# Foam board questions



## Hotrainewbie (Feb 14, 2021)

Hi, I have finally gotten around to beginning work on my first layout. I already have the tables and wood boards set up and attached. Now, I need some help with foam. It has come to my attention that a layout should have foam boards on it to allow for less noise and more flexibility for adding details. I use Bachman EZ track and only plan on cutting a light creek into it so I don’t think I need that thick of board. But, for those of you that actually know how this works, what thickness of board would I want to use and how do I stick it down to two 4x8 boards of OSB?


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## Severn (May 13, 2016)

I seem to recall two thicknesses of the "pink" foam at HD and one is probably 1" and the other is somewhat thicker. I mean either could work and if you need a particular depth, you could stack em up. There's one kind that has foil backing, I'm not referring to that one ...


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## Ron045 (Feb 11, 2016)

I used 1" foam and screwed it in place with drywall screws. Makes removal of some pieces simple and easy for water or any other terrain changes.


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## JeffHurl (Apr 22, 2021)

I forget which scale you will be using. I would get at least 1" thick, but would suggest a 2" board. I'm modeling in N scale. The creek I did here was actually a void where I cut a winding line across a 1/2" thick piece on top of a 2" piece.



























You can see in the picture above that I also carved down into the 2" board to add more depth to the stream.


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## OilValleyRy (Oct 3, 2021)

I previously used 2 inch foam glued down with regular elmers white glue, though silicone caulk would add to sound deadening better than hard glue.


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## Jscullans (Jul 8, 2019)

I went with 1” tongue and groove for a tighter joint and glued it down with silicone. If you go that route then you’ll need a couple paint cans to weigh down the foam so it doesn’t end up with a high spot or something to cause derailments. Keep it in mind good benchwork is key to a good running layout. If the benchwork isn’t straight then you’ll have nothing but issues down the road and I would imagine it’s frustrating. I built a grade into my layout but it was intentional and is like 8 feet long so that’s also helpful


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## OilValleyRy (Oct 3, 2021)

Also, I need to say…4x8 sheets if foam can actually warp. Who knew!? Not me until I got one home from bLowes and said what the frakk?? Not from moisture I don’t think but from how some big box knuckle heads store them.


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## JeffHurl (Apr 22, 2021)

OilValleyRy said:


> Also, I need to say…4x8 sheets if foam can actually warp. Who knew!? Not me until I got one home from bLowes and said what the frakk?? Not from moisture I don’t think but from how some big box knuckle heads store them.


Yeah, I had the same issue with bent boards from Menards. They were 1/2" sheets where the edges were bent from being strapped down. I didn't notice it until I went to use them, and they didn't lay flat.


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## mesenteria (Oct 29, 2015)

Hotrainewbie said:


> Hi, I have finally gotten around to beginning work on my first layout. I already have the tables and wood boards set up and attached. Now, I need some help with foam. It has come to my attention that a layout should have foam boards on it to allow for less noise and more flexibility for adding details. I use Bachman EZ track and only plan on cutting a light creek into it so I don’t think I need that thick of board. But, for those of you that actually know how this works, what thickness of board would I want to use and how do I stick it down to two 4x8 boards of OSB?


The extruded foam board is noisy. It acts like a drumhead. However, the story doesn't end there. Not by a long shot. 

What deadens sounds effectively is dual or triple density of abutting/mating layers. So, if you run plastic ballast EZ-Track on foam, you'll find it very noisy. Put a layer of caulk between the fake ballast AND the supporting frame members for the foam and you'll find things quieten quite a bit. So, the idea with Homasote, soft foam roadbeds, plywood or pine/spruce strips for roadbed for those who want to deaden the roar of passing trains that don't have sound-generating digital devices on board is to use dual densities at the very least. Caulk works great, but so does a thin layer of cork underlay, or foam underlay, even cardboard would help quite a bit. It's more work to construct roadbed this way, but for me the results are worth it.

BTW, you can test this yourself: the absolutely deadest noise on anyone's layout will be a bridge of any construction. Properly installed, on 'shoes' or on stripwood abutments, your trains running over a bridge will be dead quiet...with mechanical drive sounds if it's a noisy drive mechanism and with any digital sounds.


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## JeffHurl (Apr 22, 2021)

mesenteria said:


> The extruded foam board is noisy. It acts like a drumhead. However, the story doesn't end there. Not by a long shot.
> 
> What deadens sounds effectively is dual or triple density of abutting/mating layers. So, if you run plastic ballast EZ-Track on foam, you'll find it very noisy. Put a layer of caulk between the fake ballast AND the supporting frame members for the foam and you'll find things quieten quite a bit. So, the idea with Homasote, soft foam roadbeds, plywood or pine/spruce strips for roadbed for those who want to deaden the roar of passing trains that don't have sound-generating digital devices on board is to use dual densities at the very least. Caulk works great, but so does a thin layer of cork underlay, or foam underlay, even cardboard would help quite a bit. It's more work to construct roadbed this way, but for me the results are worth it.
> 
> BTW, you can test this yourself: the absolutely deadest noise on anyone's layout will be a bridge of any construction. Properly installed, on 'shoes' or on stripwood abutments, your trains running over a bridge will be dead quiet...with mechanical drive sounds if it's a noisy drive mechanism and with any digital sounds.


Most definitely! I used a 1/2" layer of foam on top of a 2" layer. I did this so the 1/2" piece would be the "roof" of a couple tunnels and also be the "ground level" of the trains running at elevation.. I inadvertently made, what I would call, a passive radiator like used in a speaker cabinet to accentuate the sound of the woofer. I can clearly hear the train go over the tunnel...

But I'm OK with the noise. I prefer the natural noises of my trains running over the DCC sounds of the engine. The only noises I like from the engine are the horn and bell. Although, I do enjoy the idling sound of teh diesel that comes through on DCC... but once the train starts moving, the engine noise becomes monotonous.

I'll gladly take the noise in exchange for the simplicity of carving the boards into terrain.


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## Severn (May 13, 2016)

The plastic base track is just noisier than the flex as has been discussed many many times here and elsewhere, and there doesn't seem to be a way you can really mitigate it 100% without changing the kind of track. Using my phone with a db measuring app on it (uncalibrated) -- I measured about 10 db drop between a section of plastic track and flex track I have with something running over it in HO scale.

In my case the flex is on cork, 1 or 1.5" pink foam, then plastic table tops. The plastic track at the moment just sits on either the foam directly or on some heavy felt, then the foam. I'd say that at relatively slow speeds its not that noticeable but you may wake up one day and decide that track noise is just too loud at any speed. Over the years there's been many discussions about this on various train forums and folks suggested all sorts of things to make it better. I've tried a few of them and found that by and large they didn't seem to make enough of a dent in that 10 db gap to be worth it. I even tried filling the plastic base with some materials of various kinds which I thought would surely "do it" -- but this didn't do it either.

Having said that, flex track is a pain in the butinski honestly to put down unless everything is pan flat -- well and it still could be a pain, that's just my theory.


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## sjm9911 (Dec 20, 2012)

I dont use it for sound deading. I use it because for me its just easier , and make a quick scennery. I haven't gotten to the realistic part of modeling stuff. But I want it to resemble something. So foam board it is. I may make some cavrans and stuff later. As you can see its a mess. But it started as diffrent layers of foam. Carved and painted. Last picture is of the slopes the outer 2 lines will use. So diffrent slopes.


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## Severn (May 13, 2016)

Yeah I got it because I decided to try my hand actually building layout structures instead of just having some track loop around table tops -- and it was cheap and readily available. I think it has many pros, and some cons -- but that's the same as everything.


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