# Do you use Foam Board on top of your Layout Plywood Base?



## JML52 (Oct 19, 2017)

Hello everyone, I'm starting on my first real (off the floor) layout; O-Gauge. I have ordered the Mianne Bench works (4' X 12') and am planning on using 1/2" B/C plywood on the top of it for the base. Most of the layouts I've seen in person have some foam sheeting on top of the plywood, either 3/4" or thicker. Is this a good practice? Better for sound deading? 
What would you recomend? Also, how to secure it to the plywood?
Thanks, I look forward to any and all suggestions.


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## CTValleyRR (Jul 26, 2014)

First of all, understand that there is no right answer here. It's a matter of personal preference, so there is no "wrong" answer.

The primary reason for using the foam is that allows you to create terrain features below the level of the tracks without the need for cutting holes in the plywood. I personally use a minimum of 2" of foam. Any good foam compatible construction adhesive or adhesive latex caulk will work to hold it together. Just be sure you lay it in an S pattern to promote curing.

The foam isn't really for sound deadening. Roadbed material (either cork or foam rubber) under your track will do a much better job than an extruded foam panel -- these can actually amplify sound under the right circumstances. If controlling sound is a primary consideration, than you need to make that part of your benchwork construction as well.

However, I'm one of those who doesn't think plywood is necessary at all. L girders on 18" centers will be more than ample base for a layout. 2" of foam plus L girder joists will hold my 225 pound weight easily. While plywood underlayment gives you something to screw into everywhere, it's not necessary, and it adds cost and weight to your layout.


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## subwayaz (Dec 26, 2009)

For O Scale I would use the foam board on top. However I Model N Scale & HO And just use Foam board only and have no issues. I do use a wood frame


Sent from my iPad using Tapatalk


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## JML52 (Oct 19, 2017)

Thanks Guys,
I failed to mention "if it matters" I'll be using Lionel fast Track and switches. I'll have many questions also on proper wiring of the layout.


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## CTValleyRR (Jul 26, 2014)

JML52 said:


> Thanks Guys,
> I failed to mention "if it matters" I'll be using Lionel fast Track and switches. I'll have many questions also on proper wiring of the layout.


Doesn't matter. You can attach wires wherever, to foam or wood. An under-table switch machine can also be mounted to foam, or in the foam, or to a cleat especially mounted for the purpose.

I find foam easier to go through than plywood, though, if you need to drill holes.


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## Fire21 (Mar 9, 2014)

As CTValleyRR said, the main reason for using foam is generating topographical features below track level, such as roadside ditches, creeks and ponds, and valleys. Pieces can also be stacked and formed to make hills, cliffs and right-of-way cuts through hills. It's a very easy medium to work with. I highly recommend it.


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## JML52 (Oct 19, 2017)

To make a lake or pond as well as similar effects would you go with 2" foam? I plan to make some mountains as well as a few built up hill cuts for the track and a tunnel.
Thanks for the replies "you've got me thinking".


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## Fire21 (Mar 9, 2014)

The pond is made as a shallow depression, then painted to make it look deep before adding the "water" effect...light blue/green for shallow, deeper blues for deep. Be sure to look for videos on how to do it.

I made the mistake on my layout of cutting a DEEP hole for a lake. Had to fill it back in after I learned the right way to do it.


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## Mark VerMurlen (Aug 15, 2015)

If you haven't done so already, you should look through several of the threads under "My Layout" on this forum. Lots of folks (including myself) have documented the construction of their layout. I learned a lot from looking through how other people built their layouts.

I prefer to put my track and cork roadbed right on top of the plywood. However I use the "cookie cutter" method with the plywood so that I can vary the track height and get nice smooth transitions in height around my layout. I use foam to build up or sink down below the plywood supported roadbed for my landscape features. As CTValley said, there's lots of different methods and its primarily a matter of preference.

Mark


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## wvgca (Jan 21, 2013)

i used expanded foam board from 1/8 inch to six or eight inches on top of 3/8 plywood, just glued it all down wIth DAP foam adhesive, been a few years now and all is still good ..


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## JML52 (Oct 19, 2017)

Thanks Guys, a lot of good information here, I think I'll go with the 2" foam on top of the plywood and start laying out some track. I have drawn out several sketches of the layout but I also realize until I can lay down some track nothing is as it will be.
Thank You!


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## wis bang (Aug 6, 2015)

I have used 2" foam on L girders and found the foam works well without plywood. It was easy to build layers up to meet an upper level and them add rock castings made from Durhams Water Putty using more of the plaster to glue the castings onto the foam. 

I did take a section of plywood to cut out an 'S' shaped roadbed that snakes through farm and mountain from one area to another and I'm getting ready to make the foam buildup around this single track up to an industrial area as I wanted to have good support using 1 x 3 pine risers off the 'L' girders. 

The foam makes it easy to add wires anywhere for any reason and I have a dremel router bit to rough out shapes into the foam quick and easy, go for it.


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## Fire21 (Mar 9, 2014)

*Stanley SurForm Shaver*


I have found this tool to be a great shaping tool for use with foam. I use it to form river banks, hillsides, ditches and other topographical features. It is cheap, and has a replaceable blade. It's also handy for some sheetrock work in house remodels!

http://www.stanleytools.com/en-us/p...ls/files-surform/714-in-surform-shaver/21-115


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## CTValleyRR (Jul 26, 2014)

Fire21 said:


> The pond is made as a shallow depression, then painted to make it look deep before adding the "water" effect...light blue/green for shallow, deeper blues for deep. Be sure to look for videos on how to do it.
> 
> I made the mistake on my layout of cutting a DEEP hole for a lake. Had to fill it back in after I learned the right way to do it.


An important point that I will reiterate!

The foam is used to create depth to the SURFACE of the water feature, as a river down in a big ravine. Water depth is simulated by painting to fool the eye. None of the artificial water products I'm aware of work well when layered on too thickly. A 1/8" layer is sufficient to convey the impression of water.


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## Guest (Oct 27, 2017)

I use 1" extruded styrofoam without plywood on my O gauge layout. The foam is strong enough that plywood isn't necessary. I covered the foam with 7/16" carped padding to reduce running noise. I covered that with Woodland Scenics Ready Grass for a semi-finished look right away. This can be covered with scenery materials. This picture shows the table top.









Foam is much lighter and easier to work with than plywood. FasTrack locks together and doesn't need to be screwed down so there really is no need to use plywood. 

I have used this for a few years now with no problems.


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## MtRR75 (Nov 27, 2013)

CTValleyRR said:


> An important point that I will reiterate!
> 
> The foam is used to create depth to the SURFACE of the water feature, as a river down in a big ravine. Water depth is simulated by painting to fool the eye. None of the artificial water products I'm aware of work well when layered on too thickly. A 1/8" layer is sufficient to convey the impression of water.


However, you can also the ILLUSION of a deep body of water by excavating a deep hole with steeply sloping slides and a flat bottom. Then use the painting techniques on the flat bottom to indicate that the center is deeper than the edges. The sloping terrain down to the water will create the illusion that the terrain continues down steeply under the water.


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## Krieglok (Sep 7, 2013)

I use a hollow core door with a base layer of 1" insulation foam board. The tracks are on another level on top of that for below grade effects. I use additional stacked layers to rough out hills. 

I bought some and scrounged more from construction site dumpsters...lots of useful scraps there!


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## flyboy2610 (Jan 20, 2010)

I have a plywood tabletop and 2" of extruded foam over it for adding below grade features, such as my river scene. (Gonna have to finish that one of these days!  )


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## CTValleyRR (Jul 26, 2014)

MtRR75 said:


> However, you can also the ILLUSION of a deep body of water by excavating a deep hole with steeply sloping slides and a flat bottom. Then use the painting techniques on the flat bottom to indicate that the center is deeper than the edges. The sloping terrain down to the water will create the illusion that the terrain continues down steeply under the water.


Yes. The point is that the fake water itself doesn't need to be, and in fact shouldn't be, applied too deeply.


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## Rook (Nov 5, 2017)

CTValleyRR said:


> However, I'm one of those who doesn't think plywood is necessary at all. L girders on 18" centers will be more than ample base for a layout. 2" of foam plus L girder joists will hold my 225 pound weight easily. While plywood underlayment gives you something to screw into everywhere, it's not necessary, and it adds cost and weight to your layout.


Any photos of L girders...or a link to thread or video showing this method. You have to have a frame to hang the girders from?

Thxs


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## mesenteria (Oct 29, 2015)

What you do is to purchase good 1X4 spruce lengths and rip some of them in half down their length, or simply purchase 1X2 If the store sells them, if you don't have the capacity to rip some of the 1X4's. Then, you imagine the 1X4 on its edge, with the wide face vertical, and you place one of the wide sides of a 1X2 on the top edge of the 1X4. I glue and use decking screws to hold it in place, and I normally don't remove the screws. That, when the glue dries, is an L-girder. It's amazingly strong. The L is actually inverted when you have it in place on the layout, and you normally mount two of them in parallel separated by as much as the depth you'd like your benchwork to be.

If you look carefully, you'll see several L-girders in this grainy photo.


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## CTValleyRR (Jul 26, 2014)

Exactly what mesenteria says, only I use 1x4 lumber that I rip in half on my table saw, and 1x3's for the cross members. Since the grain is perpendicular in the two pieces, they are very strong.

His picture above shows a lot more structure than I use. Joists on 18" centers with 2" foam on top will hold my weight (225#) easily. Everything is on the same height on my layout, though (he may be getting there; tough to tell).


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## Rook (Nov 5, 2017)

I think what I am looking for is a frameless benchtop. Modular sections that I can manage from the wheelchair. Weight is a major consideration. The frame appears to be for mounting hardware as much as supporting the layout. I won't be hauling it around town but access to the underside of the layout seems like a requirement?


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## Fire21 (Mar 9, 2014)

Rook said:


> I think what I am looking for is a frameless benchtop. Modular sections that I can manage from the wheelchair. Weight is a major consideration. The frame appears to be for mounting hardware as much as supporting the layout. I won't be hauling it around town but access to the underside of the layout seems like a requirement?


I searched and searched, but couldn't find the thread that deals with building a tilting layout. It's made so that the whole layout tilts up to 90º so you can access the underside for whatever you need to do. Consideration would have to be given for any loose items on top when you were tilting it.

I'd think it could be relatively easily constructed so long as you didn't go too big. Modules would be perfect for this since they're designed to be taken apart...you could tilt one module at any time you needed.


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## Rook (Nov 5, 2017)

I saw this one...http://http://www.modeltrainforum.com/showthread.php?t=134186&highlight=actuator

The ends of the rolling chassis would need to be mounted inside the frame if you had more than one module. What is the biggest issue...alignment? Maybe a key or spline on the mating surface of the modules would help with that.

Initially thought it was more than I want...but it is under consideration.

Thxs.


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## Fire21 (Mar 9, 2014)

Yes, I would think alignment would be the biggest thing...to keep trains from derailing when crossing module edges. I'd think clamp or gently bolt the modules together, tilt them together to ensure they move equally and then lay the connecting tracks to ensure they were even.

But I'm sure there'd be geometry involved in moving pieces that would make things come out not aligned. That sort of thing always happens to me! hwell:

It'd most likely take some experimentation, but, hey, that's part of this hobby!


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## Mr.Buchholz (Dec 30, 2011)

Never bothered with foam board, mainly because I live in an apartment and didn't like the idea of bringing it here and cutting it. When I re-started my layout with a new piece of plywood back in 2011, I decided to use a roll of grass paper as my base, occasionally acquiring small chunks of foam I could bring home in a bag and shape out on my balcony. Needless to say, I've been more than happy with the results over the years.

-J.


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## Rook (Nov 5, 2017)

Cardboard panels is all I can come up with for alternative layout support. Modular, hollow with ribs for support. A place to hide circuit boards and wiring or just hang them under the panel with nylon wire ties. Just babbling here like usual. What did you mount the under track hardware to when using the grass mat? I like the idea for a basic groundcover. My balcony is the best place for dirty jobs and painting


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## CTValleyRR (Jul 26, 2014)

I don't think cardboard panels are a good option. They're sturdy in the direction of the ribs, but very flimsy otherwise, and they don't like liquids very much (many of our scenery products require diluted glues).

A 2x8 foam panel really is your best option.


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## Big Blue (Jan 25, 2017)

*First layout!*

Am just finished first layout this year. As am in apartment and didn’t want to cut foam board and wasn’t sure if I would make dcc work. Used 3/8 inch plywood with 1/2 inch camping floor matting over plywood. No mess and it’s firerated. So far working well.


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## sachsr1 (Mar 3, 2016)

Another good thing about foam is you can make small layout features off of your layout, and then add them later. I made a small pond on a 1'X1' piece of foam once it was done I just cut out a section of the layout foam and dropped it in.


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