Floor design

[WesGrimes]

I am planning to create a floor out of 3/4" exterior grade bc fir plywood attached to the steel frame.

The spaces between the members is approx 60" x 40".


I am a little nervous about having such a large unsupported area in between frame members.

Any thoughts on if this will be an issue? I do not want to wake up to falling through the floor.

[bobhenry]

It will never happen. 3/4 flooring is used in homes 16" or 24" o/c with people jumping rope next to the piano. Your floor will largely be covered with some type of bedding. Try stuffing an innerspring mattress thru a 2 foot hole is will not happen. You are worrying for no reason. If you need a little reassuring block the frame and toss on the 3/4 and both of ya get on there and jump it is more than enough. Just start making sawdust.

[Dirran]

My chassis is almost identical to yours and I used 15mm or 3/8" ply for the floor to minimise weight.
To overcome the expanse of unsupported floor, I built a storage area under the cabin floor and under the galley floor. The cabin storage has a 2 piece lid whereas the galley storage area which is 8" deep is open, giving me a huge amount of storage below the galley.
These storage areas or 'boots' as I call them strengthen the floor area and provide loads of extra storage.
I will post some photos today just in case it is helpful.
By the way, I weigh in at about 240 lbs and can stand in the centre of the floor of each boot, or any part of the floor, and there is no flexing or movement on any part of the floor.
Errol.

[Dirran]

Sorry, but I didn't really answer your question did I?
I agree with bobhenry. There is no way you will flex that stuff.

[WesGrimes]

Thanks for the feedback guys!

[Lou Park]

Unless you're a jenny craig dropout, you're not going anywhere. Just through a few extra self tapping screws into the frame and you should be fine. However you may want to watch for a little sagging.
Lou

[eamarquardt]

If you are still concerned, just glue and screw some 2X2s in a fore and aft direction to the underside of the plywood inbetween your cross members. Then should you put on a ton of weight, you be covered (or supported).

Cheers,

Gus

[WesGrimes]

Well at 6'2" 240lbs, I would say that I could be classified as a Jenny Craig drop out already. The 2x2 spars sound like a good idea, but they conflict a bit with my plan to layer the bottom of the 3/4" with steel flashing for water proofing.

[danlott]

Lots of beds in peoples homes are only supported by 1/2" plywood or sometimes even less. 3/4" plywood is more than you need.

Dan