Hi all, 

I have a quick question regarding benchwork: 

When the actual benchwork is finished, is the homasote typically applied directly on top of the benchwork, or is plywood used as a layer beneath the homasote? 

 

Best,

Jacob 

Original Post

Hi Jacob - most people put the Homosote on top of the plywood. Depending on the span of support underneath, my experience with Homosote caused some warping.

I recommend a layer of 1-inch thick extruded pink foam glued to the top of the plywood. This allows you to introduce terrain contours lower than the level of the track, which is realistic. In the real world, is there never any terrain beneath the level of the track? For more realism, you could stack pink foam in several layers or use thicker pieces, as I have done on my layout. The track sits on several layers of pink foam and is five inches above the level of the water in the creek. The hill is also made from layers of pink foam but is entirely above track level and can simply be lifted off the layout if necessary. There is an access door for track cleaning behind the Ophir Depot (atop the hill) although I also do that partially from either end of the tunnel.

MELGAR

MELGAR_2019_0322_24_NORTH_END_6E

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Last edited by MELGAR

Jacob,

Homasote has little or no structural strength and must be supported by something.  I use 3/4" plywood as the sub roadbed and Homasote as the roadbed.

Best of luck.

Ed

Gentlemen,

I’m in the planning stage and I’ve been pondering this issue. What Melgar mentioned has helped me to achieve clarity. What could be used for the roadbed on top of the foam?

Thank you 

@MELGAR posted:

I recommend a layer of 1-inch thick extruded pink foam glued to the top of the plywood. This allows you to introduce terrain contours lower than the level of the track, which is realistic. In the real world, is there never any terrain beneath the level of the track? For more realism, you could stack pink foam in several layers or use thicker pieces, as I have done on my layout. The track sits on several layers of pink foam and is five inches above the level of the water in the creek. The hill is also made from pink foam but is entirely above track level.

MELGAR

MELGAR_2019_0322_24_NORTH_END_6E

Melgar - how did you attach the track to the foam?
Joe

I can't speak for any one else but I attached my track to the foam on my layout with a hot glue gun set at the low temperature setting.

Ray

@jhend1000 posted:

Hi all, 

I have a quick question regarding benchwork: 

When the actual benchwork is finished, is the homasote typically applied directly on top of the benchwork, or is plywood used as a layer beneath the homasote? 

 

Best,

Jacob 

Jacob - If you plan on using homasote (it is good for sound proofing, takes screws, paint and glue), and you plan on getting on top of the layout for any reason you need a plywood under the homasote. The homasote will not support your weight. If you screw the plywood to the bench work then screw the homasote to the plywood you should be okay as far as warp is concerned. Using the pink foam is another good idea which I did for elevated track but I had to glue the track down to the foam which is kind of permanent.  I just asked Melgar how he attaches his track to foam.
I am moving soon so will be building a new layout. I want to place a river in the back of the layout so am contemplating building that section of the bench work 4 inches lower than the rest of the bench work. I will cover that section in plywood then build up foam contoured to the river design so it is even with the rest of the bench work. In this section I plan on gluing the track down unless Melgar has a better solution. The remainder of the layout will be plywood / homasote.
Joe

I'm not sure how Melgar did it but all you need to do to keep track in place on foam (or any other material) is to ballast it and then glue the ballast.  That holds the track in place just fine unless you are building modules or a layout which will travel.  

-Greg

Sorry, I didn't see the question until a while after it was posted.

I use cork roadbed beneath the track. In this case, I attached it to the pink foam with a mixture of a bit of two-part epoxy with mostly Titebond II Carpenters Wood Glue (available at HD). I mark the track center line onto the foam as accurately as possible and then use weights to hold the cork in position for a day or so until the glue dries. The bond between the cork and the pink foam is very strong. I also use Atlas O track screws. It seems that the cork holds them quite well without any type of glue.

MELGAR

Last edited by MELGAR

Unsupported homosote will warp in my opinion.    I think it absorbs moisture and then sags between braces.    I built a layout with just homosote on the braces/risers and after about a  year I have very noticeable dips in the homosote between the wood braces.

You're certainly correct. just by sitting a sheet of Homasote across a couple of supports with several feet between them, it won't take long to see a sag.  Solution:  Don't do that.

Unsupported foam will also eventually sag. Don't ask me how I know this... I highly recommend 1/2" plywood underneath for support. I DO embrace the idea of supported foam  to allow scenery below track level.

Chris

LVHR

To fasten Atlas track to foam I used carpet tape. Works great. Some places I still have it that way 3 years later as I am slowly ballasting all my track. The ballast makes it look really good. DO NOT put tape under switches.

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