# Foam on top of Plywood...what thickness



## wesleyb420 (Jun 13, 2012)

Hello everyone, I have built a table that is 5x12 and was wondering about the foam thickness for the top. I have a 1/2" plywood base and plan on a double main oval with switching on the inside. Since i wont be getting into heavy grading or crazy scenery, would 1/2" or 3/4" foam work or 2"? I am running Kato track and modern diesels and this will be my first "real" layout so i don't plan on getting too crazy with the setup. I welcome any input and please let me know if i am being too vague.

Thanks in advance!


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## wvgca (Jan 21, 2013)

basically i depends on how 'deep' you might want to cut some scenery / terrain ...if you want a few gullies or inch and half deep rivers, then 2" ... if all you have in mind is some ditches along side the track in places, 1/2" would be fine...


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## raleets (Jan 2, 2011)

My 10'X10' layout is on a 5/8" plywood base with 1" foam on top. It's worked out very well. 
Good luck,
Bob


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## fcwilt (Sep 27, 2013)

1/2" AC plywood with 2" foam.


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## CTValleyRR (Jul 26, 2014)

Sounds like a lot of this stuff is overbuilt. The foam is plenty strong enough by itself with stringers on 18" centers or less.

Since you already have a plywood base, you don't really need foam. It only provides relief to the terrain, which you can also achieve just by elevating the track, either on foam or wood risers. How much you raise it depends on how much relief you want to have.


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## wesleyb420 (Jun 13, 2012)

This will be hanging from the ceiling in my garage...it should be overbuilt. I'm not really sure how you can to that conclusion of mine being overbuilt from the description I gave, but ok.

I have taken it apart to glue and went with the plywood with the 2" foam. Thanks everyone. I'll post pics in the next few days.


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## CTValleyRR (Jul 26, 2014)

wesleyb420 said:


> This will be hanging from the ceiling in my garage...it should be overbuilt. I'm not really sure how you can to that conclusion of mine being overbuilt from the description I gave, but ok.
> 
> I have taken it apart to glue and went with the plywood with the 2" foam. Thanks everyone. I'll post pics in the next few days.


I wasn't necessarily referring to your layout, but to the general trend of using foam and plywood, for most applications, it is overkill. Not wrong, just not necessary. It comes from people not realizing how sturdy the foam panels are (my youngest, when he was 7 years old and about 50 pounds, actually sat on a piece of the 2" stuff between two sawhorses about 4' apart). And yes, for your application, unless you're planning to be whacking it with things, I would have built as lightly as possible: a wood frame, stringers on 16" centers, and foam. No plywood.


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## fcwilt (Sep 27, 2013)

The plywood is what I fasten all of the electronic and mechanical devices to.


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## deanathpc (Mar 29, 2015)

My biggest question now is under table switch machines. 1" is the max thickness without using longer wire to reach the track. So how is everyone doing this? Or are tortoise motors not the thing these days?


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## fcwilt (Sep 27, 2013)

deanathpc said:


> My biggest question now is under table switch machines. 1" is the max thickness without using longer wire to reach the track. So how is everyone doing this? Or are tortoise motors not the thing these days?


I use 2" foam over 1/2" plywood with Tortoise motors. 

I just replace the wire with a slightly thicker one. You do have to enlarge the hole in the Tortoise a little.


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## deanathpc (Mar 29, 2015)

fcwilt said:


> I use 2" foam over 1/2" plywood with Tortoise motors.
> 
> I just replace the wire with a slightly thicker one. You do have to enlarge the hole in the Tortoise a little.


Where does one get this wire? What thickness are you using? 

Does anyone not use plywood and only foam as the base while still using under table devices?


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## fcwilt (Sep 27, 2013)

deanathpc said:


> Where does one get this wire? What thickness are you using?
> 
> Does anyone not use plywood and only foam as the base while still using under table devices?


As I was computer automating my layout I knew I was going to have lots of electronics underneath. The plywood provided a mounting surface.

Foam is not very strong and needs some kind of support, either plywood or framing.

I got my wire from Amazon. If you buy such wire get the straight pieces not the coils.


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## deanathpc (Mar 29, 2015)

What was the thickness or size of wire? Assuming it is still spring wire?


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## fcwilt (Sep 27, 2013)

I used 0.032" 

I got it from Amazon.

This was the part number: SMW-032-36-25


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## deanathpc (Mar 29, 2015)

fcwilt said:


> I used 0.032"
> 
> I got it from Amazon.
> 
> This was the part number: SMW-032-36-25


Ok thanks. I've been debating on foam etc but was worried about the thickness etc. Now I'll have to figure out what foam to do now. Lol. Hope this helps others too!


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