Sound deadening material under cork roadbed - Does it work?

A video showing a recent experiment I conducted to decide whether or not to add an additional layer of rubber under the cork roadbed in an attempt to reduce track noise.
Sourced a roll of 3mm (1/8") recycled rubber matting from Home Depot for $1.40/square foot. Set up a 12' test track with 6' of the track sitting on cork, on top of this rubber. The other 6' of track the traditional method of cork on plywood roadbed.
Results are that you can audibly tell the rubber reduces the track noise slightly and confirmed it with an iPhone app showing the sound was reduced by approximately 5 dB.
Track was Walthers Sinohara code 83 secured to the midwest cork roadbed with silicone. The cork was secured to the rubber and to the 5/8'' G1S fir plyood with the same silicone. Freight cars used for test were Intermountain, Exactrail, Intermoutain to try and keep the sound the same both directions of travel.
After posting this video, a lot of modellers left comments with other options or ideas for sound deadening. Here they are compiled into a list.
Home Depot recycled rubber matting:
3mm 24"x54'' = $13.00/9 sq.ft. = $1.40/sq.ft
3mm 27"x10'' = $31.97/22.5 sq.ft. = $1.42/sq.ft.
*5mm same sizes also available but more $.
Sonapan 1/2'' sound deadening 4x8 sheets
Homasote 1/2'' sound deadening 4x8 sheets
Auto Zone thin rubber matting for automobiles/dynamat/mass loaded vinyl. Mass loaded vinyl - $50.00/yard = $5.55/sq. ft.
Dollar store 1/2'' thick foam rubber interlocking pieces for childrens play areas
Fibre type sound deadening material
Put layer of rubber in between where benchwork attaches to walls to mechanically detach it.
Roxul sound batting underneath layout when complete.
Poured concrete subroadbed.
Heavy ceiling tile.
Blueskin waterproofing material from Home Depot:
6''x50'' roll = $34.00 ($16.35/sq.ft.)
9''x50'' roll = $46.41 ($14.85/sq.ft)
36''x66.7'' = $140.00 ($8.39/sq.ft)

[@apocalypserailroad9047]

Wood is a resonator! That's why it's used to build guitars and other "wood" instruments. As a luthier, we would rap on a piece of wood with a small rubber mallet to get an idea of how it would resonate, to hear it's tone qualities. Yes, some woods are less resonate than others, but ALL wood is resonate. Add to that, plaster, Styrofoam, etc, etc, for landscaping, and you effectively build a drum. To stop the drum effect, fill all chambers with something that will stop the resonance. You can use wads of newspaper or pillow foam you can buy by the bag at Walmart. Depending on how far people want to go (such as myself, yes I'm an insane maniac), there are many things you can do to deaden acoustic resonance. In my first home, I built heavy wooden frames, and filled them with 1/4" concrete as a base. That's going to offer "as dead as it gets" qualities. AMI roadbed was used, and is extremely dense. Although it's no longer available, you can still buy it by it's construction name of butyl tape and/or putty tape and/or pipe wrap. On my new layout, I'm trying a little different approach. Instead of a complete concrete table slab, I will be experimenting with a poured concrete sub-roadbed. Then I will be using the butyl tape on top of that. The main table is built of wood and pink Styrofoam. If it doesn't work out the way I plan, then it will get ripped up and another thin concrete slab will be poured. Also, another thing to think about is your rolling stock. Most rolling stock are big hollow drums, rolling around on metal wheels, and resonating back and forth with the roadbed/sub-roadbed. Try using something in your rolling stock to insulate and stop the resonance. Pillow foam works well for me, you can cram a lot in there! ;) There are many other things you can do to deaden resonance, such as either not connecting your tables to your walls (unless they happen to be concrete) or using a heavy rubber materiel between your wall and table connection points, etc. Have fun. P.S. I hear Homasote makes for a good sub-roadbed/roadbed for deadening, but I have yet to try it.

[@BArailsystem]

Wow great information thanks so much for sharing. After I read your comment I did a lot more reading. Like you say this is resonating sound we are dealing with. Only way is to go with something that doesn't resonate like concrete as you say or mechanically detach it. Glad to hear you say that putting insulation inside the framework once complete will also cancel out the sound. I am for sure going to try that once I get to a more complete stage. Another great point about the rolling stock. Another idea I have heard is filling them with sand. I considered Homasote, I wish I could get my hands on a piece of it to test but according to their website it's not sold in my city. Sonopan is similar product but same problem with availability. Thanks again for your insight. Much appreciated!

[@apocalypserailroad9047]

I have seen Homasote here in Ohio at Menards, not sure were you're located or if you might have a Menards in your area. I have also seen it at a few different Lowes locations, so maybe check there as well. One other option I totally forgot about because it's been so many years since I used it, but that is flat ceiling tile! When I was a teen and young man still at mom & dads house, that's what I used in place of Homasote for hand-laying my track. It worked incredibly well for hand-laying, and as I remember, wasn't to bad as far as sound went. It's been 38 or so years since then, so my memory is a bit foggy on how it sounded. Back then, we didn't have sound systems to worry about, and many times guys really liked having a lot of natural noise going on to add to the railroading insanity!! ;) Anyway, you could probably grab a single piece of ceiling tile for a couple of bucks, just to give it a try and see how it sounds. Just try to find the flattest, and densest stuff you can. Also as a side note, I always cut my tiles using a simple carpenters utility knife, I never used a power saw. Some ceiling tiles contain bad stuff you don't want to be breathing, so either cut by hand or get the appropriate dust mask for the job. Glad I could help you out with some ideas! Have fun!

[@BArailsystem]

Apocalypse Railroad No Homosote or Sonapan within 100 miles of me unfortunately. I live up in central Alberta, Canada. You'd be shocked to see what we pay for a sheet both with our lower dollar value and then the increased shipping costs. I looked into Mass Loaded Vinyl (used in car audio) as well, but at $5.50 per sq.ft. it's 5 X as expensive as the heavy recycled rubber I found. I will look into ceiling tiles and add it to the master list in the video info, thanks for the heads up on that one! Ben

[@PeterCPRail8748]

Another well explained tip to make a layout more sound disapating

[@BArailsystem]

Thanks Peter.

[@Trainguy05]

Great video always enjoy and look forward to the next one. Three thing that might also help with noise reduction; you can use a liquid rubber on the underside of your scenery (it comes in a spray can (flex seal or something like that) or a gallon can to be applied with a brush like paint)); put up a fabric curtain below your fascia also helps; and finally carpet your floor. I used hi traffic carpet squares and it made a noticeable difference. Thanks again for the videos and Happy Holidays. Charlie

[@BArailsystem]

Those are all really great ideas Charlie, thanks for sharing. I'm definitely going to do the curtains and carpet. Did not think of applying it to the underside of the terrain. Happy holidays to you as well! Ben

[@eseries844]

Liking that CNNA covered hopper used in the experiment! Good to think of these things before more track gets laid!

[@BArailsystem]

Thanks Eric! Thought you might like that. Note that it was a made up Intermountain foobie road number, not the prototypical and extremely rare CN 371897. Happy holidays!

[@brettroworth751]

Try issuing rubber or acquista seal between the plywood and frame as well it will stop the frame from transmitting vibration from the train.

[@RailwayWorld]

Interesting idea putting sound insulation under the benchwork when completed, never thought of that, could work pretty good.

[@BArailsystem]

Yeah, I think it is a great idea. I'm definitely going to try it out when I get to that point.

[@wizardgaming669]

My N scale layout is 3/4" plywood with 1/2" pink foam from Home Depot. I then used that grey soft foam roadbed that every hobby shop sells, I think it's woodland scenics. It's honestly really quiet. And since I live in southern Alberta it's always dry so I haven't had problems with wood warping or expanding. Cheers.

[@BArailsystem]

Thanks for the info on the N scale sound. I guess with wheels half the size we could expect half the noise and double it for O scale?

[@wizardgaming669]

BArailsystem I found the best sound deadening stuff is those half inch thick foam rubber interlocking floor mat for kids play areas. I bought two at the dollar store and gave them a test. They are extremely thick though, maybe good,for G scale.

[@BArailsystem]

Tommy Wizard Thanks for the tip Tommy! Seems that there are a lot of options out there. I will compile everyone's suggestions into a list in the video info.

[@MLWQC]

Interesting video. I found that as soon as you ballast the track you will get "sound" . Nice progress on the layout.

[@BArailsystem]

Hi Syl. I found that too on my old layout. It was ballasted track on foam roadbed on 2'' of foam so the wheel noise was very loud on that layout. Thanks :)

[@MLWQC]

Yes indeed. Something I have found is if the ballast is well done (nicely packed, glued properly, dried completely etc.) the increased in sound is not overwhelming. When I do Ops what does makes lots of noise is.....locomotive sounds! Prime mover, bell, horn etc.I have reduced the overall volume again and that helped a lot. Cheers!

[@aviationcalgary4110]

Hello Ben I agree in my opinion the rubber is not makeing much of a difference.

[@MLWQC]

I agree with this comment as well.

[@aviationcalgary4110]

MLWQC yeah I Dont Blame You

[@SeaboardCentral]

I have a Kalmbach book that addresses this issue and the author discovered that the best combination was camper top tape over cork roadbed. I believe it is the same material that is put inside frames of automobiles to reduce noise. Tim

[@SeaboardCentral]

I meant cork over camper tape.

[@BArailsystem]

Hi Tim, What was that book called? I've heard of this camper tape, I believe it's similar to the rubber material my friend used on his layout called Blue Skin: www.homedepot.ca/en/home/p.blueskin-weather-barrier-6-inch.1000403475.html Thanks for the tip. Ben

[@notabob7]

You should also consider which adhesive you use. It makes a difference when it comes to noise. More rubbery, latex caulk adhesives tends to result in much quieter track vs. those that soak into the cork and/or rubber. I've been using DAP Alex Plus for securing track to cork and Loctite PL300 for securing cork to subroadbed. It's also rubbery in nature, is safe to use with extruded foam insulation (pink or blue foam), and also works pretty well between cork and plywood.

[@BArailsystem]

Very good points here! I used a DAP silicone for this test. I like using it for the track it works very well. I got some no more nails for the rubber which I think is similar to PL300, a heavier rubber type construction adhesive. Thanks for sharing your techniques!

[@FishplateFilms]

5 Degrees difference Ben????? You're living in heaven mate...LOL, I'd be happy with a 25 degree difference! Personally I wouldn't worry about track noise, you wont be going that fast and a few locos running drown out other noises. I actually miss the wheel noise over the joins!, you don't hear it anymore with all that engine noise! Up to you of course but I would spend my money on something else? P.S. the train room was 37 yesterday..LOL Cheers Gregg.

[@BArailsystem]

Hi Gregg, Over the day yes, but helps that 80% of the basement is underground I think. You're definitely right about trains not going that fast. Reality will be the noise will be much less most of the time. However, since I get only one chance to do the roadbed and I am OCD about the wheel noise I think I am going to go ahead and use this rubber to try and reduce it a bit. Holy smokes 37! What was the ambient? I worked in -30*C ambient (-40 with windchill) last week at night. I think my bones were frozen when I got home. Ben

[@FishplateFilms]

Ben , basements are great! I don't know why we do't use them here to escape the heat?? Your old layout on foam would be much noisier than the thick ply , but as you say , if you'll sleep better at night, then go for it! :-). Just make sure it still leaves a firm road bed, not like my old foam underlay!, but it looks ok on the video. Ambient on that day would be about 39, not much cooler in the shed when everything heats up! A few weeks ago , it was 37 and we measured the ballast temp and it was 49, and under the ballast was 63! Any tool you left out would burn your hand . I till think thats better than -30 mate, what were you doing out in that? Gregg.

[@BArailsystem]

I'm not sure why either? Maybe because you guys get larger precipitation events? I should have shown it better in the video but the rubber is very dense, firm and has no give. Similar to cork. Shouldn't be a problem. My old layout you had to be careful when cleaning the ballasted track as you could push it down with your finger and it would crack. Wow, that is incredible that you can't leave tools out. I guess if you left a tool out in -30 here it would also burn your hand, just in a completely different way. What an amazing planet we live on. Also crazy that your ballast was 63. Did you leave larger gaps or lay your track in the summertime to counter the expansion? Just another day at work. I work at a petrochemical plant and it's a 24 hour operation. Rain, shine, blizzard, heat wave we have to keep it running. Although extreme cold is definitely the most challenging.

[@FishplateFilms]

Tis amazing Ben, thats for sure! The track is stressed/stretched when laid depending on the ambient, none in summer and a lot in winter. When it heats up, the expansion takes out the stretch...usually but not always.LOL Laying welded rail is a tricky business, in cold and heat extremes! At least in the cold Ben, you can always rug up, there's only so many clothes you can take off when it's hot...LOL Gregg;-)

[@BArailsystem]

Interesting! Very true about layering too. Stay cool my friend!

[@BriansModelTrains]

Nice work Ben. Been a while since I checked out your Train videos and new layout. Every 3 db the human ear can hear a difference. Play Safe!

[@BArailsystem]

Thanks Brian! Now that is cool I did not know that. Proves that I wasn't crazy and could hear an audible difference.

[@BriansModelTrains]

Your layout will be wonderful. I have not touched my Trains in about 7 months. Hopefully time will clear up for me soon. Merry Christmas & a Happy New Year. Been saving your videos for when I have time to enjoy them.

[@BArailsystem]

Brian Thanks Brian. Sorry to hear that, life gets in the way sometimes for sure. Merry Christmas to you and your family as well. All the best in the new year!

[@davidmuse7004]

Great video and very interesting. Thanks for taking the time to experiment and share your findings. If I may offer, I have been using DAP320 to secure roadbed and track to 3/4 inch foam base and have never had a problem with adhesion. You might want to give that a try if you don't wanna use nails. Thanks for the video!!! D. Muse

[@markcrocker934]

Interesting. Just one other consideration - I have used cork and flexible rubber/foam on my layout and when ballasting and other groundcover is added, the flexible materials can create issues with cracking. You need more glue to secure it but if you push down hard, the ballast will give because it is sitting on a flexible surface. Cork doesn't move. Just something else for you to think about. I've also found that lots of model trees absorb sound. Cheers!

[@BArailsystem]

I had this exact problem on my old layout with foam roadbed Mark. Had to be careful when cleaning the track. I never really showed it but this rubber is very dense, heavy and similar to cork. It really doesn't have any give. Interesting that you found the trees absorb sound. Makes total sense because this is resonating sound we are dealing with and the trees would act like mini shock absorbers maybe. I should remember to test again when it's all finished. Look for that video in 2033 :)

[@markcrocker934]

2033? You'll be about thirty years ahead of me mate!! Glad the rubber isn't going to create those problems with the ballast. In hindsight I would have used all cork rather than some of the Walthers roadbed in places. We live and learn. Also with the noise issue - I have got storage under the layout and this helps to remove the 'soundbox' issue you are anticipating. Looking forward to watching your progress.

[@BArailsystem]

I will have storage underneath as well Mark and am in the same boat. Good to know that it helps.

[@GooseinTheCabooseProductions]

Very interesting video man, especially the idea of filling the underside of the layout with foam. The only thing I can think of that might be a drawback is the possibility of the stuff getting into the wiring switch machines and that sort of stuff. Although if it's rigid, that might not be a problem. Just my two cents worth.

[@BArailsystem]

Good points Jacob. Care would have to be taken around switch machines and electronics. I am thinking of the "bat" material that is semi rigid and when pushed in between the joists has enough rigidity to hold itself in. Still may want to staple some sheet plastic underneath to hold it all together. Cross that bridge when we get there.

[@MZTrainsChannel]

thank you

[@WestCoastRails]

Great video Ben. I'm just curious. What if you tried the rubber on the bottom side of the plywood? I was looking into this a awhile back. Could the rubber keep the wood from acting like a snare drum? The track vibrations transmit down through the materials then the wood being the hardest material will amplify the track noise, which is the metal wheels on metal rail. Hmmmmmmm

[@BArailsystem]

Very possible Greg. As Apocalypse Railroad suggested, taking it one step further than that and putting a piece of rubber in between the connection of the benchwork to the wall thereby mechanically detaching it from the wall. This would stop the resonating sound from reaching the wall. All good things to consider. However I've gone way to far now to go back and take apart all my wall connections so I'll just have to deal with it as I can by laying rubber under the cork and creating a separating layer between the cork and the plywood subroadbed. .

[@disturbed1954]

I muse homeasote that comes in a 4'X8' sheet 1/2" thick, it makes a world of difference, couldn't stay in the shop without it unless you had ear plugs!

[@BArailsystem]

Hi David, I've heard good things about Homasote, unfortunately I can't get it in my city and would have to go to Calgary or Edmonton to find some. There's a similar product called Sonapan but it's quite expensive at around $30/sheet.

[@MBrailfan]

Interesting video! On my layout I have a layer of 2" pink foam and cork roadbed and I don't seem to have nearly as much noise as you do. Even with a 15-20 car train running a decent speed I can barely even hear it if I stand 10 feet away. I don't find it disruptive at all, although I am on DC so it is nice to hear something as the train is running :)

[@BArailsystem]

I think it might be something to do with my benchwork being attached to the walls. The resonating sound is able to transmit into the wall structures and sound louder. Another friend of mine did a free standing L-girder benchwork and his layout also had a lot less noise.

[@MBrailfan]

that's neat. I never thought having it attached to the wall would make the sound louder. TIL.

[@RyanTheRailfan]

Interesting, great video Ben -Ryan

[@BArailsystem]

Thanks Ryan

[@Delores227]

Brewing video Benjamin I see you got the truck running have you got any grapes plan also that video you uploaded to Music go of your Christmas tree train made me upset it was heartwarming I see you're now a father. Did you show me your family you're really awesome merry Christmas hopefully the new year brings you a lot of comfort and joy Delores

[@BArailsystem]

Thanks! Brewing video? My family hasn't guest starred in any videos yet. Maybe my son will start helping me do the videos soon, he is almost 2. Merry Christmas to you as well Delores. All the best in the new year!

[@onkyonky4740]

every 3dBa is a doubling as it is a linear scale so 5 dBa reduction is a reduction of the noise to a quarter of whaty it is without the rubber

[@BArailsystem]

Thanks that is a very clear explanation!

[@jonnyspeed]

That's significant. +10 dB is the level of twice the perceived volume. So - 5 dB would be roughly half as loud or a 50% reduction in volume.

[@BArailsystem]

Good to know Jon, thanks. A couple people have pointed that out which is good because I didn't really understand the decibel scale.

[@jonnyspeed]

Sorry, didn't see the other comments. Just wanted to point out that you were on to something.

[@BArailsystem]

No problem at all Jon. Somethings are a steep learning curve for me and I appreciate all the help I can get! I should have worded my response better, 3 modellers gave me three unique pieces of information on the dB scale and I am grateful for any advise. Happy holidays! Ben

[@Bruno.Trains]

Very interesting ,,, many thanks

[@CanadianRailRoader]

Assuming it's artificial rubber and not natural rubber (which is probably a correct assumption on my end) at least from my experiences is that rubber has a fairly small expansion and contraction on temperature swings.... In a basement like yours it's very likely that there will be no change at all that's even measurable. I'd say you'd only notice a change if there was around a 40 degree fluctuation between temperatures which is very unlikely inside a house.

[@BArailsystem]

Not sure, it just said recycled rubber product on the label so who knows? I agree with you, I mean when talking expansion its fractions of a mm for one degree. Not really an issue. But the metal rails are a different story. My friend had an actual sun kink show up on his layout in the summer. Just like on the prototype.

[@davidmuse7004]

Also, Auto Zone and a few other auto supply stores and shops sell a thin rubber mate for installation in automobiles, don't know how much you get and how much it cost, but it is a little thinner if that matters and designed for sound abatement.

[@BArailsystem]

Thanks for that tip David. The auto sound deadening material was something I didn't consider. I will have to look into that. I'll give that DAP a try, I did use a DAP silicone for the test and it works fantastic for cork to plywood but the cork to rubber and rubber to plywood wasn't very secure. I did get a tube of No More Nails all purpose construction material and I am going to try that out on the rubber as well.

[@lepetitnabot]

You could try sound-deadening products like those green fiber panels that go behind drywall (forget what they're called), or Dynamat insulation for automobiles... not sure how economical that would be, though. I will echo the comments of other, though. I really don't understand the fascination with super quiet running trains.

[@BArailsystem]

I think your talking about Sonopan? Green sheets they use in between drywall for sound proofing. A buddy of mine used it in his home studio. It's a little pricey around $30.00 per sheet similar to homasote I think. I wish I had some to test. The only thing I am leary about is the time and work to cut all those pieces out again with the jigsaw. This rubber is really easy to work with. The wheel noise is just personal preference. My last layout was really noisy and it took away from the sound equipped locomotives once you got a train rolling at a decent speed. So this time around I want to try and do something like Pelle Soeberg did on his Daneville layout to knock the wheel noise down. Definitely won't get rid of it, just make it a bit quieter.

[@Rif-Raf]

Hi, didn't you used to run your trains at 40 MPH scale? Are you still planning on running at the same speed on your new layout? Also, why would you be concerned about the sound level? I don't understand why you are worried about it? I could see if you were running Gauge 1 trains. At any rate, best of luck! Seems you'll have a very precise layout! Lots of excellent work!

[@BArailsystem]

Hi Paul, Yes all my locomotives top out at 40 scale MPH. Which happens to be the top end of most modern locomotives these days. Probably not all the time but sometimes it's fun to run a big train that fast. The subdivisions I am modelling have speed limits above that so it won't quite be prototypical but a 30 car grain train at 40 scale MPH looks pretty fast. It's just a personal preference. My last layout had really bad wheel noise so this one I want to try and reduce it. Especially since I plan on running a sound car in the middle of trains eventually. Thanks for the kind words! Much appreciated. Ben

[@joesaurina1402]

I've used a fiber type sound damping material that works pretty well until you ballast, then it's intended advantages seem to dissapate . But it was better than the Woodland Senics foam and cheaper.

[@BArailsystem]

Thanks for sharing your findings Joe!

[@NS3644]

what about trying the self adhesive car audio sound deadening stuff they use inside of car doors etc.

[@BArailsystem]

Considered it and even called around to a couple places but it was 5x as expensive as the recycled rubber from Home Depot.

[@trainsontuesday]

I have tried various sound deadening methods but I find that as soon as you ballast the whole thing becomes a tight drum skin. Plastic wheels deaden sound but they are certainly out of fashion so bottom line, embrace the sound. Real railways are rarely quiet. David.

[@BArailsystem]

Hi David. I found that too, but what I am doing different here would be that the track, ballast and cork would all be sitting on top of this rubber. Hopefully it will make a difference when the track is ballasted as well.

[@trainsontuesday]

I shall keep watching to see the results. All the best, David.

[@gogenea]

I guess my question would be in this age of model locomotive sound why would you not want some wheel/rail noise that is so common in real life?

[@BArailsystem]

It's just the "whirring" sound from the wheel noise I don't like. My old layout was ballasted track on foam roadbed, on 2'' of pink foam it was so loud when you got a train going. I'm bound and determined to try and reduce that a bit on this layout. One benefit is that the locomotive or sound car sounds can be turned down a bit if it doesn't have to overcome white noise coming from the rest of the train.

[@qwerty112311]

I saw some guy using drywall instead of plywood, which I think would certainly have some sound dampening wualities

[@BArailsystem]

I think it would as drywall is very dense. Relatively inexpensive as well. That would be a nightmare of dust though to cut all that drywall into curved shaped pieces to match the plywood.

[@zemoosehunter]

run it on the carpet underlay

[@farmerdave7965]

And then you have sound in your locos so all that sound proofing did not matter.

[@BArailsystem]

All the more reason to soundproof the track work. The goal here was to reduce wheel noise...

[@johntimney556]

C