Sub-floor dilemma

[CraigCam]

Need help, not sure what the right thing to do is. I have gutted my 1970 overlander. In looking at the subfloor, most has been replaced sometime it's life. My quandry is they cut out the original around the base of the skins and did not remove the section under the C channel. When I pull the subfloor up should I remove it from under the C channel. My job is much easier if I don't and just put it back in like it is?

[CraigCam]

Also, I'm looking for airstream remodeling expert or shop in the Lakeland / Polk County Fl area? Or, even better would be an air forum member who is local and could give me some much needed advise as I progress on.

[cwf]

Ideally, yes, the wood between the Trailer steel frame and the C channel should continue across to the other side of the trailer and under that C channel. There are several reasons... discussed all over the forum. Search "frame off" ...

If you are that far in, it is decision time.

[cwf]

Oh, there is a link on the main forum page where you can search for folks in your area

[AldeanFan]

To fix it right you need to replace the wood between the frame and c channel.
Since
That wood is the edge of the floor and the most likely to get wet, it is the first part to rot.
Once the wood between the frame and shell rots you loose the solid connection.

You don't need to do a shell off, but you do need to replace that wood.

[Lumatic]

Aistreams use a semi-monocoque design. this means the attachment of the coach walls to the subfloor at the C channel plays a major role to the structural integrity of the Airstream.

[Isuzusweet]

Replace subfoor to include the C channel is a must. A pain in the butt, maybe, but not that much more difficult than replacing what you have.

A shell off is not necessary if the frame is in good shape. I would get all the old sub floor out, including the C channel in stages as you replace the flooring. Then replace the two curved end pieces first with a full length piece that would end on a frame piece. I would half lap the end joint on the frame rail so that other subfloor pices lock into other pieces. Then I would cut pieces along the sides with again half lap joints over framework. With the final middle pieces to finish off.

https://www.amazon.com/CMT-835-502-1.../dp/B000P4LPJ6

Set up your router and router a bit of your subfloor material, then cut piece in two and place rabbit over rabbit; adjusting router depth until both pieces fit flush to each other. Now you have created a half lap joint.

Subfloor material of choice is Coosa board as it will not rot, grow mild, mildew or decay. Expensive, yes but you won't have to ever do this job again. I used 3/4" Coosa as 5/8" wasn't available up here and machined the edges down to 5/8" to fit channel.

Cheers
Tony