Using foam board as under layment

[jjdamnit]

Hello All,

My pike is a 4'x8' "Table-top" with limited access- -actually no access- -under the pike; it sits on the bed in the computer-/spare bed-/railroad-room.

The construction is 1-inch foam on top of 1/4-inch plywood over and open grid frame.

I adhere the foam to the plywood with wood screws topped with finishing washers. These washers prevent the heads of the screws punching through the foam.

For roadbed I use Woodland Scenics foam (add snarky comments here).

The foam roadbed is held in place by clear silicone caulk.

For the curves I use T-pins along the centerline to align the curves and then more T-pins to hold the roadbed in place while the silicone caulk cures.

I use #19x5/8-inch wire brads; available at any hardware or home improvement stores to hold the track in place for testing.

Once the trackage has been finalized I ballast, with the wire brads in place. Once the ballast has dried I pull the brads for reuse.

Hope this helps.

[bearman]

Use the foam.  It will give you option in the future when you decide, and you will, to tweak the sceneray with a river, creek, bridge etc.  In fact, us two inch foam.  I used one inche and wish I used at least two inch.