Plywood or extruded foam as a base


trainstop

Member
I am starting a new project and I am not sure as to what should be the base. I have 1/4 plywood as the solid base with a 2" extruded foam on top of the plywood. I have read some post that just use the extruded foam and lay their track on top of that while others lay the track on the plywood and use the foam for around different areas of the layout. This layout is a bedroom layout with a |_| shaped design with the | areas as 10' and the _ being 13' long. I have seen some great layouts but nothing detailing how the initial layouts were started.
 
Trainstop,

The first thing I might point out is your use of 1/4 ply, personally for a "table top" benchwork that you are talking about I wouldn't use anything thinner than 1/2 ply and probably 3/4".

Building a layout on table top benchwork can be done a couple of ways. One way is to lay your roadbed directly onto the ply then build your scenery up around it using foam. A better way though (my opinion only) is to lay 2" foam on top of the ply. To begin with, the foam will deaden the sound a little but will also give you the base for your scenery. It will allow you to have scenery that goes up AND down from your track level.

If you are asking about the benchwork though, it is recommended to build your "framework" out of 1" X 4" timber locating your cross members no further apart than 24" centers, 16" centers would be better and the absolute minimum if you are going to be using 1/4" ply regardless of whether you put foam on top of that or not.
 
I think that first you have to decide what you want the finished layout to look like . If you want lots of mountainous terrain plywood and girder construction would probably suit you best . It allows for lots of elevation and contour change. If you are looking for a mostly flat/very little elevation change , then the foam may be a better choice for you.
 
I'll second what Tony said about the 1/4" plywood. That is more for a laminate surface where it has a glue attachment to the surface it is in contact with. Left to it's own support, there will be a lot of warping, which, if you want rolling scenery, that's the way to go, but your trains won't work to well.
Extruded foam is great for building scenery. If you have to stack it, you will need to use plywood in between each layer so that your glue will dry. Without the plywood, the glue will take weeks to months to dry as there isn't any airflow. I used 2" x 2" squares of thin plywood just scattered across the foam board to provide a good foundation. Nothing really elaborate, just spaced about 3' apart on large pieces of foam or closer as needed for smaller pieces of the foam board.
Here is a large mountain on my empire that was built with stacked 2" thick foamboard. After the basic form or the scenery is established, I put a layer of screen over the foam using brad nails to hold the screen in place. Ya only need to push the 2" brads through the screen and into the foam board. They hold it in place well enough to apply the layers of wall plaster.
The top of that mountain is a little over 7' off the floor.

Mountains5_zpsb62db2b2.png
 
Last edited by a moderator:
As long as you have a sturdy frame (LOTS of 'joists') and are securely fastened you can probably get away with 1/4 inch, 5/8 would do. Especially with the foam, tacked securely also of course. 'Sag' over time should be minimal to nonexistent. If you don't have something specific in mind, put down a 'parking' yard for the stock at one end on the ply and foam base at 'level zero' and just 'go for it'! Grade up onto more foam and/or out into layout land! Every space and shape has an 'optimal' layout, you just have to find it! Try different ways of securing he track and go with your gut! You are the 'boss' and 'we do the best we can with what we have'!
 
I had fat fingers. The plywood is 3/4" with open grid as the bench work with the plywood on top. The different bench works are at different levels so the there will need to be some type of elevations. Some will be mountains and some will be bridges to connect the different elevations.
 
If you are doing a lot of elevation changes with your track, then using plywood and a cookie-cutter technique is easier. Cutting a lot of ramps into foam is tedious and messy.
 



Back
Top