Plywood, Cork and Track

[Mark5]

To put my experience in context, the plywood and homasote was only under where there was track. All other areas were "open" so that I could build up (or down) the scenery.

The HO switching thing I am building will be like that.

I am undecided about the next N layout though. I might try being a foamer. 

Mark

[OldEastRR]

Thin plywood, homasote, cork for track ROW and (w/o cork) industry foundations. Leaving open space everywhere else to use foam. Tracks need gradual grades and sitting on risers works well for this. All other areas can be of wildly varying slopes, cuts, material composition, etc, from steep roads coming down to a grade crossing to deep valleys under a trestle to long sloping river banks. Even towns aren't all level except in very flat terrain. Plywood/homasote works fine (and quietly) for those long grades and curves of track, but to easily carve all kinds of terrain both above and below track level I like foam. If you screw up an area, just cut it out and start with a new piece of foam.
Problem is,  Homasote has been replaced by foam sheets as the prime slab insulation in home construction, so it's hard to find.

[prr7161]

On the modules I built recently, I have Homasote over 1/2" plywood underneath the track and open grid elsewhere to be filled in with foam for scenery base.  The next module will be 1/16" cork over 3/4" plywood under the track.  There are surface imperfections in the Homasote, the worst of which I sanded out - for laying yard tracks on direct (not mains, which are on typical profiled cork) it's not too bad.  But it is messy to work with and has to be sealed up for moisture stability.  Over the winter as everything dried out I had issues with both the plywood and the Homasote curving and I had to go through a frustrating process of bracing everything from underneath to get it flattened out again.  Post-sealing, so far as the humidity has come up again, no problems.  But rather than court that problem again, I think the cork on thicker and higher grade plywood will be much more stable without increasing the overall thickness of the track support.  It'll also be similar from a sound deadening perspective - similar mass and isolation.

[DKS]

I am undecided about the next N layout though. I might try being a foamer. 

Once you go foam for track,
you never go back...

I made the switch in the mid-90s. Except for my micro-layouts (which are still foam, in their own way), I've always used foam. No regrets, and if I had a shot at a big home layout again, it would be foam.

Homasote? That's "dark ages" stuff to me.

[Bill H]

Thin plywood, homasote, cork for track ROW and (w/o cork) industry foundations. Leaving open space everywhere else to use foam. Tracks need gradual grades and sitting on risers works well for this. All other areas can be of wildly varying slopes, cuts, material composition, etc, from steep roads coming down to a grade crossing to deep valleys under a trestle to long sloping river banks. Even towns aren't all level except in very flat terrain. Plywood/homasote works fine (and quietly) for those long grades and curves of track, but to easily carve all kinds of terrain both above and below track level I like foam. If you screw up an area, just cut it out and start with a new piece of foam.
Problem is,  Homasote has been replaced by foam sheets as the prime slab insulation in home construction, so it's hard to find.

And the last place selling pre-cut homasote roadbed has closed down.

[mark.hinds]

Hi Folks:  IM planning a layout in N scale -- ive been watching the Canadian Canyons video series from Model Railroader, and I notice in that series, David Popp chose to put cork directly on the plywood and then track on the cork, Does this provide sufficient sound dampening, or should I try to put a layer of Homosate over it (worried about switch rod lengths etc at that point)

Your feedback appreciated!

TIM

I built my track and benchwork with cork on 1/2" plywood (1/4" on the helix), per the circa 1980 MR Clinchfield project layout.  It has always been reasonable WRT sound dampening.  However, I still have no ballast or scenery, and this may affect the final sound behavior.  So as others have suggested, do a test section, with ballast and scenery. 

[mcjaco]

To put my experience in context, the plywood and homasote was only under where there was track. All other areas were "open" so that I could build up (or down) the scenery.

The HO switching thing I am building will be like that.

I am undecided about the next N layout though. I might try being a foamer. 

Mark

My Father's HO layout was largely homasote. Used primarily for the towns where it was flat.  Everywhere else was L girders. 

I loved Homasote.  It was easy to spike down track and remove it should you run into issues.  I'd use it in a heartbeat again if I ever do my "dream layout" in my head.  I personally hate foam.  One layout, and a module, and it drove me crazy.  It's just as messy, it not messier than working with homasote.

They both have their place.