Subfloor thickness query...

[Iansk]

Happy New Years!

Just back from a week trekking around Texas with the family in the Silver Streak and wanted to jump back in the sovereign resto...

Everything I've learned and read states that the subfloor is 5/8 or 3/4. It was 5/8 in the SS when I redid that tt but here's the thing, in this '77 sovereign 31' the subfloor is 1/2". My tape says so, my calipers say so, the piece I brought to the lumber store says so. I have an extensive background in construction, design and fabrication so I definitely know the difference between 1/2" and 5/8". Also, there is no doubt this is the original subfloor. I have started a shell on as that's what I did for the SS and it was in worse shape. I am channeling my inner SneakingUp here. I have started at the front where the issues are the worst (trailer was stored nose down for years in a wet environment).

I guess my question is has anyone run into this? I won't do a shell off, this thing doesn't need it (or my wife won't let me). Frame is great with some surface rust and only one outrigger (so far) to replace, body is fantastic (peeling clear coat and general sun damage). I'm gutting it and rebuilding to our wants and needs. At this point I plan to go back with 1/2" as I don't see how to enlarge the C channels and also plan to install a substantial cork floor throughout. Also, we are average size and weight folks. I did weld on some support bars across where the tongue attaches to the main fraim members as there was nothing but the main frame and outriggers supporting the front floor under the gaucho (anyone near Austin need a gaucho?), a very curious design choice indeed.

Anyway... Thoughts? Comments?

Thanks,
Ian

[steve46]

I did a shell off on a 1976 25' LandYacht TradeWind and the plywood subfloor was 1/2" throughout. I replaced it with 3/4" "plytanium dryply" and routed all the edges down to 1/2" so it would fit into the c channel. I also welded in additional support in the front frame area under and in front of the gaucho for more stability (the gaucho is gone, in its place will be a dinette).

[Melody Ranch]

Do it with 1/2 inch. The 3/4 inch will, I guarantee, give you some very unwelcome surprises. I have done it and know.

[cwf]

The "old" 1/2" may be to keep AS lighter...are you planning to remove 1/2" up to perimeter or leave enough to secure the 3/4"? Or will u replace it all with a lift of the base channel?

I would epoxy underside and edges for water repellent... get low viscosity epoxy and penetrate perimeter..add support for floor and frame as needed.

[Iansk]

... is to keep with the 1/2" theme. At least 85% of the floor is fine, I'll use the scab method to repair those irreparable areas. I'll spar urathane in 3 coats the edges and undersides of all replaced pieces as well as any exposed existing subfloor.

I own several routers and do not relish rabbiting the edges of all the subfloor.

Weight is always a consideration but weight distribution trumps weight by itself. Yes, I'd like to save weight, though that's not what drives my subfloor thoughts.

Thank you,
Ian