Foam roadbed?

[MichaelWinicki]

In regard to the comments about not having trouble with Woodland Scenics foam roadbed, all I can say is that I made a 1' long test strip of track and ballasted it. I managed to bump it, and sure enough the ballast cracked. Just sayin'


Hmm... I think my 600
pound gorilla friend may
have stepped on it...

Well if you're ever in western NY state... You're invited to come bump my layout. lol

[peteski]

I've used the WS foam roadbed and I think the squishing issue is overstated. 

We obviously have 2 camps in this WS foam roadbed.  It really doesn't take much pressure to deflect that roadbed.  Like I mentioned in my earlier post, the type of ballast adhesive an the amount used might be in play here.  If the the adhesive is flexible and ample amount is used it might flex with the roadbed and remain intact.   If the adhesive is brittle and very little is used, it might crumble when the roadbed deflects under pressure.

[Dave V]

Foam roadbed is very easy to work with.  However, I don't plan to ever use it again because I found it wouldn't hold superelevation in curves.  I also found when I built Enola Yard that my yard tracks had vertical deflections...perfect for a Penn Central/early Conrail layout but less so for Pennsy in its heyday.

[nuno81291]

Never had a problem with the WS stuff. So much so I have no need to go to cork (nor is cork more available per some opinions here).

[Mark W]

...the type of ballast adhesive an the amount used might be in play here...

Yes; type of adhesive, type of ballast, and application method all play a much bigger variable than type of roadbed.

Woodland Scenic ballast (the crushed walnut shells) are much more flexible and forgiving than real rock ballast.  Likewise, walnut is much more absorbent than rock.  Misting with the same amount of water/glue mix will seep further into WS Ballast than AR&M Ballast.   

If you're using rock ballast, you'll need to apply more water/glue mix than otherwise to fully saturate and glue the entire ballast profile.  If done properly (with properly sized ballast), the ballast itself will hold up under pressure, making type of roadbed practically an irrelevant variable.

[Loren Perry]

Foam roadbed is very easy to work with.  However, I don't plan to ever use it again because I found it wouldn't hold superelevation in curves.  I also found when I built Enola Yard that my yard tracks had vertical deflections...perfect for a Penn Central/early Conrail layout but less so for Pennsy in its heyday.

I have installed superelevation on all my double track mainline curves that are equipped with WS foam roadbed. To do this, I added thin styrene shims between the outer ends of the ties and the top of the roadbed and than ballasted using white glue as an adhesive. That was eight years ago. Today, the superelevation is exactly as it was when new and my trains run through them with no wobbling or dipping. In my earliest articles on building a "Steam Friendly Layout" for N-Scale magazine, I used photographs to illustrate the steps I employed in laying my track.

One of the ways I tested my track's precision was to run a train of Kato Amtrak Superliners through the curves and observe the deflection of one car's end against that of the adjoining car. This technique quickly pinpointed areas where the superelevation, vertical displacement, or curve radius was not uniform and I was able to make corrections before ballasting. After I tuned up the track so the Superliners could negotiate the curves without any twitching, the rest of my trains would be guaranteed a very smooth run. Today, I can run any of my passenger trains through these superelevated curves (which also include easements at each end) and the visual effect is that of a single long and flexible unit rather than a series of individual cars bobbling about.

I suspect that those having problems with ballast failures when using WS foam trackbed are being waylaid by a too-thin or otherwise inadequate application of ballast adhesive. I used ordinary Elmer's white glue thinned about 50/50 with water and a few drops of dishwashing detergent to allow the glue to permeate all around the ballast granules. I also suspect that some of those having problems are applying far too much physical force to the finished track, causing it to deflect downward, much like when airplane manufacturers set aside an early example of a new airframe so they can test it to destruction. There is no logical reason for this, even when cleaning track. When using a Brite Boy, I apply just enough force to make good contact with the railhead and no more. Only a few ounces of force is needed. Anything else is unnecessarily destructive. The scrubbing action of the Brite Boy pad will do the job. Liquid track cleaners need about the same amount of force as the solvents in them will do the hard work for you.

N-scale track, like the models that ride on them, do not benefit from excessive force being applied to them by 1 to 1 scale humans. Save that type of rough handling for HO scale and larger. Woodland Scenics' foam roadbed, when used properly and carefully, will yield a very smooth and quiet-running track system that will last for years. This is from my personal hands-on experience.

[Dave V]

I have installed superelevation on all my double track mainline curves that are equipped with WS foam roadbed. To do this, I added thin styrene shims between the outer ends of the ties and the top of the roadbed and than ballasted using white glue as an adhesive. That was eight years ago. Today, the superelevation is exactly as it was when new and my trains run through them with no wobbling or dipping. In my earliest articles on building a "Steam Friendly Layout" for N-Scale magazine, I used photographs to illustrate the steps I employed in laying my track.

One of the ways I tested my track's precision was to run a train of Kato Amtrak Superliners through the curves and observe the deflection of one car's end against that of the adjoining car. This technique quickly pinpointed areas where the superelevation, vertical displacement, or curve radius was not uniform and I was able to make corrections before ballasting. After I tuned up the track so the Superliners could negotiate the curves without any twitching, the rest of my trains would be guaranteed a very smooth run. Today, I can run any of my passenger trains through these superelevated curves (which also include easements at each end) and the visual effect is that of a single long and flexible unit rather than a series of individual cars bobbling about.

I suspect that those having problems with ballast failures when using WS foam trackbed are being waylaid by a too-thin or otherwise inadequate application of ballast adhesive. I used ordinary Elmer's white glue thinned about 50/50 with water and a few drops of dishwashing detergent to allow the glue to permeate all around the ballast granules. I also suspect that some of those having problems are applying far too much physical force to the finished track, causing it to deflect downward, much like when airplane manufacturers set aside an early example of a new airframe so they can test it to destruction. There is no logical reason for this, even when cleaning track. When using a Brite Boy, I apply just enough force to make good contact with the railhead and no more. Only a few ounces of force is needed. Anything else is unnecessarily destructive. The scrubbing action of the Brite Boy pad will do the job. Liquid track cleaners need about the same amount of force as the solvents in them will do the hard work for you.

N-scale track, like the models that ride on them, do not benefit from excessive force being applied to them by 1 to 1 scale humans. Save that type of rough handling for HO scale and larger. Woodland Scenics' foam roadbed, when used properly and carefully, will yield a very smooth and quiet-running track system that will last for years. This is from my personal hands-on experience.

I used the same technique you did.

[randgust]

There's another one out there - the two-sided sticky stuff that almost looks like a roll of roofing tar.     I had a friend that did an entire room layout in the stuff in the 70's.  It dried out, shrank, and had the darndest property ever that if you laid it around curves, it stretched to the outside, compressed to the inside, and produced reverse superelevation.

I still do subroadbed out of plywood, but put either a 3/4 x 3/4 pine strip glued between risers under it, or on my T-trak modules, a vertical 2" section under the track centerline from end-to-end to introduce more surface rigidity.   

I'm still a cork guy at least on the mains, glue it down to painted/primed plywood with waterproof glue, drill through the ties and use small nails, paint the track, ballast, then pull the nails.   Some sections are still going after, hmmm... 34 years.  My first portable module, the Hickory Valley, was dropped down a flight of stairs once.    No real damage to speak of either. 

[MichaelWinicki]

If you're using rock ballast, you'll need to apply more water/glue mix than otherwise to fully saturate and glue the entire ballast profile.  If done properly (with properly sized ballast), the ballast itself will hold up under pressure, making type of roadbed practically an irrelevant variable.

I think there's a lot of truth in that.

Inadequate gluing probably has a lot to do with it.  I admit I saturated the bejesus out of mine–I used Highball rock ballast.  The term "protective shell" is used in describing a variety of products... But in this case it's an apt description.

A couple times I've had to replace or remove track/ballast/roadbed, I pretty much had to hit the ballast fairly aggressively in order to get it to crack/break.    In other instances where I've needed to drill holes next to the track, through the ballast & roadbed, there's been no crumbling of the ballast in all directions from the drill hole– both the ballast and the roadbed held up well. 

[peteski]

SO we have pretty much estalished that vell-glued ballast is the key to preventing crumbling when using WS ballast.

But I thought that the main reason for using very soft roadbed (WS) was to dampen the noise generated by the train.  But if we place a very hard shell of ballast/glue over that soft roadbed, that will physically connect the ties and the sub-roadbed together. The vibration of the passing train will be then transmitted directly to the sub-roadbed and to the layout. What is then the advantage of that extra soft roadbed over the old-fashon cork?

[Mark W]

What is then the advantage of that extra soft roadbed over the old-fashon cork?

In my experience, there is no advantage/disadvantage* in this case.  It's all just marketing.

[Edit] *Once properly ballasted.

[MichaelWinicki]

In my experience, there is no advantage/disadvantage* in this case.  It's all just marketing.

[Edit] *Once properly ballasted.

I do not have cork on my layout so I can't offer that comparison, but in spots where the track was laid directly on the 1" pink Styrofoam, the noise of a passing train is considerably louder than when traveling on the WS foam roadbed– So even after being ballasted and glued there is still noise reduction to be had.

[R L Smith]

I've used the WS roadbed on the last two layouts with no issues.

I also use Styrofoam  on plywood as a base, but I have successfully used two 1" layers glued together over a lattice-style framework.  The top layer is cut cookie-cutter style to allow for a smooth flat surface for scenic waterways below track level.

I am definitely going to consider trying the steel structure under foam the next time around!

Ron

[Chris7092]

Thanks to everyone for your comments.  I am just about to begin building my first layout, and the info supplied has been valuable.  I am leaning toward a simple plywood sub-roadbed (1/2 inch most likely).  I would love to hear recommendations for the type of wood to use.  The layout will be 17' long and 6' wide, essentially an elongated oval with each side of the layout being 2' deep with 2' in between each side of the layout.  Imagine seeing an N-trak layout with those dimensions and you'll see what I'm aiming for.

My plan at this point is to cut the plywood into 2' x 4' modules and framing each one of the modules with 1x4" wood boards.  Then, screwing or bolting each section together.

I do live in a hot and humid environment (northern Georgia), and the layout will be built in my basement which also serves as a third car garage, so temperature fluctuations and humidity will be a factor.  Any advice or experience handling this type of environment?

Thanks in advance for the advice,

Chris
Ringgold, GA

[robert3985]

Thanks to everyone for your comments.  I am just about to begin building my first layout, and the info supplied has been valuable.  I am leaning toward a simple plywood sub-roadbed (1/2 inch most likely).  I would love to hear recommendations for the type of wood to use.  The layout will be 17' long and 6' wide, essentially an elongated oval with each side of the layout being 2' deep with 2' in between each side of the layout.  Imagine seeing an N-trak layout with those dimensions and you'll see what I'm aiming for.

My plan at this point is to cut the plywood into 2' x 4' modules and framing each one of the modules with 1x4" wood boards.  Then, screwing or bolting each section together.

I do live in a hot and humid environment (northern Georgia), and the layout will be built in my basement which also serves as a third car garage, so temperature fluctuations and humidity will be a factor.  Any advice or experience handling this type of environment?

Thanks in advance for the advice,

Chris
Ringgold, GA

Chris, for your hot, humid environment, I'd stick with an exterior grade plywood that has an "X" as its last designating letter.  Since you'll be using it for subroadbed, it's important that you have a quality surface on which to mount your roadbed, and although CDX plywood is very common (the C & D stand for the quality of finish on either side of the plywood, D being the worst grade, and C being just a tick better) I'd opt for more expensive, but better grade BDX, or ADX if you can find it, or even AAX or BBX, with at least one side finished pretty nicely.

I'd also make all of your benchwork from exterior grade plywood, making sure to glue and screw all of your joints using a quality yellow carpenter's glue. 

After I was done with the benchwork, but hadn't installed my subroadbed yet, I'd seal everything...install the subroadbed, sand the surface you're going to mount your roadbed on and seal it too.

OR, you could construct your benchwork (with the exception of risers and subroadbed) from steel, which may be simpler, stronger. lighter and easier to work with than wood.  You certainly would NOT have expansion/contraction/warpage problems with steel.  Just use the best construction protocols for it making sure the joinery is stable.

I'd probably also paint your benchwork too before installing subroadbed...even the steel as steel rusts.

Remember to sand both the surface you mount your roadbed to on your subroadbed, and sand the top of your roadbed (if you use cork) before laying track.  This goes a long way towards giving you trouble-free rails to run on.

Cheerio!
Bob Gilmore