece at the rear . take all screws out off the c channel, cut out rotted pieces and clesn out the c channel. you may hve to cut aroud the main bolts[2 of them]. use cut out pieces as paterns. notch out new pieces for the bolts and add new wood screws. a little"persausion'' may be needed the get the new pieces to seat in the c channel. it's not rea[ly that bad to do. ggod luck. kurt

[aawiesinger]

Hi! I just saw that you had experience with subfloor issues and I ran into this today. I am trying to put a bed in the back of my 1978 Sovereign without taking the shell off and replacing the subfloor but when I stepped on pet of it today it dropped a few inches.

Do you have any recommendations on how to reinforce it to put a bed in?

Thanks so much,
Annika

Originally Posted by dbj216

Hello from Colorado: Welcome to the vintage Airstream hobby.

Our seventies Airstreams are prone to subfloor rot, rear end separation, rusty frames, and cracked and buckled frames, especially the longer trailers. Other than that, they are pretty good trailers. All of this can be repaired.

I have a 75 Overlander. It had a classic case of rear end separation due to the rear subfloor rotting away, due to a poor seal between body and frame. I repaired this problem this winter. My rear end ain't separated any more. I also patched two places where the subfloor rotted through.

Then there is the "while I'm at it" project list. My black tank was broken, my gray tank woefully small (and your trailer doesn't have a gray tank I believe), my water heater and fridge were shot, and on and on.

It is possible to replace a large section of subfloor with the body on the trailer. I've not done it, but I've seen threads on the subject. I read about one fellow who loosened the body from the frame and elevated it ever so gently to clear the thickness of the subfloor and push it in from the outside. But my trailer has the upside down "F" under the "C" floor channel where the plywood edges are in the F.

You really should drop the belly pan to inspect the frame, clean out dead varmints, replace icky insulation, and see what the subfloor needs.

Take a look at the attached project thread on my 75 Overlander to see what I've been up to. It ain't pretty.

David

[dbj216]

Oh boy. I have not heard of a subfloor moving that much. It isn't safe for a bed or people. Sounds like you will need to start a repair project.

You may have read about "rear end separation" in the 70s trailers. This is due to rain water leaks into the subfloor at the back of the trailer and subsequently the wood rots away, the frame rusts and the whole things loses strength.

It sounds like your trailer is a mid bath model. Rather rare, and rather valuable. Mid baths are prefered over the rear bath by many folks.

Okay, do the Airstream bumper bounce test. Stand on the rear bumper over the left and right frame rails and bounce up and down. Observe the joint between the body and the frame rail. If a gap opens up, you know the body is no longer attached to the frame. This means a repair is necessary.

You can also take your ice pick and probe the subfloor in the rear external compartment. Poke around and if the ice pick pushes through the wood, it is rotted.

Then you have to start from the bottom up. I recommend you jack up the trailer safely and start removing the belly pan and insulation so you can see what's going on under there. Then you can plan your project.

There are a lot of nifty ways Airstream built these 70s trailers. But many of them have this rear subfloor rot. I can be repaired, and then you're good for the next 40 years.

Here is a photo of the rear subfloor rot on my 75 Overlander. And here is a picture of the rear subfloor rot on my former 66 Trade Wind. Both are rear bath layouts.

David