Building a 6' X12', has anyone?

Foam won't reduce noise to any real degree. Some people claim it does but I suspect their perception is blinded by a placebo effect. I actually tested it with a dB meter and it only dropped the noise by ~5dB. This was with the same train, same track, same location. Only difference was the foam. I also spoke to a professional sound engineer about this and he confirmed that foam is a poor choice. Long story short, foam is too dense, too flat and too rigid to effectively deaden sound. Look inside a recording studio and you'll notice the foam they use is soft, triangular and porous. Screwing it down will only make things worse. If quiet track is important you'll need to go with Atlas or another solid rail track. If you've already bought a large stock of FasTrack (my situation) your best bet is to fill the cavities in the track. I used Fusion Fiber which was pretty easy too apply and easy to remove, others have used 2" foam tape. Some have proposed spray foam insulation but that is a permanent solution and has the potential to get rather messy. Even then it's still not going to be as quiet as a solid rail track and the actual dB don't go down by all that much. It does change the tone of the track noise. Not nearly as sharp and harsh sounding, actually sounds more like a real train. 

Folding tables should  be fine though my one concern might be getting them all at the same level so you have a perfectly flat surface. If they have adjustable/leveling feet you should be OK.  

FastTrack is pretty good about staying put without screws. If you are worried about it - say a remote, hard to reach corner - and you're using foam screws probably won't be a very good solution. My layout has a couple of very remote corners that I REALLY don't want wiggling apart. To help hold them in place I used some wooden toothpicks driven though the screw holes in the FasTrack. The toothpicks are pointy on one end but flat on the other. I painted the flat ends gray and simply pressed them in. They're just as secure as screws and actually look better than having empty screw holes in the track. Also easy to install and very cheap. They're plenty strong to hold the track in place assuming you don't need to tip the table up onto its side.

I am temporarily on banquet type tables now, 30" x 96". I use the underlayment used to absorb sound under laminate or hardwood floors. I used the db app also and get the 21db reduction the manufacturer claims. I placed synthetic felt over top from JoAnn fabric. It comes in 60" wide lengths. It's a 2mm thick product. Available at the home stores or a flooring store. The foam does nothing for the sound absorption.

I am using FasTrack. Atlas or Lionel O, Super would be very quiet. Now, the train cars are making most of the noise(Passenger, box, hoppers, caboose. Little sound chambers.

Foam is definitely the best for the landscaping. perhaps foam on underlayment would be what he needs.

So what I'm guessing is that the Fastrack also amplyfies the noise created by the hollow/tunnel effect underneath? Would small popcorn placed and forced under the fastrack plastic cavity reduce the noise and vibration also? Otherwise, I have a good source for felt material also.

As to the tables, he says they are all the same height.

Not to be a downer, but I have used foam on top of folding tables the past 2 years for Christmas layouts and it has been very noisy.  I have thought of putting a buffer layer between the track and the foam to see if that helps.

I'm sure you will get responses from those more experienced in noise control than I am.

Indoor/outdoor carpet will work well for noise control.  Also on my layout I put a layer of celotex or soundstop on top of the plywood, then covered it with indoor/outdoor carpet since I was going for a more toy look than hi-rail.

I'm sure you could skip the carpet step and go right to ground covering on top of the sound boards or accoustic tile (an other option).  Also, some have reported good results with window sill tape.

Ultimately, fastrack is perfect for carpet layouts in the home where the annoying sounds get easily absorbed by the carpet fibers and the carpet pad.

Another trick is to keep the speeds down to realistic levels which will be proportionate to the noise it will generate.  That's true of any track system.

I'm with Paul on this one.

Soundstop is a world better than foam as a sound damper.

It is DESIGNED for that function.

It is easily broken / cut so you can sculpt a layer of foam under it and get deep ravines if that is what you are looking for.

It is also fairly inexpensive compared to homosote and it absorbs sound better as well.

Another thing to do for sound - Put a felt skirt on the tables. It will reduce the noise a lot, but not as much as the Soundstop under the track.

Its a bad idea,do it right.

Key here is the softer/more porous the substance the better the sound reduction. Again, look inside a recording studio or anechoic chamber. Felt, carpet, foam underlayment are all good choices. Rigid foam and plywood are not. This is also why symphony halls which are have long drapes along the walls have better acoustics than a concrete basketball arena. 

josef,

    I am not big on the folding tables for setting up a layout, however if you do, use 12" sound obsorbing block ceiling tile, with fairly thick in/out door carpet in what ever color makes you happy, over the sound obsorbing tile, this sets up a very silent running layout.  Using sound obsorbing ceiling tile and the carpet your FasTrack will run without hardly any noise at all, we engineer many of our FT layouts in this manner.   We have been using the Green in/out door rug on the Christmans layout, in the formal living room and still sit & entertain while the trains run. 

PCRR/Dave