Benchwork Question

[pj1775]

Hello:
Can anyone give me the pros/cons of using insulation board once the benchwork is constructed. Is there any risk of sagging and if there is that risk, how much spacing of braces would I need to prevent this from occuring. OR is using foam as the base just a bad idea, and should I use homosote or plywood instead, and use the foam to build terrain & grades? .

Thanks,
PJ

[johncolley]

If using 2" foam you should support it about every 24" If thinner move the supports to around 16" centers.

[pj1775]

Thank you for the information. I definately would prefer to use the extruded foam as the base. I find it be much more user/designer friendly. Thanks for the help!

[orsonroy]

There have been several good discussions on this forum on using foam as a layout construction medium. Do a search for "foam", and a LOT of data and opnion will come your way.

Personally, I love foam as a layout construction medium, and will never return to wood-based layouts. My last layout was a 10x25 three level, and my next will be a 14x25 double level. Basic layout construction was 2" foam, laminated to 1/4" Lauan plywood, mounted to the walls with metal L brackets (16" centers). While not strong enough to walk on, it was plenty strong for toy trains!

[pj1775]

Oh I see...so you use the 1/4" ply beneath the foam?

[selector]

Yes. The thicker the foam, the less thick the plywood, as you might have guessed. Although my set-up is different, many guys here report that 2" foam really needs no support unless you will have large spans below it with heavy objects atop it...including you. Some like stacking the 1" stuff and then carving it to shape topography, while others go right to the 2 and 3" stuff so that they don't have to glue and wait for drying.

The idea of the foam on top is that you can shape it to get depressions, and stack layers to get elevations.