Floor Span - How much is too much?

[GeoDrop]

Working on the design of my trailer... which will be ~6'x10'. My question is what is an acceptable amount between floor supports? I'm doing my best to keep things lite and cheap. :-) I am intending to do a sandwich floor construction.

Is a 4'-5' span between cross members to much? Would I have sag? What if I had a space of 4' x5'? with no supports underneath, is that stretching it too far?

Thanks,

[aggie79]

My teardrop floor is sandwich construction and has "no crossmember" area of approximately 5' wide x 6 1/2' long. Without a mattress, there is no flex with 340# load (mostly me but including my wife).

If you have the clearance at your axle - a torsion axle has a camber that may encroach into the frame area - a lengthwise crossmember may weigh less than 2 or more transverse crossmembers.

[GeoDrop]

That makes me feel better than.. what is your floor sandwich consist of?

My teardrop floor is sandwich construction and has "no crossmember" area of approximately 5' wide x 6 1/2' long. Without a mattress, there is no flex with 340# load (mostly me but including my wife).

If you have the clearance at your axle - a torsion axle has a camber that may encroach into the frame area - a lengthwise crossmember may weigh less than 2 or more transverse crossmembers.

[aggie79]

I used 1/4" plywood (actually slightly thinner 6mm Russian Birch), 3/4" framing (1x2s laid flat @ 16" o.c.) with insulation in the voids, and 1/4" plywood. Here's a picture of it (ignore the 3/4" mdf straight edge I used to make the bevel cut with my circular saw.)