# 3/8" ply under 1/2" foamboard; is this ok?



## videobruce (Jun 15, 2011)

Using 3/8" plywood with 1/2" rigid foamboard over it on a around the wall layout in N scale (34" table depth) using cookie cutter construction, is this a problem with the flexing, expansion & contraction of the plywood in a non temperature controlled basement?
Temperature varies from 55 to 75 degrees, but humidity has varied from 45 to sometimes close to 100%, but there is a dehumidifier, so high humidity will probably be 75 to 80%.

I was concerned with overall weight of the plywood and thickness of the foamboard when it comes to work with linkage of turnouts. I also have no plans to 'dig down' below the top of the foam for scenery reasons which is why I choose 1/2" over 1".


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## shaygetz (Sep 23, 2007)

Let your lumber sit down there for a week first, then build. It will be adjusted to the humidity by then.


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## videobruce (Jun 15, 2011)

The ply was in my garage for five months, in the basement for three more.


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