86 Sovereign Subfloor

[Viking24416]

First time airstream owner here, I need to replace the subfloor of my 86 Sovereign 31. I was planning on not popping the shell and replacing the subfloor but it seems as though the shell is sitting on top of the subfloor. Am I out of luck and need to lift the shell or is there another option?

[dbj216]

Hello and welcome to these Forums. We have a 86 Limited 34'. The subfloor is OSB in ours and I bet the same in yours.

You didn't elaborate on why your subfloor needs replaced. I've patched two water damaged spots in ours. Maybe you have assessed your floor around the perimeter of the interior and finding areas of rot. Usually the rear of the trailer receives the brunt of the floor rot issues. I'd carefully patch the holes in the subfloor before I would do the whole thing unless it was needed.

Airstreams are built as a "semi-monocoque" structure. The frame is lightweight and flexible, the body is lightweight and flexible, and the subfloor is sandwiched in between the to creating a strong, lightweight structure. Damage to any one of these three components weakens the other two. An aircraft fuselage is a full monocoque structure.

It is possible to replace a subfloor a section at a time with the shell on. You are correct that the body of the trailer sits on the subfloor with bolts through both that tie it tight to the frame. All cabinets and lower interior skins would have to be removed. The belly pan, exterior banana wraps and side wraps would have to be removed. Cutting out the old floor is the easy part. Cutting a section, removing the body to frame bolts, and fighting the new subfloor section under the body and over the frame is a real bear. But it can be done. Read about it here in these Forums.

Here is a photo of a patch job I did to our trailer. The rot was at the rear of the trailer. I think it was from a leaking tail light module. I feel the strength was restored after the repair.

David

[skyguyscott]

Welcome to the forms. You will find here are a wealth of knowledge on fixing and maintaining your airstream trailer. Unfortunately you are suffering from one of the most common and consequential problems common in airstreams: subfloor rot. The good news is that there is an entire subforum on this site dedicated to subfloor repair and replacement. It would probably be a good idea to skim through that section.

You can indeed repair or replace the subfloor without having to take the shell off. However most that hhave done so or done both find that it is easier, believe it or not, to remove the shell first. However, unless you were planning on doing a full restoration of the rest of the trailer, you probably would not want to do this.

Another option is to take it to the mothership in Jackson Center, Ohio and pay them to do it, or one of the other airstream trailer specialist like P & S trailer in Helena Ohio, to name just one.

One of the choices you’ll want to decide upon is what to replace the subfloor or section of the subfloor with. I advocate going with a composite material such as Coosa board, or if you can find it, the new composite material that airstream is now using in all of its new trailers going forward. You can opt to replace it with plywood, but if you do this, you stand a very good chance of having to replace it again in another 10 years or so. Going with composite is much more expensive in material costs at first, but will last forever, so you never ever have to do this ever again.

[Viking24416]

Sorry, there is pretty extensive rot at the front and back of the trailer as well as under the fridge and around the wheel wells. I traced the leaks to the windows in the front and rear and the fridge vent. The rot around the wheel wells seems to be centralized around the bathroom vent and on the other side, the cover has a crack so I feel as though I at least know where the water is coming from. I have stripped all of the original cabinets, flooring, and divider walls as well as taken the interior skins out. I had planned on using Advantech subflooring rather than plywood. It's stronger than plywood and is bonded with a waterproof resin. This will be a resto-mod rather than an original restoration due to the cabinetry being a complete loss.

[skyguyscott]

That sounds very typical, unfortunately, but the good news is plenty of owners have been down that road.

Given the amount of damage, you may want to seriously consider doing a shell-off as that will also allow complete access to the frame, where you can inspect and repair or stop any further damage or rust there. While it is a big job (about the biggest when it comes to AS trailer restoration), it beats missing some frame damage on your restoration, and having to redo it all, or worse, having the frame fail at some point.

Again, take a look at the threads here: "shell off" or "full monty" will reveal full and thorough threads with lots of pictures and fascinating insights detailing the journeys many others have taken.

[AMN61]

Originally Posted by Viking24416

Sorry, there is pretty extensive rot at the front and back of the trailer as well as under the fridge and around the wheel wells. I traced the leaks to the windows in the front and rear and the fridge vent. The rot around the wheel wells seems to be centralized around the bathroom vent and on the other side, the cover has a crack so I feel as though I at least know where the water is coming from. I have stripped all of the original cabinets, flooring, and divider walls as well as taken the interior skins out. I had planned on using Advantech subflooring rather than plywood. It's stronger than plywood and is bonded with a waterproof resin. This will be a resto-mod rather than an original restoration due to the cabinetry being a complete loss.

How did it go with the Advantech? We are renovating a 61 Overlander

[Viking24416]

It went well, The Advantech is 3/4 instead of 5/8 so in order to use the channel around the frame I needed to route the edges of the Advantech down to the 5/8 so it would slide in. as one could imagine the hardest part was matching the radius in the corners but once that was done it went very quickly.