What are the best materials for supporting a foam based layout.

[rogergperkins]

  I am contemplating a new layout which I envision as being composed of a 4 ft x 20 ft section with two 4 ft x 8 ft peninsulae sections
perpendicular to the long section, i.e. a large C.

The current layout is on 2 inch extruded polystyrene over a plywood base.

I am searching for options using the 2 inch extruded polystyrene on a wooden frame. 
What construct works for such a frame? 
Thanks.
Here is the track plan:

[jdcolombo]

Hi Roger.

I've never used extruded foam as a layout base, but I'm a huge fan of L-girder benchwork as an overall structural base.  It's extremely strong, easy to construct, easy access to stuff underneath, and easy to "flow" with whatever track arrangement you have.

Here's a photo of the L-girder benchwork I used for Bellevue Yard on my layout (the yard was simply laid on the 1/2" plywood base):



This benchwork is 2' wide X 25' long supported by 2 x 2 legs every 6'.  I weigh 180 pounds, and I've climbed on top of this benchwork to work on stuff with never a worry about collapse.  I also have a peninsula that is 40" wide by 20' long, made essentially the same way: two L-girders spaced 30" apart, with 1x4 L-girder risers attached to 2x2 joists every 24" or as needed.

It seems to me that you could use L-girders with interim supports for the foam, but I've always used plywood as my sub-roadbed with either nothing (track directly on the plywood) or cork as the roadbed base.

John C.

[HuskerN]

Roger, I posted a "best practices" article on my blog with lots of photos.  Specifically, it illustrates my bench work from previous layouts, and my usage of ripped plywood as an alternative for dimensional lumber.  I like an open grid with whatever size of 1 by x, and then plywood on top or cookie cutter with risers.  I prefer the solid base of plywood for the track base.  I am by no means an expert, but after 4 completed layouts, I have found what works best for me, and it is a consistent winner.

Here is the article:  http://www.nscaleaddiction.blogspot.com/search/label/Best%20Practices

and a couple photos from that article:







HuskerN
www.nscaleaddiction.blogspot.com

[DKS]

"State of the art" is a tricky phrase, as is "best practice," since no one has successfully proven any one approach is superior to all others. The realm of benchwork is populated by a wide variety of different techniques, and you'll find there will be champions of particular types. L-girder is a very old, tried-and-true method that, while somewhat tedious to fabricate, produces solid, predictable results. I used the classic L-girder method to construct a substantial layout many moons ago--





Some have migrated to the combination of a plywood base supported on a simple 1-by open grid and topped with extruded foam, which offers a number of advantages over other methods, as well as some disadvantages. And then there are a few, like myself, who have now completely broken away from using lumber or any wood product and instead employ steel framing materials, topped with extruded foam. I had begun a rather large layout using this technique, and reached the tracklaying stage before I had to abandon the project. I can say it has a great many advantages over almost any other style of benchwork, although I won't go so far as to say it's the "best"; I'll simply say it was the best for me. (I wish I had photos of what I'd built; I hadn't taken any, and I'm still trying to track some down from friends.)

There's no clear-cut winner; your choice depends on your preferences, skills, budget, access to materials, track plan, environment, and a host of other factors.

[Sokramiketes]

For 2" foam on a plywood frame, this construction is pretty good.  You'll have 1/4" plywood to mount tortoises/electronics/etc under the layout and if you go the extra distance with masonite spline roadbed, you'll have a strong base for the track as well as foam surrounding it for scenery. 

If you're doing a lot of over/under trackwork or level changes, the cookie cutter plywood base might work better, but if you're modeling something flat like the midwest, this will work well.

[rogergperkins]

This is a hand sketched track plan on quadrille paper.
Dimensions 4'x20' for top section and 4'x8' for each of the peninsulae.
I have done L-girder in the past and had the plywood underlay, but know it is an overkill structurally.
Thanks for suggestions. 
The track is Kato Unitrack which I already have and have used on a larger layout in the past.  Kato turnout machines are built into the turnouts.
I already have the Walter's indexed turntable as well. 
My thought is to use the 2" extruded polystyrene, i.e. possibly reuse some.  Five 4x8' sheets will be needed. Current layout is on plywood which can be recycled to construct the frame. Just a matter of cutting to size from material in inventory.

[DKS]

Roger, in looking at the sketch you provided, I can see a number of potential issues. First, the benchwork is four feet wide, which will create reach problems, unless the layout is entirely free-standing with access to all sides. You have a large yard located the furthest from the front of the layout; this will create an enormous access headache unless, again, the top is not against a wall. And there are a number of track planning issues to be resolved, but that's for another discussion altogether. I would recommend moving away from the four-foot form factor and think in terms of using three feet as a maximum, with narrower sections for visual variety and better access. Also, with a 20-foot length, you could get more layout for your money by going to a G-shaped plan.

[rogergperkins]

David, I recognize the width of 4 feet being a challenge unless the total layout is an island with access from all sides.
Also my plan is to use much shorter legs or supports so that even at my 5'8" height, I can reach in.
I have enough structures currently including Union Station and city buildings as well as industry to "populate" the proposed area.
Green area is to accommodate a neighborhood setting I currently have modeled.

The plan is also smaller that one I had in our previous home with a full basement area.   
The yard is one I currently have with turntable and round house.  The top or backside is accessible, so the a maximum 2' reach.  Freight yard at top,
and passenger yard accessible from "front side". 
Modeling building locations off layout and then placing into position is already a practice I have used for many years.

[DKS]

Just to provide some food for thought, your same space could support a layout like this, which offers a lot more bang for the buck--

[rogergperkins]

I agree with your, correct estimate that my maximum reach is about 30". 
 All of the track on the posted plan is within my reach.  Height of the layout surface is 40", no greater.
This will be my sixth or so home layouts in 38 years, so I am designing it for maximum enjoyment at age 73 year plus.  Hope for another 27 years of modeling.
I already know I like the extended design because I built and reassembled an earlier layout 4 times during a 28 year period as we moved to new homes.

Back to the matter of what would be considered "best practice" for the bench work aspect of this layout. 
My thought is plywood side frame boxes 4 feet wide and 8 feet long with cross members for support at 16" intervals.
I evaluated using a folding leg system and still retain that as an option.

[daniel_leavitt2000]

Would that be the Worcester Union Station from N Scale Architect?

For me, state if the art would be use if non-warping, heat, water and corrosion resistance. I came up with styrofoam-on-PVC bench work as a light weight alternative to wood. It is strong enough to lean on and light enough to pick up very large portions by hand. It also happens to be recyclable.   

[rogergperkins]

Here is the Union Station and some building adjacent to it on my current layout. It is the kit from Walthers.   The Union Station and 5 or 6 blocks of city buildings would be located along the "top" section.  Most of the buildings are DPM kits.


This village would be located on the right module.  I want to add more scratch built replicas of local hometown businesses to that scene.

[rogergperkins]

Neighborhood to be recreated on lower left area shown in green.

[Ed Kapuscinski]

None! Lol.

It won't work for what you need, but don't underestimate the power of simple shelf brackets, doors and Styrofoam.

In fact, there is an a$$hat approved article in N Scale all about it.

[SkipGear]

Roger,
 For simple install, a combination of hollow core doors would work well in this case. I know your layout is water level so there are no grades to deal with.

My preference is a simple open grid of the material of your choice (1x3's, Plywood, Metal stud, ect.) with a roughly 18" to 24" grid spacing, nothing larger. On top of that a sheet of 2" thick high desity foam or more. I make grades in cookie cutter form with thiner foam as the roadbed.