03-14-2012, 07:58 AM
Hi Bruce,
Welcome
to the forum.
What sort of support will the plywood be getting? Dimensional lumber (e.g. 1x4) tend to be less stable than plywood in terms of movement under heat/cold or humid/dry conditions. You might consider going to an open frame (which you will have under the ply anyway) and 2" foam without the plywood. It's a lot lighter, and the foam is completely impervious to temperature or humidity changes. Supported by a frame not more that 24" on centre, it should be plenty strong enough (as long as you do not need to walk on it
). Painting the frame with a couple coats of paint will help prevent dimensional changes due to humiidity.
Hope that helps.
Andrew
Welcome
to the forum.What sort of support will the plywood be getting? Dimensional lumber (e.g. 1x4) tend to be less stable than plywood in terms of movement under heat/cold or humid/dry conditions. You might consider going to an open frame (which you will have under the ply anyway) and 2" foam without the plywood. It's a lot lighter, and the foam is completely impervious to temperature or humidity changes. Supported by a frame not more that 24" on centre, it should be plenty strong enough (as long as you do not need to walk on it
). Painting the frame with a couple coats of paint will help prevent dimensional changes due to humiidity.Hope that helps.
Andrew