Benchwork: Plywood, foamboard or both?

[GMTrainNut]

No, I haven't done any testing yet, I've been so absorbed in track planning and getting the layout room ready. But I really want to use foam on top of plywood, makes for sub-grade scenery so easy.

Perhaps the experience I had with it was on a layout where the foam was not secured enough to the plywood. All I can say is as a train rolled by at speed there was a "whooshing" sound, and it competed with all the usual ambient layout noises. I know I said that the layout was foam over ply, but I can't confirm that the entire layout was built that way. Perhaps sections of it were simply foam sheets in an open grid framework?

Sorry if I misled anyone or took the topic in an errant direction.

 

[rcduck]

And now words of advice from a newbie ...

Just finished my benchwork. I used a 2X4 outer frame with 2X3 bracing. Then I laid foam over the top of this thinking it would make it easier to wire (must have read it somewhere). Looking back now, I wish I did at least a 1/4" sub-base. Some of my lower areas (thinner foam) flex under weight. It's fine where I have 2" foam but where there is 3/4 I worry about the movement.

My 2 cents

Randy Duck

 

[videobruce]

Sounds as excessive frame thickness with too little support in between.

 

[rcduck]

Sounds as excessive frame thickness with too little support in between.

Pretty much...

Did I mention Im a newbie First layout.

See here:

http://www.modelrailroadforums.com/forum/showthread.php?t=30629

Randy Duck

 

[rustyfawcett]

You just answered your question. I haven't seen/used Homosote in 50 years. Is that still made??
Concrete floor, hard walls vs carpeted room? Sure there is a difference. You mean expected on a plywood base don't you?

The Home Depo's around here still sell it

 

[Truckload]

I am in the process of building, and will be using 1/4 inch birch plywood under 2" foam, with supports every 24". I have seen a local layout using 5mm luan plywood under 2" foam, with supports every 16" and it is so strong you can stand on it.

I am using slightly thinker plywood, and spreading out the supports to 24" because I do not plan on every standing on the layout!

 

[Hank4014]

I'm about to start a 3'x4' N-scale layout that will not have legs, and will roll out from under a bed. My plan is 3/8" plywood, with 1"x2" pine framing. Laying my track on cork.