Sub-roadbed materials

[tomikawaTT]

You might want to talk to a siding contractor who installs sheet siding (steel, aluminum or vinyl) about fan-fold underlayment.  It's thin foam, 4' x 50' folded up into a 2' x 4' bundle.  I'm using mine for roadbed, since cork doesn't like single-digit humidity.

My track, from the bottom up:

• Cookie-cut plywood, 1/2 inch or thinner (shimmed as necessary at splices for a smooth top.)  If it tries to warp or twist I beat it into submission by screwing steel angle stock to the underside.
• Fan-fold underlayment roadbed, attached with white or clear latex caulk.
• Cardstock template, exactly as wide as the tie-ends of whatever is above it.  One layer (minimum) or as many as necessary to keep the tie tops (or railheads) at the same level, secured to the roadbed with brown paintable latex caulk.
• Cardstock shims (if used) secured with grey latex caulk.
• Flex track, or wood ties for hand-laid specialwork, secured with grey latex caulk.  I use track nails to position the flex until the caulk sets, and spike raw rail to the wood ties for specialwork.  (Once the caulk sets, the track nails can be removed or just left in place.)

I've been using this system for three years now, and am completely satisfied with it.

Chuck (modeling Central Japan in September, 1964 - in a Mojave Desert garage)

[L Cowan]

Try calling an insulation contractor in your area an d ask about foam board, even in warmer clims it would be used because of air conditioning.

Hope you find it as it is a great material to work with.

Lee

[joe-daddy]

3/4"  Plywood with cork, homasote or soundboard on top of that.

my comments on my blog

 http://wwwjoe-daddy.blogspot.com/2007/01/roadbed.html

 

my 2 cents.

 

Joe Daddy 

[ndbprr]

OSB is better tha particle board because particle board will sag with time.  I would see if you could return it.  If you didn't keep the receipt they should give you s tore credit for it.

[E-L man tom]

Yes, plywood works the best, 1/2 inch; you can get by on 3/8" CDX on smaller layouts like mine, which is a small, L shaped shelf-style switching layout (9 ft. along one wall with 5 ft. of staging and 1 ft wide). I do, however, think that the better the grade of plywood the better the results and the easier it is to work with. That particle or chip board is just too inflexible and too rough of a surface to work with. The only advantage to working with chip board is that it is not as prone to warping as plywood is. 

[ChrisNH]

The home depot here only caries the white styrofoam sheets.

 My Home Depot and Lowes both carry it.. but I live in New Hampshire. Maybe they are not because you live in a warm area I am guessing? Perhaps they can order it.

Chris 

[Anonymous]

Ok, Yeah I was wrong. I have a sheet of "particle board" or "Chipboard".

Photo from wikipedia

 

Mine looks like the one on top.

A comparison shot of the two:

 The evil board I mentioned in the last post is OSB (Orient strand board)

 

[Anonymous]

I think I may have been wrong about the MDF desegantion I gave the wood earlier. As I recall MDF is very smooth on both sides, and kinda paper-like inside. 

I suspect that the chip board that you used may be the same stuff as i'm thinking of using, but maybe not. The board I have looks like what would happen if you mixed sawdust and glue into a paste and then extruded it into a 4x8 sheet and let it dry. The only other boart that I might call chip board is the cheap stuff that they use for sub-floors that is large chunks of wood glewd haphazardly together and plained flat. I hate that stuff and won't touch it!

[BNENGR]

Hello Justin,

I have used what I call "chip board" (can't think of the real name -CDX?) 5/8" thick in 4x8 sheets for parts of my layout and also 1/2" & 5/8" plywood (smooth on both sides, one side better) for the "cookie cutter" parts of the layout. They both worked well for me. Then I used cork roadbed and sheet cork for the track. I used all ''L-girder" construction for the base using 1x2's, 1x3's, 1x4's and 2x4's. You could drive a Mack truck on it.

Good luck!

Paul

[Anonymous]

I once again have bought something without readig first... one of these days i will have to learn to stop doing that. Anyways, My original plan was to just throw a 4x8 sheet onto some framing, cover the whole thing in foam and carve out the scenery from there. I went to the store, picked up some 2x2, some 1x2, and a 1/2"x4'x8' sheet of MDF. I figured the MDF would make a good base because it is sturdy, not to heavy, and a lot smother than the cheaper plywood that home depot has. I really didn't want to pay like $40 a sheet for the hardwood stuff either.

Here I ran into a problem. The home depot here only caries the white styrofoam sheets. (The kind that break into tiny staticly charged beads and go everywhere) I asked them if they carried the pink or blue extruded foam and they looked at me like I was crazy. Same thing at lowes. I wasn't just asking the floor monkies either, I went over to contractor services and asked there. The local lumber yards yeilded either the wrong foam again or no insulation whatsoever.

 

Fast forward to today where I have read through like 20 pages of the construction fourum, and 2 books including the "how to build benchwork" book in the model railroader series. It  has become very clear to me that an L girder setup using the cookie cutter method is going to serve me best. I am wondering now though if the MDF which I purchaced will still work, or if I'm compleatly hosed. It does bend a bit, and might work, but i'm not sure if i'll be able to use it.  I had considered leaving chunks of it for the yard and town areas, and then cutting the sub-roadbed from normal plywood, but this almost seems like more work than it's worth. 

At this point, if I can't use the MDF then i'll probably just scrap it and get a sheet of 1/2" ply to do the whole thing. I know that MDF hates water, so plaster wouldn't be kind to it, but I may be able to paint it to seal it first? It's not that big of a deal if i can't use it. It was only like $15 anyways.

 Thanks, 

Justin