I laid my track on a dense foam underlay called Tessamol which had a high strength glue on one side, I used the glued side to stick onto cork floor tiles. Ballasted the track with loose ballast and eye dropper. It worked well, did not transmit much noise and was quite quick to lay. Also tried it reversed with little difference. The Tessamol was used by an HGV Trailer builder I used to have to visit for servicing and was easy to buy from their stores. Like all good stuff not so cheap!
Different subject, Mayer, do you remember Colin Dukes from the Festiniog Railway From your Wales days?