Suggestions for sound dampening

If you have been on the forum for more than a month I am sure you have heard of homasote by now. Check it out it works great. Also because fastrack is hollow on the inside consider putting some sound dampening material inside the hollow space. Also I don't think you are going to get results you want without anything thick  especially since you are using fastrack.

I covered my layout with 1" foam. Used 4 x 8 sheets from Lowes.

I've read a fair bit about the homasote, but it sounds like it's prone to making a big mess. Standard sound board from Home Depot looks like it's easier to deal with, work almost as well, and not be quite so prone to mess making. 

its not that messy since you wont have to cut it. The sheets come in 4x8 sections and are easy to screw down on top of the plywood.

trust me. fast track is one of the loudest tracks in gauge do youself a favor and get homasote

I have fastrack on my layout, and used 1/2 inch dense foam 4x8 sheets with aluminum foil on one side. This has done a lot to reduce the track noise, but as previously said, I might go back and fill the track void with soft foam in the future.

I used 3/8" anti fatigue matting.  Lowes used to sell it, a 30" wide roll sold by the foot.

I cut it into strips with both sides beveled, using my bandsaw.

It made the layout quiet but as soon as I applied ballast it caused the sound to increase.

The matting turned out to be cheaper than cork roadbed.  You could even cover the entire surface of the plywood, fasten it down with spray adhesive.

I used bubble wrap used for insulating ductwork (has metalized film on one side and very heavy duty) on top of 1/4" plywood tables for my Christmas layout this past year.  Covered it all with snow blankets used for Christmas villages.   Never heard any real sound from underneith the tables.   Used both fastrack and tinplate- both were not fastened as this was a temporary layout.   Excellent results.