Sound Deadening Material

There are several threads on this topic so search for Quiet Brace or Homasote.

Quiet Brace or Homasote. I just used quiet brace and am happy with it, especially the fact that it's a lot less expensive. The noise level was considerably different between what I used before 1" foam on top of OSB.

Both are good products and widely used, apparently depending on your location.

Larry

Thanks Larry! This helps and I will use the quiet brace material.... Appreciate your help

Chas 

Hay Chas

Just a suggestion, I would paint it with a a cheap latex paint what ever color your base ground cover will be. It is nasty to work with. Sort of like getting tar all over you.

Larry

To  Collector65,

I'm just starting my first layout and decided on QuietBrace for all the reasons mentioned above.

Good advice above to paint it first.  I'm in the process of laying the 8 x4 sheets down (I need 20), and before I paint them I'm going to use a roll of masking tape to tape off the seams.  If you use more than one peice, do that before painting.  I'm not going to glue, nail, or screw the QuietBrace down because it is so tacky from the tar covering, I beleive it will stay put without securing it, plus if you nail or screw it to the wood table, you will transfer all the noise from the trains to the table.

One other reason to use QuietBrace is that I did an experiment with it.  I placed the cork roadbed on it - then my Atlas O track on it - then screwed the track down with the black screws Atlas sells and the screws were just the right size and stopped just before they got to the table top.  Also I tried to pull the track away from the QuietBrace with my hands, and as hard as I tried, I could not.

Have Fun

Corvettte

When I brought 20 sheets back from Home Depot and put them in my garage, everytime I went into the garage for about 6 days it smelled like oil.  Then I noticed the smell went away.  Now after about 10 days, it smells no more.  

As far as it being flammable, take a look at my attachment.  I got this information off of the Internet.

Corvettte

Screwing the Homasote or quietbrace to the plywood table top does not transmit track noise. ThHomasote ABSORBS the noise, leaving nothing to transmit. Sort of loke nailing a sponge to a table. Nothing you do to vibrate the sponge will affect transmission unless you actually hit the nail.

Homosote is good and provides a surface to work with. But, this is 2013. You can use the underlayment for laminate flooring. It is closed cell foam , 2mm thick, and has an STC of 67-74 compared to 56 for homosote. Sandwiched between two pieces of plywood is more effective. The sandwich is used in construction (by code) for upper flooring to reduce the noise transmitted to the lower floors.

Like a 1/2" plywood, 2mm floor underlayment, 7mm wooden floor under layment for the top.

I've attached some manufacturer brochures for your review. You decide. They all work.

Then... there's build the plywood deck and use premade cork roadbed. Cork is a very effective sound absorber and the method is tried and true. STC ~65. Cork is one of the more expensive materials, but you are only putting it under the track.

Moonman,

I like your suggestion but am a little confused on the "sandwich" order and materials.

!/2 inch plywood 2mm underlayment then plywood or 7mm underlayment.

Thanks!

Dave

I think he was referring to the order in which contractors use the material, I used this material when I put in laminate wood flooring in my old house.  You have the subfloor, which is usually plywood, then you put the foam/sound deadening material down, then the flooring.  In our case(s) it would be plywood, then foam, then cork roadbed, then track.

Again, I think this is what was meant.

Darren

I think Moonman's idea is good, but a bit of overkill.

For our purpose of cutting down on "some" of the noise, either Homasote (very expensive), or QuietBrace (very cheap) will do the job.

Corvettte

Moonman's suggestion of using flooring foam underlayment is intriguing... But several questions come up.

How would the foam underlayment be secured/glued to the plywood layout top? The brochure shows the material including a plastic vapor barrier on the underside. How is this material secured when working on a floor?

With the flooring method of layering both the foam and the wood top are not very thick (about 1/4"), so then how would the flooring be secured to the foam and then the track secured to the wood? Screws? Obviously, any screws used would need to be short and not go through the foam and into the plywood base. Glue? Could the wood top be glued to the foam and then the track glued to the wood and everything be secure enough for years of operation?

I like the idea of a sandwich layout top with modern sound deadening foam, but the thinness of the materials becomes a little problematic.

Has anybody actually constructed a layout using this foam floor underlayment technique?

Bert

I have used so many different materials on layouts that I learned that the best bang for the buck is Homosote, strong, easy to work with and deadens sound well.  This would be my choice.

Sorry I didn't get back in on this. The grandchildren arrived for an overnight. Minor bedlam.

Yep. Any adhesive would work. Yes to the short screws also. The floor underlayment is layered to hold fasteners well. Cost? Here in S. Jersey a 4 x 8 1/2" birch is around $45, I pay $30 for 100 sq. ft. of the foam at a flooring distributor and the 4 x 8 underlayment is $15. So $75 for a 4 x 8 sandwich.

!/2" birch 4 x 8 $45, 4 x 8 Homosote $27 +$72 and it weighs a ton.

The weight of the homosote deterred me from using it. If I were to build a permanent layout, I really like the cork road bed only and just scenic the plywood everywhere else. A 100% homosote is not really needed. The track roadbed is what needs to be sound absorbing material.

I am building portable modules, so weight is a big concern. The temporary holiday layout that I am building will have the sound foam with white felt on top for snow. That will be my test to compare it to homosote and the ability to hold a normal volume conversation with the trains running. If the results are positive, I will use it for the modules.

My target for my modules is March\April.

The sound experts use the same closed-cell, cross-linked foam in greater thicknesses. 4mm in airplane passenger areas, custom cars, etc. I was intrigued by it's light weight and performance and looked for an everyday product.

As I said before, it all works, as others have attested from experience. Use what's available locally at a cost that works for you.

Doesn't 45+30+15 still =90?

Word problem time. Let's see... If DoubleDaz has 100sq. ft. of sound material that costs him $30 and he uses 32 sq. ft. to cover a 4 x 8 sheet of plywood, how much did the sound material cost him to cover the plywood?  

Yeah, I missed that.

But, to salvage my point , the cost of the sandwich is $70 figuring you used 1/3 of the $30 roll. And, if you don't sandwich another 4x8 sheet, the cost is still $90.

Thanks for more info Moonman.

As I am also planning a module layout, this layered foam sandwich really interests me.

If you don't mind I have a few more questions.

"The floor underlayment is layered to hold fasteners well."

What exactly is "underlayment"? I'm guessing this is the thin layer that goes on top of the foam. Is it some composite material? I doubt it can be plywood for $15... How durable is this material? How does underlayment compare to 1/4" luan plywood?

How is the underlayment secured? Glued to the foam and then the track screwed to the underlayment?

I wonder if short screws into thin underlayment would be enough support for trains. This especially concerns me since I am planning a standard gauge layout with heavy equipment.

And lastly, how would you plan on you cutting and trimming all three layers so that they make a clean mating edge on the modules?

Thanks for taking the time to share this info. I am in the planning stages of a modular 13' x 15' standard gauge layout and this layered foam top technique may work for that, i. e. where sound deadening and weight are more important than cost per sgft.

Bert

Mr. Nabisco,

Underlayment looks like luan, is thin 5-7mm and is used as a smooth surface when installing a new floor over an old surface or a plywood floor deck. Luan uses more thin layers than underlayment and is meant for the top red\mahogany looking wood as a finish surface,ie. door. They are around the same thickness. It has three plys.

I don't think it would matter much if you screwed the sandwich together and used short screws to hold the track.

I would cut the module top pieces before assembling. Drop them into a frame with a rabbeted edge. Use the Lionel specification manual for some ideas.

Oh Dave.

Thanks for the response Moonman. I hadn't looked at the Lionel module spec manual. Some good tips there.

Two more questions then I'll let this roll in my brain for awhile...

Screwing the sandwich together from the top? Doesn't this stop the free floating foam layer idea?

Wouldn't securing the sandwich into a rabbet edge also end up securing the top to the frame and so transmit the sound/vibration to the frame?

Seems to me you'd want the top layer/underlayment to be isolated and attached to the foam only...

Bert

There's only so much you can do. Preventing the speaker effect from resonance on the wood is the big part.

You could use brads or small finish nails. It has to be attached somehow. Glue didn't appeal to me. I want to be able to replace a damaged deck piece. Stuff happens.

While the screw sound transference is technically correct, I believe it is minimal. 

Well, excuse me then. Just making a joke of my gaff.