I traced the templates and filled in the blanks between them using a pencil. This left the entire trackplan drawn on the MDF sheets. I also wrote the numbers and types of turnouts on the sheets. I mainly used #4 and #6 turnouts and wyes. I would have preferred to have used all #6 turnouts, but there just isn't enough space. I also transferred the industries' names from the sticky pads to the MDF sheet.
The photo below shows the trackplan cut out using a jigsaw. I preserved the scenery portions of the MDF sheets for now.
The modules I built have an inside depth of 1.5 inches. I cut a number of 3/4-inch plywood blocks that are 1-5/8 inches tall. I am using 3/4" plywood because screws will need to go into the wood later on, so I needed something that was wide enough. I carefully placed the sub-roadbed in the correct location. I then placed these blocks under the sub-roadbed to provide plenty of support for the MDF. I then carefully lifted off the sub-roadbed without moving the blocks. I marked the blocks' locations with a pencil along two of its edges. This forms a 90-degree corner and so it is easy to replace the block in the correct location at the correct angle. Using wood glue, I glued each of the blocks in their location, carefully placed the sub-roadbed on top of the blocks and then added a lot of weights (books, tools, paint buckets, etc.) on top of the sub-roadbed to clamp the blocks in place. I decided to glue the blocks down so that they can be easily removed in the future should I decide on a different track plan. The glue holds the blocks in place very well, but a swift blow with a hammer and the glue or block will break away.
Before permanently installing the sub-roadbed I wanted to provide support for the main bus wire of the DCC feeders. In previous layouts I used the suitcase connectors to hook up track feeder wires to the main DCC bus wires, but I have found them to be very unreliable. During my last layout I experimented with removing the insulation from the main DCC bus wires so that soldering the track feeder wires would be possible. This worked out really well. I am going to use the same method here. I stripped the insulation from the DCC wires with a utility knife. Next, I cut a number of MDF blocks, drilled two holes in them, pushed them onto the wires, and glued them down to the module's base. These blocks are only 1-1/8" tall so that they would not interfere with any future scenery plans. Obviously, the blocks are necessary to prevent the two wires from touching each other. Later on, when I am installing the track, all I have to do is find a convenient location on these wires to which to solder the track feeders. I will do the same thing for the accessories wires.
To complete the installation of the sub-roadbed, all that was left to do was to drill holes for the screws and attach it to the plywood blocks. I decided to use screws for two reasons. One, it makes it easy to remove the sub-roadbed should I want to change the track plan, and, two, it provides clamping force making sure that the sub-roadbed is flat and even. This photo show the sub-roadbed in place, but not yet installed.
I painted the sub-roadbed MDF with some latex paint to prevent any kind of future damage should water come in contact with it. I painted both the top surface and the sides. Again, the scenery filler pieces are just in there loose.
Initially, the base of the roadbed consisted of foam. To read more about my use of foam, see my Foam Roadbed article. This photo shows the foam installed on the MDF sub-roadbed.