Hopefully this is the correct location, as there doesnt seem to be a dedicated forum for overall layout construction.  The day after Christmas I finally started something I've been waiting a good 8 years to do.......my layout construction has finally begun!

I wont post the design again here but below is a link to the post in the layout database thread going on the design forum: https://model-railroad-hobbyist.com/track-plan-database?page=37

I have become enamored with the flowing look of track built on spline roadbed. While I model in On30, the track gauge is the same as HO, it does require longer ties and more center to center spacing. With that in mind I lowered a section of my bench work about 4” below where the other, plywood, roadbed is already in place to allow a few more riders and some room for scenery below the track level. 
 

Hi Guys:

Got another question

When I built my test layout, I used 1/4" MDF with Homosate over it and then cork roadbed.  It works great in the sense that there is little to no wheel noise, and it was easy to lay track on.

Reading the articles on the Canadian Canyons project in Model Railroader, I noticed that they used 1/4 inch tempered hardboard with cork on it then the track.  if it would work, this would be great, b/c it would cut down the thickness of the subroadbed, particularly in the helix

I am having trouble with my swing bridge I use to access the center of my layout holding a consistent height. I suspect this has to do with the varying humidity more then anything else.

So I am considering raising my layout by about a foot and then using a desk chair to roll from the outside to the inside. It would be high enough so I wouldn't have to duck. I would put a couple of those plastic floor mats down that have spikes on one side to hold them in place on carpet.