foundation

[dknelson]

I am not entirely sure what you mean by "foundation." Indeed I am not even sure what you mean by 20' x 16'!! But let me give some thoughts anyway. If we are talking L-girder construction I think the standard was 1x2s to make the Ls. If we are talking table top then the wood I favor is 1x4 pine, although more and more people are having plywood ripped at the lumber yard to equal dimensional lumber -- the reason being is that today's dimensional lumber tends to be farm raised pine that is not always the straightest or sturdy enough (I have driven drywall screws entirely through a piece of pine!)
Some might use 1x3 furring stips but they tends to be even lesser quality wood.
As to table tops, I am using 1/2 plywood "handi-panels" that come in precut 2'x4' size -- but (and this is a big but) it is very well braced and framed and for larger areas most people prefer 5/8" plywood for its greater stability
Give me more details and maybe I can be more help!
Dave Nelson

[Anonymous]

What is the best type of wood to use for a foundation on a layout of app. 20' by 16'. Thanks