Hmm... Flat or Multi-Level Layout? Foam or Plywood Base?

Kisatchie May 25, 2022

  1. Kisatchie

    Kisatchie TrainBoard Member

    I really need to get busy building my layout. I have a 9 x 10 foot room, so all I need to do is decide whether to keep the track at "sea level" or have grades. Also, I'm not sure if I should use foam or plywood for the base.

    In all the decades I've been in model railroading, this is my first real layout. Therefore, I would like to avoid problems if I can.

    Any comments pro or con to the questions I asked above?

  2. MRLdave

    MRLdave TrainBoard Member

    Tough question........if you use a foam base, it's easy to carve it to represent ditches, gullys, ect. On the other hand, plywood allows you to "cookie-cutter" your grades to provide smooth transitions. I'd say your first decision is whether you want grades, go with the foam. It gives you more scenery options. If you want grades, go with the can still use foam for hills and such, but trying to carve grades into foam is difficult and messy option. Not that it matters, but I went with plywood.
    gmorider, BNSF FAN and Kisatchie like this.
  3. BigJake

    BigJake TrainBoard Member

    Grades can be either carved into foam, or you can use the flexible incline strips from Woodland Scenics, on top of and/or underneath/between foam sheets.

    Plywood cookie cutter is a tried and true technique, but you end up having to add something to bridge/fill the gaps between different elevations along the edges of the cut lines, whereas the stacked/carved nature of foam does not have such gaps to fill in most cases.

    You can also "cookie cutter" foam sheets, and you can use either graduated foam blocks or WS flexible incline strips between/underneath the foam sheets, to control the grades.

    I'm planning on using foam for my upcoming layout (currently in prototype stage on a hollow core door with Unitrack Viaducts/piers for inclined/elevated trackage). I've already tweaked the elevated track paths some, so I'm glad I'm prototyping before I commit to cutting foam. Untrack and its viaducts are not cheap, but I already had a sizeable collection from former layouts that never got past sitting atop an old kitchen table.

    Anyway, either plywood cookie cutter or foam base works well, so "pick your poison!".
    gmorider and Kisatchie like this.
  4. wvgca

    wvgca TrainBoard Member

    i used a combination of the above ... 3/8 plywood for the base, in a sort of cookie cutter form, which allowed me to have up nine inches of vertical runs .... on top was foam, mostly two inch, which was also used for inclines / declines as needed, [cut as needed with a homemade foam cutter], no homasote or other ballast forming, it was all done on the foam base, used dap alex glue to hold it down, and thinned dap alex to hold the ballast in place ... mind you this was for a back woods 1890 era small geared steam railroad which i called the 'Squirrel Creek Railroad' , just about nil for electrical on it, manual caboose ground throws, non powered frogs..
  5. mrhedley

    mrhedley TrainBoard Member

    If you go the foam route, consider using 2 layers of 1" foam rather than a single 2" base layer. It makes transitioning to different heights much more manageable.
  6. Moose2013

    Moose2013 TrainBoard Member

    Moose was happy building multi-level based on open-grid bench work, plywood "cookie cutter" plywood and 1x3 risers. Just a moose thought...
    Pfunk, gmorider, Sumner and 2 others like this.
  7. Kisatchie

    Kisatchie TrainBoard Member

    Unfortunately, Moose, I'm not a carpenter.

    Hmm... the Carpenters
    are my favorite music
  8. JimJ

    JimJ Staff Member

    I use a 2” base layer of foam for sufficient rigidity and then some one inch stuff as needed for scenery, grades etc. Very lightweight and easy to cut, carve and shape. Easy to make changes and scenery is a snap.
  9. Doug Gosha

    Doug Gosha TrainBoard Member

    With my current layout, I debated going with plywood or foam. I eventually settled on plywood, in spite of the attractiveness of the lighter weight of foam (of which my original Treble-O-lectric layout was made in the early sixties) because I knew I was going to be using under table switch machines and didn't want to mess with making their operation reliable with a foam base.

    gmorider, Helitac and BigJake like this.
  10. Todd Hackett

    Todd Hackett TrainBoard Member

    To keep problems away - don't build a layout! That said, problems happen, you just need to get through them no matter what you use to build the thing. If you need something light weight and sturdy, foam over 1/4 or 3/8 ply on top of 1x3's or 1x4's. If you want to stand on it, 3/4 ply over 2x4's. Play around and figure out *what* works for you. You do not have to be a carpenter to do this. When you screw something up ( you will ) chalk it up to that learning curve and move on. After awhile, and enough practice, you may think of building that wanted garage!
  11. Kurt Moose

    Kurt Moose TrainBoard Member

    Using foam base will keep the trains quieter as well. Won't sound like an old Lionel trainset!
    BNSF FAN likes this.
  12. BigJake

    BigJake TrainBoard Member

    I suppose we should ask whether this will be an around-the-room (along the walls) layout, or an island layout. The former gives you more running length, while the latter can be built on a Hollow Core (interior) Door, or a sheet of plywood. Either way, limit yourself to 30" reach-in distance. If you build the layout and then move/fasten it against the wall, then depending on your body size and arm length, you might extend that to 36". Just beware that trains seek out the farthest reaches at which to derail.

    You can purchase banquet table legs than can be fastened to the underside of plywood or HCD, though you will need some 1x lumber glued flat to the bottom of the HCD, then screw the legs to the lumber.

    Depending on your budget, there are benchwork manufacturers that will build the benchwork to your dimensions in pieces, ship it to you, and you assemble on-sight. They advertise in the magazines.

    You might also consider a modular layout, assembled out of standardized modules which you purchase (or build) and scenic your self. If you have a nearby modular RR club, that might be a very good way to start. This mostly applies to N scale, but I believe there are HO scale modules too.
    gmorider likes this.
  13. BoxcabE50

    BoxcabE50 HOn30 & N Scales Staff Member TrainBoard Supporter

    Around the room, along walls? (Windows and doors to cross?) Freestanding? Permanent? Portability, in case of any future move? Did you have any sort of theme in mind? Urban? Rural? Any special features? (Water, hills/mountains?) Foam is nice, but still needs a certain amount of wooden support.
    gmorider likes this.
  14. BigJake

    BigJake TrainBoard Member

    Room features and their relative locations, like the entry door, closet door(s), and windows will impact your layout shape, especially if you need to maintain access/function of closet and/or windows/draperies, etc. Can you incorporate closet space into your layout, or for a workbench, etc.?

    A local carpenter (or friend with carpentry skills) should be able to help you build benchwork, whether you want it free-standing or attached to the walls.

    Do you plan to use this room only for the layout, or for the hobby in general? Do you need a desk/workbench in the room/closet, along with your layout?

    A layout can be as simple as a Hollow Core, interior passage Door (HCD) spanning a couple of unfinished kitchen or bathroom cabinet bases or workbenches (or one big one). Check with your local supplier to see if they have "scratch and dent" doors and/or cabinet bases available at a discount.

    Foam is an excellent sub-base on top of an HCD. Extruded foam panels are stronger and easier to work with (IMHO) than expanded foam (e.g Styrofoam) panels. It can be stacked and sculpted easily to create any terrain you might want. Foam also isolates the noise of the trains rolling on the tracks, which is substantial when track is just laid on top of a HCD, even with a layer of felt between the track and the HCD (personal experience). If your track plan includes different elevations and grades, you can use Woodland Scenics' flexible styrofoam ramps, or carefully cut your own out of 2" thick foam. Expanded foam is available in 1/2, 1 and 2" thicknesses (and thicker in cold climates). A 2" base layer gives you substantial room to carve out terrain below base track level, and is cheaper to build up terrain height. Thinner sheets are sometimes easier to create smooth rolling terrain, but are more expensive per depth of terrain you need (a 2" 4x8 sheet is considerably less expensive than two 1" sheets.) Keep in mind that most terrain need not be carved from a continuous sheet of foam. You can piece together successive layers using scraps created from making previous layers of terrain.

    Note that if you plan on using under-layout switch motors, some don't tolerate the motor being far below the switch. This can be a factor of how thick your foam sheet(s) need be below the switch. You can hollow out lower foam layers underneath the switch, to create a higher level cavity ceiling to which to mount the motor/linkage. You may need to use a thin piece of plywood glued to the underside of the foam, to which you mount your switch machine. I use Unitrack, with the switch motors built into the attached roadbed, and avoid all that.

    Wiring can be run in channels carved in the bottom of the lowest layer the foam (i.e. in between bottom of foam and top of HCD), or you can run the wires all the way through holes in the HCD, and connect them together under the HCD. I plan on the former, so I will not glue the bottom layer of foam to the HCD. Another reason to use a thicker bottom layer of foam, is so it retains decent rigidity on its own when lifted above the HCD. I haven't decided how to handle facia boards around the edges of the layout, whether to glue them to the edges of the HCD, or to the edges of the foam. Probably the latter, but we'll "run off that bridge" when we get there.

    As in most hobbies, expense vs effort and/or time is a tradeoff only you can decide for yourself.
  15. Dogwood

    Dogwood TrainBoard Member

    Type "Model Railroad Benchwork" on Youtube. I think that will help you. I don't know of any model railroader that only builds with foam.
  16. BigJake

    BigJake TrainBoard Member

    Or type that into your favorite internet search tool, and it will also show you (at least one) company who sells modular/custom benchwork, for those without woodworking skills/tools (all you need is a screwdriver to assemble it.)

    Having a few basic woodworking hand and/or power tools (saw, drill, square, etc.) and basic knowledge to use them (internet, friend/neighbor) will save you a lot of money, and not just in this hobby.

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