How Far Will 1/2" Plywood Span?

[bdosborn]

I'm working through the framing for a standy floor I'm designing and I don't know how far I can span with 1/2" plywood. I would think that I could go 24" but I'm not sure. Anybody have any input?
Thanks,
Bruce

[Podunkfla]

I'm working through the framing for a standy floor I'm designing and I don't know how far I can span with 1/2" plywood. I would think that I could go 24" but I'm not sure. Anybody have any input?
Thanks,
Bruce

I guess a lot would depend on the quality of the plywood? Nine to eleven ply 1/2" cabinet grade ply is a lot stronger (and flatter) than say, CDX roof sheathing or common A/C plywood from the big box stores. Considering a couple more 2 x 2's wouldn't add any significant weight, I'd prolly go 16" OC or thereabouts?

[bobhenry]

Span stamp is on the plywood, the 2 numbers are roof span 1st and subfloor span 2nd. This stamp shows 1/2 at 32 / 16 so for floor max of 16"
this will appear a bit spongey if you are a big fellow.

[bdosborn]

Cool! I didn't know that. Now I wonder how far a 2x2 will span. I hope its 54" because that's how wide my trailer is.

Thanks,
Bruce (who seems to becoming a bigger fellow every year)

[mikeschn]

That sounds about right... the dropped floor in the ET was real saggy until I braced it up in the center. Now it's not too bad. I guess my span is about 27" across the trailer, and slightly less fore to aft. That's 1/2" furniture grade birch (not baltic).

Mike...