For the Johnson County DHS Parking Garage, the last structure needed for the Iowa City section of The Hills Line, I decided to attack this project as a series of sub-assemblies. The first segment was the parking deck itself, since it was a relatively straightforward process to design and construct.
The concrete portions were made from .040 styrene. I’m still on my original 4×8 sheet that I purchased from a commercial plastics shop, which is a testament to buying full-sized pieces instead of the smaller, and often more expensive hobby sizes. However my local supplier has closed up, so hopefully I can locate another source nearby. I cut two identical 15 inch by 8 inch slabs for both floors of the garage, notching out the northeast corner for the elevator shaft and stairwell.
For the internal supports I used balsa wood since it’s inexpensive, cuts easy, and comes in a variety of available sizes. Balsa also has the advantage of simulating a rough concrete texture once painted. The pieces were cut to a consistent length with my NorthWest Short Line Chopper.
The supports were attached to the top deck with hot glue. Additional pieces were secured underneath the top deck to stabilize the entire structure and prevent undue flexing. Each support was squared and plumbed to the floor, the roof, and each other. Fortunately hot glue goes on quick and sets up even quicker, so it’s simple to finish quickly.
More styrene was cut for the exterior walls and attached again using hot glue. The bottom strip is actually that narrow on the prototype, since it’ll be buried in the grass when finished. I lightly scored the expansion joints on the face of walls with a scribe tool.
Gaps and seams were filled with modeler’s putty, then the entire structure was painted with Testors Flat Light Aircraft Gray. I’m holding off on weathering and striping until the end of the project. Up next is the acrylic stairwell and elevator shaft.