Where to put Homasote (or any sound deadening material)

@Brad Lipman 120618 posted:

I know that most people put the homasote board between the layout plywood and the tracks.  Has anyone tried putting the homasote under the layout plywood?

Absolutely NOT!

Would that be enough to deaden some of the train noise vibrations?

No, not at all!

Thanks for your comments.

you want the track separated by the Homasote which deadens the sound otherwise the plywood will act like a sounding board and echo the train running noise on the plywood directly!

Alan

Truthfully, knowing what the Homasote is supposed to accomplish, that thought never even occurred to me. 

IF the plywood were vibrating like a drum, putting the homosote underneath would stop or reduce the vibration and therefore reduce the sound I think.     I don't think it would as affective as putting it between the track and the plywood.

Now here are some thoughts on this.   If you screw the track through the homosote to the plywood, won't that transmit some of the sound through the homosote also?     A second point that I have actually witnessed:    If you lay ballast and glue it down well, it becomes a hard solid surface and if it goes beyond the homosote and connects to the plywood, it will conduct the noise vibrations down to the plywood to some extent also.

On the other hand, part of the fun of running the trains, is hearing the sounds of the wheels pounding the rail and hitting the joints.

As an alternative consider NOT building your layout on inexpensive plywood. My layout is small so I chose 3/4 in thick laminated maple that I got at Lowe's and had them cut it for me. It is heavy and naturally flat without warp. The top and bottom surfaces are smooth and easy to work with for whatever scenery you may want to add. My layout is Atlas track on cork roadbed on the maple. I staple the roadbed and use track screws for the track. The sound is IMO fantastic. It amplifies the "heavy" sounds that go with a big train pulling a consist. I kind of think of it the way wooden musical instruments are made. I love listening to the overall effect.

If I had a bigger layout I would do the same thing. To me, the idea of a cheap plywood plus homosote composite sounds difficult to work with and inconsistent with respect to sound results. And if you use Fastrack you have the additional step of trying to cram foam under the track. Ugh. No thanks. Do yourself a favor and at least go look at Maple laminate at Lowes or Home Depot. It's more expensive than plywood and heavier, but worth the effort.

@prrjim posted:

IF the plywood were vibrating like a drum, putting the homosote underneath would stop or reduce the vibration and therefore reduce the sound I think.     I don't think it would as affective as putting it between the track and the plywood.

Now here are some thoughts on this.   If you screw the track through the homosote to the plywood, won't that transmit some of the sound through the homosote also?     A second point that I have actually witnessed:    If you lay ballast and glue it down well, it becomes a hard solid surface and if it goes beyond the homosote and connects to the plywood, it will conduct the noise vibrations down to the plywood to some extent also.

On the other hand, part of the fun of running the trains, is hearing the sounds of the wheels pounding the rail and hitting the joints.

Well, in theory you are correct: in vehicles, self-sticking rubbery sound deadening material is applied to interior sheet metal expanses to keep them from acting like a speaker cone, but homosote *between* track and plywood does a much better job of keeping the vibration away from the plywood *before* it can act as a sounding board, *and* it adds mass bonded to the plywood, an effect that also reduces the sound.

As to your other questions: yes, nailing through to the plywood would reduce the sound isolation, which is why I only use nails long enough to go through the ties, the foam track roadbed and into the foam board (which I use instead of homosote), with no nail-to-plywood contact. And, yes, if you just use a narrow width of homosote and glue ballast down between the track and plywood, I suspect you might get *some* sound leakage . . . so I suggest you just don't do that! Most who use homosote or foam board completely cover the plywood, so that can never be an issue (I used stone ballast glued down over foam roadbed to the foam board top layer, and did not notice any change in sound suppression effectiveness).

And yes, toy trains *should* be a bit noisy -- the kids especially love it! -- but there can be too much of a good thing, so some thought to sound suppression is IMHO, err, *sound*!

@prrjim posted:

Now here are some thoughts on this.   If you screw the track through the homosote to the plywood, won't that transmit some of the sound through the homosote also?   

My track screws don't go through the Homasote into the plywood for that very reason.

What has worked well for me on two layouts is homasote glued to plywood with wood glue and no screws.  I then use adhesive caulk to attach cork roadbed to the homasote.  I use nails or track spikes to attach the track to the cork and they are long enough to go through the cork and into the homasote but not the plywood.

In addition to the above, Homasote is much easier to spike/screw  into. 

Mitch

In my experience homasote with cork roadbed is the best option for toy trains. The platform itself doesn’t matter as long as it rigid and strong enough to hold the trains

I used Homasote roadbed from California Roadbed (no longer in business, I think) glued to the 3/4" plywood sub-roadbed, with code 148 2-rail Micro Engineering track also glued to the Homaosote with Weldbond adhesive. The addition of ballast secured with diluted white glue holds the track in place very well despite the engineering-plastic ties. The benchwork is solid, heavy and rigid and the trains run quietly.

On our layout, we used 1/2inch MDF for the table top and glued 1/2inch pink foam , then painted before attaching the track using 3/4 inch screws through the rail ties. The screws just made it into the MDF, and holds the track in place.  There is some noise but it is acceptable for still having a conversation while the trains are running. See attached.

Brad,  several years ago I had the same thought. So I glued sheets of foam insulation to the bottom of the plywood table.  It did not help with the sound from the fastrack.
About 5 years ago I got some used Homasote and it was painted green semigloss on one side.  I put the green side up and I think the semigloss reflected the sound back into the room.  A couple years later I flipped the Homasote over and there was a significant difference in the sound level, much lower.

I have since laid indoor/outdoor carpet from Lowe’s over the Homasote to help hold the sound down from fastrack.

Doug