Would I be able to get away with using 1/4" plywood with 1" foamboard over top
for sub-roadbed[?] Or should I double up on the foamboard[?]
I appreciate all your reponses [:)]
Gordon
This should be fine, 1" foam is good, in fact some might tell you that you dont even need the plywood! Just attach the foam directly to the benchwork. Personally i dont like this because foam is not very strong and if your doing scenery and lean on the wrong spot of your layout, you’ll go right thru.
So yes, IMO, having the 1/4" plywood as a sub-base with a 1" foam base is a very good way of doing it. The only reason to add more foam is to add foam where you want to add hills and terrain changes.
I would go with 2" so that you can cut rivers, gulleys, etc into it will still maintaining at least 1" all over.
2" is 8 times as strong and stiff in bending compared to 1". (stiffness and strength for a beam are proportional to the thicknes cubed, and inversely proportional to the length).
With two inch thick, the distance between the supports is much less fussy.
If you go with 1" and don’t like it, you can always glue another 1" on the bottom under the plywood - except in areas where you have switch motors.