# Subroadbed foam question



## domer94 (May 4, 2015)

so im building this attic layout now, and I have a bunch of plywood left from the remnants of my former basement layout. I really don't want to lug sheets of ply to the third level attic and try to get it through the attic stairs... which I would have to cut the 4 x 8 sheets in half anyhow. for this layout , I wont have to climb on for backdrops etc due to the roof pitch. is foam enough support? the spacing of my bench members is about 3'. will this be enough for foam to support the track and all?


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## Semper Vaporo (Jan 2, 2008)

How thick of foam are you planning on? I think no matter what thickness it will eventually sag between the supports, so I think you will need to put some plywood under it anyway, but maybe not as thick as if using only plywood. But then, the foam won't support someone leaning on it either. I suppose you could build some additional support between the main cross members, but why not use plywood... lots less work in the long run.


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## kormsen (Oct 27, 2009)

three foot is a long distance. that would call for 2" or thicker foam.

but you could cut some plywood stripes of 2 or 3" broad and glue them vertically below the foam.


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## Homo Habilis (Jul 29, 2011)

My railroad is in a basement with difficult access for 4x8 sheet goods and I was also concerned about the waste associated with the usual cookie-cutter method to create the sub-roadbed. I found the following video that looked promising: 




I ended up using the Masonite Spline Sub-Roadbed on an L-girder open grid and am quite please with the results. It was a bit time consuming since I only had enough clamps to do about 10 feet at a time though I only had 160 feet of track. I covered the splines with the Flexxbed product and it makes the wheel noise while running trains reasonably quiet.

Perhaps one of these methods will satisfy your needs.


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## domer94 (May 4, 2015)

well , I think I maybe just avoiding the inevitable.. im going to end up humping plywood up there. I figure I have enough of it already, plus the layout is pretty much one level with no grades due to the roof pitch. so I will end up cutting the 4x8 in lengthwise halfs and doing it that way. was just fishing for some alternative hope I guess! lol


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