Tabletop question: Foam on plywood

Even with cork roadbed, or the foam, the track will transfer a lot of noise to the benchwork like a drum. I used 5/8 insulation foam on top of my 3/4 plywood and should have used zip ties to connect the track vice track screws, which is going to happen when we move and my layout gets rebuilt.

@Ron_S posted:

Even with cork roadbed, or the foam, the track will transfer a lot of noise to the benchwork like a drum. I used 5/8 insulation foam on top of my 3/4 plywood and should have used zip ties to connect the track vice track screws, which is going to happen when we move and my layout gets rebuilt.

There is really no need to use screws on any permanent layout as the glue from ballast will hold everything firmly in place.   The only exception I can see to this is where you have back to back switches where the amount of ballast or glue is slightly reduced so as to not foul points or switch machines.   My old layout had zero screws in it as will my new one.   Both used Atlas track and switches.

To answer the OP's question - no, there are no drawbacks to not using foam on top of the plywood.  That being said, it's obvious you can reach all areas of your layout so you don't need the layout to support your weight.    I would seriously consider not using plywood and using foam instead.  It's so much easier to do scenery using foam as your base rather than plywood.  As for the noise, the trains are loud anyways.   It's only marginally louder with foam vs plywood.

-Greg

I completed a 10'-by-5' layout in 2019 (see cover and article in OGR Magazine Run 304) with 1/2-inch plywood topped by layers of extruded pink foam that were stacked and carved to create hills and valleys. There is also a terrain construction article in OGR Run 316. The track is five inches above the plywood. The riverbed is on the plywood. I glued cork roadbed atop the foam with yellow carpenter's glue and used Atlas O track screws into the cork and foam to secure the Atlas O track to the layout surface. This method produced a layout with a river valley, a hill/tunnel, truss bridge and trestle, although it was a lot of work. For me, layout noise has not been an issue. About all I hear when I run trains are the motive power sounds. This method is useful for creating variations in terrain height. The first video below gives you a look at the layout.

I also have a 12'-by-8' layout with Atlas O track and cork roadbed directly on plywood. It's noisier but I don't find it objectionable and the engine sounds are mostly what I hear. See second video.

MELGAR

I understand using extruded foam to create scenery but I don't understand why anyone would want to use it as a surface. It is too easily damaged, not to mention the sound issues others brought up. What am I missing with regards to using extruded foam under track?

@turkey_hollow_rr posted:

I understand using extruded foam to create scenery but I don't understand why anyone would want to use it as a surface. It is too easily damaged, not to mention the sound issues others brought up. What am I missing with regards to using extruded foam under track?

Too easily damaged by what? How much weight do you place on the layout surface? I do not stand or crawl on the layouts. The surfaces are covered by structures, roadbed, plaster (in some places), ground cover and roads. The layout surface doesn't have to support anything heavy. The weight of a locomotive on the track does not damage foam, but foam is the best way to create realistic lightweight scenery. And, there are no "sound" issues in my experience.

MELGAR

I have 3/4" thick rigid foam insulation board from one of the big box stores glued to plywood. It was painted and turfed. I have kneeled, leaned and stood on it with no issues.

One advantage of using foam is that makes a nice and easy surface for mounting anything that has to "stick" into the layout, like trees, signs, crossing flashers, telephone poles, etc. 

@Richie C. posted:

I have 3/4" thick rigid foam insulation board from one of the big box stores glued to plywood. It was painted and turfed. I have kneeled, leaned and stood on it with no issues.

One advantage of using foam is that makes a nice and easy surface for mounting anything that has to "stick" into the layout, like trees, signs, crossing flashers, telephone poles, etc.

To add on - if you use any type of accessory the bases are easily embedded in the foam so the accessory is at ground height.   And if you like the MTH/Lionel buildings with the curb that's too high they are easily recessed in foam as well.  There's no hassle of cutting holes in the plywood and heck, did you ever cut a hole for an accessory base only to find you're directly on top of a support beam and have to cut into it (or move)?

-Greg

What Greg said ........ plus foam is great for carving out lakes, ponds, streams and rivers.

Let me offer a different suggestion/observation after seeing your photo:

1) Finish adding floor tiles/carpeting (think I see some black tiles) before you complete the layout. Soundproofing under the table makes a big difference.

2) Finish the ceiling and overhead lighting also. Basically I'm suggesting you finish your train room before doing more on your layout.  It will be so much easier to complete room construction without worrying about damage to your layout.

Yes, I made the mistake of completing my own layout before the room was completed. Fortunately, I had an excellent carpenter/drywall expert to bail me out!

3) No matter whether you use screws, glue, foam, or plywood, be prepared for your relative noise level to increase after ballasting. The rock-solid nature of a ballasted track ensures excellent audio transmission from the track ties to the plywood/foam/cork base. (I once tested rubber ballast but it was too difficult to lay down properly.)

I just used 3/4" MDF. Had plywood on an older layout. MDF is considerably less noisy. No foam used. Little more expensive for MDF but no cost for foam.

Oh Brother!  I only wish I had found OGR several decades ago.  I thought I was well ahead of the game when I screwed and glued homosote (sic) to the framework back in 1999.  It is so much better than the plywood we used 50 years ago too.  Back then Dad cut an old Persian rug into strips for under the track and used coffee grounds from his Deli for ballast.  Unfortunately the basement became infested with moths that loved the carpet.  Noise...I don't remember any noise, perhaps because that 44 foot long double loop of track was inhabited by Jesse James and other nefarious folk, or did  Joe Friday and Elliot Ness rule the day.  Nope...no noise back then.  Today...it is another matter, I may rebuild...but then again, I wonder why.   You guys are great - lots of good info in this thread.  Thanks

Bruce,

I remember reading somewhere that using diluted matte medium instead of glue helps to mitigate the sound transmission caused by hard glue.  It seems the matte medium drys  to a soft consistency instead of the hard structure of glue. I've not tried it yet, so I cannot give personal testimony. But it is on my list of modifications to try.

Chris

LVHR

Chris,

Yes, I used diluted matte medium (white stuff) from a squeezy ketchup bottle.  That was recommended at the time I did it 25 years ago. The ballast is pretty solid on my layout.

@Bruce Brown posted:

Let me offer a different suggestion/observation after seeing your photo:

"2) Finish the ceiling and overhead lighting also. Basically I'm suggesting you finish your train room before doing more on your layout.  It will be so much easier to complete room construction without worrying about damage to your layout.

Yes, I made the mistake of completing my own layout before the room was completed. Fortunately, I had an excellent carpenter/drywall expert to bail me out!"

Even with a dropped ceiling, take pictures of where everything is so you don't have to hunt and remove tiles all over the place for any repairs.

Some of my engines are silent conventional.  Diluted matte adhered ballast in my experience with two rail track over cork,  over 1/2" Homasote, over 3/4" Birch plywood supported every 16" makes for  loud running here.   I will not be adhering any additional ballast.   I may experiment with loose ballast.  It's fair to say I hate platform noise originating from the trains.   Some of the worst offenders are plastic road bed ready track.   When there is sound I prefer a scale level.

My three rail trains are run at about 30 scale MPH which quiets the sound levels.

On the other hand, with traditional tubular track there is a nostalgic value to the crass sounds of loud trains, it's just hard for me to hang around all that noise for any length of time. 

I was planning on using Loctite Powergrab to glue down 2" foam on top of my 1x4 frame on 16" centers.   Then cork roadbed or sheet cork on some spots glued down to the top of the foam.   I had also planned for a curtain around the base to also help mitigate extra noise.  For those with experience, will the track screws that pass though the cork and foam about 1" going to hold track well and not back out?   I have heard when you screw down track into foam it doesn't bite or hold well and eventually wiggles loose.  I had hoped the 1/8" cork on top would make the difference.   Yes?

@Bruce Brown posted:

Let me offer a different suggestion/observation after seeing your photo:

1) Finish adding floor tiles/carpeting (think I see some black tiles) before you complete the layout. Soundproofing under the table makes a big difference.

2) Finish the ceiling and overhead lighting also. Basically I'm suggesting you finish your train room before doing more on your layout.  It will be so much easier to complete room construction without worrying about damage to your layout.

Yes, I made the mistake of completing my own layout before the room was completed. Fortunately, I had an excellent carpenter/drywall expert to bail me out!

YES YES YES.  LISTEN TO BRUCE.

I've been finishing my basement for 15 years while I build the layout.  Dumbest thing I could do.  The drop ceiling I did last summer was incredibly difficult.

Learn from my mistakes.

By the way I use 1 inch foam on top of plywood.  I like it and do not regret that.  Do not used foam alone. It will become a giant speaker.  I have a custom removable all foam section of the layout.  It's louder that any other part of the layout.

Ron

To be clear, even the 2" foam glued to the frame is loud?  Or do you mean only the thinner foam?  

@Hp289 posted:

...  For those with experience, will the track screws that pass though the cork and foam about 1" going to hold track well and not back out?   I have heard when you screw down track into foam it doesn't bite or hold well and eventually wiggles loose.  I had hoped the 1/8" cork on top would make the difference.   Yes?

On my layout, the Atlas O track screws go through the cork and about 1/4-inch into the foam. The cork seems to hold them securely. If any loosen, I would use some epoxy on the screw thread to hold the screw in place.

MELGAR

@Hp289 posted:

To be clear, even the 2" foam glued to the frame is loud?  Or do you mean only the thinner foam?  

My guess is the size would just produce a different sound.  Don't get me wrong... It's not completely terrible, but it does produce more sound.  Listen to this engine and track cleaning car.

At :20 it enters the 2" pink foam bridge.  The rest of the layout is 1" foam on plywood.

This stream, loaded with helpful tips, has been hibernating. So I’m hoping the gurus awaken. My table is half inch OSB and I will be adding foam; for purposes of scenery. However, I’m not sure of the best way to “secure “ O tubular track to the foam. Thank you for your recommendations.

I've seen a few layouts with construction foam, but I went with Homasote on top of the Baltic Birch base, it's much better at knocking down the track noise.

Would it help to lay something like carpet backing (rubber?) under a foam sheet to absorb some of the sound?

Didn't realize that the ballast contributed to the problem - I guess that with the hardened/dried glue it becomes like plastic roadbed.  I hope to rebuild someday using Atlas and I want to improve my table construction a lot to cut down on the noise.

Homasote over birch ply here also. I have some cookie cutter sub-roadbed completely covered by homasote, and I have some sections fully covered with the plywood but the homasote on top is cookie cutter.  I've noticed the former is much quieter than the latter so at some point I'll go back and glue down pieces in the uncovered spaces as part of scenery.

If noise becomes an issue with the foam tops it may be possible to attach something to the underside to quiet things down. Homasote if it is available, auto parts stores carry Dynamat or some other dampening material. I don't know if ceiling tiles are dense enough to make much difference but that could be worth a try.

I have a few spots on my 16' by 20' layout that are 1" foam on 12" plywood. The rest has an additional 1/2 " ceiling tile layer and is much quieter than just foam. I use Fastrack and can run trains at 20 to 25 SMPH with sounds set at 50 to 60% with hardly any track noise.

@turkey_hollow_rr posted:

If noise becomes an issue with the foam tops it may be possible to attach something to the underside to quiet things down. Homasote if it is available, auto parts stores carry Dynamat or some other dampening material. I don't know if ceiling tiles are dense enough to make much difference but that could be worth a try.

I've discovered that the butyl rubber sound deadening mat for cars works really well on my suspended second level.  I'm about halfway done with it, (the easy half) and the difference in track noise on the finished part is pretty significant.

This is the stuff I am using, I got it on Amazon.

Excellent insights on the sound deadening. But, what would be the best way to keep tubular track in place?

@Tranquil Hollow RR posted:

Excellent insights on the sound deadening. But, what would be the best way to keep tubular track in place?

My opinion is to not use foam or OSB. My opinion.

@Tranquil Hollow RR posted:

This stream, loaded with helpful tips, has been hibernating. So I’m hoping the gurus awaken. My table is half inch OSB and I will be adding foam; for purposes of scenery. However, I’m not sure of the best way to “secure “ O tubular track to the foam. Thank you for your recommendations.

Carpet Tape! Double sided and works great. It is what I did and have NO PROBLEMS. You can even come and BALLAST it as I did and it will not magnify the sound. I have a 625 sq ft layout and used Foam glued, in some areas, to the plywood and not in others. Foam is excellent for scenery. You can make ditches, creeks, lakes, or build up for hills, and mountains. Trees insert easily (I punch a starter hole with an awl). I love it. Carpet taped my track and ballasted. Everyone comments on how realistic it looks.

@Tranquil Hollow RR posted:

Excellent insights on the sound deadening. But, what would be the best way to keep tubular track in place?

You can use screws - just don't have them long enough to go all the way through the foam; and put a little caulking on the tip of the screw when you insert/screw it into the foam.

Others have used dabs of caulking, hot melt glue and zip-ties to secure the track to the foam.

Thank you gentlemen.

I am using 4" foam on top of plywood, reason I did it was for some of the sub track level effects I want to do (or may do). I am still early with it so can't talk about the noise level, in terms of holding down the track if ballasting that will hold it. Screws should work, putting caulk or glue on the screw tip should work as long as the screw is smaller than the hole in the tie (if you screw the screw through the tie, the glue will be rubbed off). I plan on ballasting my track and using that to hold it down, have debated using cork roadbed under the track, not sure about the cost of that vs rewards yet (fortunately my track is not laid down yet, makes it easier if I decide to go with the cork roadbed.

Bigkid, I’m in a similar situation and getting close to when I will have to make a decision. Thank you for your input.

Interesting thread. It's just common sense to have your train room completely finished, including walls, lighting and flooring before you even begin to start building the layout. 1/2 inch plywood is adequate for the deck of the layout. You can dance on it. I don't understand people who think it needs to be thicker than that. Then 1/2 inch homosote or foam on top of that. Plenty thick and you can do any scenery, track installation, accessories, etc., with ease.

The reason I used Homasote was for it's sound deadening qualities, it does a much better job than construction foam.  Just take a piece of construction foam (blue or pink) and a piece of Homasote and tap on it.  The difference is obvious.  That also translates into quieter running so I can hear the neat sound systems I paid so much for.

@gunrunnerjohn posted:

The reason I used Homasote was for it's sound deadening qualities, it does a much better job than construction foam.  Just take a piece of construction foam (blue or pink) and a piece of Homasote and tap on it.  The difference is obvious.  That also translates into quieter running so I can hear the neat sound systems I paid so much for.

Ditto.

Great Lakes RR mentioned,

"A rookie mistake I made is that my tabletop is 49” tall. I’m 6-3” so it’s not the end of the world but I'm not seeking to make it taller yet with the foam"

I too found myself in a similar situation because I am building multi-level. My solution if needed will be to build a 2x4 or 2x6 framework on the floor of any viewing area. cover with plywood and maybe carpet squares for a step-up platform. Too high is better than too low.

I intend to use Homasote over 3/4 ply on table-top; however, after GRJ's recent comments considering his sound deadening mat, that is only a few MM thick; I may place a layer between Homasote and plywood.

Kevin that height of 49” will make it easy to work on. I think a layer of one inch foam could work for you as it would provide scenic options. You could leave your mainlines outside of the foam area. GRJ’s recommendation has a lot of merit.

Another consideration could be to cut the homasote to the track width. From what others have said, it’s easy to cut with a knife; a saw makes a lot of dust.