I want two workshop buildings, one for 00 and one for H0. I started with the 00 one, using a kit cut down to nearer H0 proportions but I am not happy with it as a model and I hope to build a replacement for H0 one day. So the base needs to serve two buildings.
I started by assembling the four walls of the 00 building, and then glued down some 5 mm foam board to fit snugly inside these walls. This thickness fits just below the tops of the rails. The two strips of thick styrene here are to make the flangeways when I fill in the gaps. There is an isolating section here for DC operation, hence the two sleepers close together.
Then Milliput to fill in the gaps beside the rails. Milliput uses water as a lubricant, and this tends to dissolve low-grade foam board. A different filler might be better:
The ground surface is Scalescenes 'concrete' texture printed onto thick paper. The yellow lines are microstrip painted yellow, I know this is a bit crude / old-fashioned but the thickness does not show from normal viewing angles. The steps in the base nearest the camera are for a fire exit:
The inspection pit is from a Peco one for code 100 rail, tho' the rail here is code 75. Some Roco wheel flanges will bottom out on this, but I don't think they will ever need to run into the building. At the moment, the inspection pit does not have a floor - only the two sides. I put these in when I laid the track. I have an idea to fix the floor of the pit 1 mm or so below the sides, to allow for some pit lighting but I've not really thought this trough yet. This will let me make the pit a bit deeper than the Peco model, which seems a bit shallow, even for H0.
The ground surface outside the front of the building is 3 mm cork, chamfered and curved to match the track underlay. I am using up N gauge strips from years ago here:
The turnout in the foreground is overhanging one edge of its cork bed because I laid the cork for Peco, and then decided to try hand built track using a geometry nearer to scale.