It's become apparent that I need to redo all my roadbed (already). I need a more consistant support under my trackage. I also need it to be somewhat water/weather proof. One idea that crossed my mind was to rip a sheet of concrete backer board into 4" strips (each 8' long), stack the strips three deep (approxamately 1") and use as roadbed. I'd overlap the ends of each layer about a foot or 18" to form a more unified roadbed. I could easily cut radiused pieces for the curves as well.
Any thoughts or feedback before I spend my few remaining pesos on backer board?