My 4x8 table has 1x3 joists every 10.5 inches. I was planning on putting a thin sheet of pressed fiber board over the joists, and then foam on that, but now I'm wondering if the fiber board is necessary.
Is 1" pink foam sturdy enough to serve as the base of the layout, if it's supported every 10.5"?
Thanks!
I use 2-inch foam supported every 16 inches. It's very stiff. I would think 1-inch foam with your closer supports would be no problem, particularly for HO. O-gauge, with heavier engines and rolling stock, probably needs 2-inch.
It takes an iron man to play with a toy iron horse.
FEH
I have seen 1 x 4 pine framework with joists about every 12" with one inch foam glued to the top. It should be sufficient. Most of the new Dow Foam has a vacume wrap attached at the factory that increases the rigidity. Once you glue it to the frame work, it becomes part of the framework. You're not going to be standing on it.
I have some small sections on 1". They are easier to get switch machine wire in. They are a little flimsy. For the 4x8 roundhouse table I used 2 ". If there are no switch machines underneith it is easier. With switch machines you will probably have to move a stringer unless you planned better than I ever do.
My self, I would use the sub base just in case you put your hand down where you should not. Rather be safe than sorry.
Cuda Ken
I hate Rust
I use 1" foam in "layer cake" fashion throughout my layout. My yard is on a lower level and uses 1" foam supported every 12" by 1x3 crossmembers. It's very rigid and works fine.