Updating my layout to styrofoam

Model Railroader Layouts and layout building
1

Yesterday, I removed the last of the plywood from my layout in preparation of replacing it with styrofoam. The track baseboard is cookie cutter plywood and that will remain.

I have read that I should lay down a piece of thin plywood on top of the layout support frame, to which I should glue the styrofoam. This is to reduce noise from operating trains. Apparently, the foam alone works as a noise amplifier.

First question, is this true and therefore is it necessary to laydown the plywood sheet first?

Next question: if the plywood is necessary, what to use. I can get 1/8". 1/4" and door skins. At my local lumber purveryor, the mahogany 1/8" is noticably flimsier than the oak 1/8" sheet. What do you recommend?

Thanks in advance for your thoughts.

2

I just lay the foam in. I put just enough support to hold it in place. With 2 inch foam I span 24 - 36 inches. With 1 inch I try to support every 18 inches to 24 inches. One of the advantages is that many of my mountains and scenes are not glued in so I can lift the foam section out for construction on the work bench and for access later. One whole side on my canyon is removeble in 5 different sections.

3

Thanks for the reply. With using just styrofoam, you don’t find you trains generate a lot of reverberating noise when they run across it?

4

Yes, foam is noisey. So are prototype railroads. I am one that likes the noise. One of the great bridges in the Bridge book actually built a sound amplification box in the bridge. That struck me as a good idea. Trains are loud, so one more good thing about foam for me.

5

I to enjoy the “noise” that I get and I use all metal wheelsets. All of my engines are also equipped with DCC sound. My layout is built in 2’ x 8’ sections with a frame of 1x4s, on 24" centers with 2" blue foam “Liquid Nails for Projectes” used to secure the foam to the 1x4 frames. I cut out a 3 1/2" square of Medium Density Fibreboard 3/4" thick and put it where every turnout will be installed using more of the Liquid Nails. This facilitates the installation of a Tortise or a Caboose ground throw. The sound of the train does not seem to change noticibally when crossing over these squares of MDF. The 2’ x 8’ sections are connected togeather with carriage bolts with allignment pins, and my layout is a 20 by 23 foot walk-in L shape. It makes for a transportable (not portable by any means) layout. My previous layout was built using this method and moved (sans blue foam-it was hardshell) all over the world with me in the US Air Force with only minor problems. You just have to cut the rails and scenery at the joints. I did put fibreglass insulation in under the tunnel which is at one end of the L and it sufficiently deadens the sound so you don’t hear the noises from the train whilt it isinside the tunnel.

Paul

Dayton and Mad River RR

Paul

Dayton and Mad River RR

6

Remember, the foam you want is extruded foam, used for insulation in the construction business. “Styrofoam” is the stuff they make coffee cups with. It can be used as an interior filler for hills, but it’s a mess to work with and isn’t anywhere near as rigid as the extruded stuff.

I use the 2-inch stuff with no plywood below it. I use 16-inch centers for my supports, but I’ve got a free-standing table and that also helps for the interior bracing. I also find it convenient to have wood supports that close to mount terminal strips and other electrical stuff underneath the layout. Foam doesn’t take nails and screws well.

7

If I understand your post correctly, you are retaining the plywood base under the track. If so - unless you put foam on top of that plywood and under the track and roadbed, the foam over the remainder of the layout will not affect the sound, it seems to me.

8

"Styrofoam " IS the blue extruded foam, not the coffee cup foam, which is the bead-type foam.

9

The usable foam also comes in green, yellow and pink. The yellow and green are too expensive to buy, but if you find it at a construction site it will work just fine and can be mixed with the others for mountains building.

10

Scott,

I found some pink extruded foam called Formular that comes in several thicknesses and in 2’ x 8’ sheets (easy to transport). Am using a 1" layer as a base over 1/4 plywood, and plan to use some of the Woodland Scenics products for subroadbed and the like.

Also found an adhesive called Nail Power for Foamboard that seems both easy to use and really strong. I found mine at Lowe’s, but other places may have it too.

11

Hi Art great scenery Hope you don’t mind how big of layout space do you have how wide is your benchwork and do you have a track plan love the pictures.

August

12

Hi August. My layout is made from 2 - 4x8s connected with a 2x20 and the canyon in a corner. I do not have a track plan, I just build it, though I layed it out on the floor in blue masking tape to make sure it fit, sort of.

13

Thanks Art

14

Using the foam is all personal preference.

I used the white bead board foam for my base. everyone told me not to, but i forged ahead anyhow.

I built my son’s 4x8 the old fashion way at first, I made the support frame out of 1x3’s then I put a 1/4" sheet of luan plywood on top of it. not 1/2 or 3/4"; 1/4" then I laid down the two 2’x8’ sheets of 2" thick white bead board foam on top. they were just laid there, I had the legs on this by now too. I then took 1"x6" and surrounded the table top making the whole thing flat.

Once i was COMPLETLY happy with what i was going to build, I then cleared off the whole layout and glued the bead board down to the luan sheet with cheap laytex caulk from ACE hardware.

I did this so late because I had the layout planned out, set, up and running, and then changed my mind on it, that allowed me to clear it off, flip the foam sheets over and start clean slate once again. i thought it might be too confusing tracing a new edge lines for the roadbed when there was already edge lines drawn for the layout plan i no longer liked.

I then used the WS foam roadbed on the foam, it is very quiet. I also used some cork, its quiet too, but not as quiet.

once ballasting is done though, there isnt any difference between the two, especially if you ballast the glue method, as the glue will form a hard shell when dry and that shell is what vibrates and creates the noise you hear. anyhow…

unsupported foam sheets will be louder, as they do act as a baffle much like a vibrating speaker does. I did some tests before I decided on how i was doing my benchwork. once the foam sheet was firmly settled down on the plywood, the echoing was gone.

right now, I can run my Proto 2K 0-8-0 around and when its alone and with sound off, you hear it rolling along when its at highest speed, and that noise is the motor noise not the vibrating noise from th