What the best

[Anonymous]

Thanks guys

[SpaceMouse]

I thought about using just foam on steel studs, but if you take too much of the foam away to create a gully or wash, the foam might be a little weak. I'm thinking I might have an underlay of 1/2 plywood, sealed to help prevent moisture/heat expansion.

[tstage]

I would agree with Jacob. Extruded foam insulation (EFI) on top of 1/2" plywood makes for a great foundation. The plywood gives the layout a rigid surface to mount switch motors on. The EFI (~$25 for a 4 x 8', 2" thick piece in NE Ohio) is lightweight, easy to cut, and "stackable", so that you can build mountains, ravines, or any other sort of uneven terrain to make your layout a little more interesting topographically.

A lot of folks will first build the benchwork, then lay the plywood on top of that, then add the EFI on top of the plywood. The foam is also easier to glue to or add trees and ground cover to. The EFI is stiff enough for rigidity but pliable enough to add trees, bushes, and ground covering to just by pushing them into the foam.

Tom

[Anonymous]

Thanks i was thinking that to but wasnt sure

[Anonymous]

I don't know if it is the best, as that is probably a question of perspective. I think most around here will probably tell you extruded foam. It is likely the simplest way to create contours in your topography. I intend on using this foam atop a plywood base.

Jacob

[Anonymous]

What is the best base for my layout, wood, styrofoam, or something else?