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Building Flats

Using a Trackmobile, the crew at Imerys moves cars to the loading area. This large prototype facility is modeled using building flats to reduce the overall foot print, but still be large enough to look like it is rail served.

Space on a model railroad is always at a premium. One way to save precious space is by using building flats for our industries and other structures. Large industrial structures can take up a lot of space, but we really only need to model the rail side portion of the building, that’s where a building flat can be ideal. By reducing the buildings depth to only a few inches we can still represent a large rail serviced industry.

On my GNRR layout, a majority of my structures are building flats. The buildings are large enough to realistically be rail served, but only take up a few square inches because they are modeled as flats. In my opinion, for a building flat to look good it should be no less than 1 inch deep. When building flats are thinner than that, the transition between the building and the backdrop begins to look strange. I also use trees, or other structures to help hide the transition between the structure and the back drop.

One issue that comes up when you are constructing a building flat is how to brace the walls so that they are strong enough to support the roof and not warp. On my Capitol building materials structure I used extruded foam insulation board to create a “core” and then glued the wall sections to the foam using a foam safe adhesive.

While only a few inch deep, this O scale structure replicates the look of the prototype facility.

Recently I scratch built a large warehouse for a friend of mine in O scale. The finished structure was over 6 feet long and I decided that I needed another material other than extruded foam to use as the core. I chose to use PVC wood that comes in standard dimensional lumber lengths, and does not shrink or warp. The material is a little more expensive than regular wood, but the stability is far superior to wood. The material can be cut and worked with the same tools you use for wood, and can be found at most home improvement stores in the lumber aisle.

The PVC core is assembled and the area for the roll up doors has been carved out with a router.

The warehouse structure represents a tilt-slab style of building, one where the walls are poured in a form and then erected using a crane. I used plastic panels that my friend purchased just for this structure for the walls. I arranged the panels for the number of doors and length needed to accommodate 5 boxcars. Once I had the dimensions of the structure calculated, I built the core using the PVC wood. One end of the structure had a bump out so that was framed out with the PVC wood. I used a router to carve out the PVC wood where the roll up doors would be located. This allowed the doors to sit flush behind the wall sections. After carving out the door areas, I attached the loading dock which was made from one piece of PVC wood, to the main core portion using adhesive and screws. This created an “L” assembly which helped keep the main core straight. I also attached the bump out portion to the main base section and the loading dock.

The wall panels were attached to the PVC core with adhesive caulk after painting and installing the overhead doors. Trim was added around the door openings and the structure was painted. Next, I added the beams for the awning by drilling into the walls and PVC core. This worked out great as the PVC wood added the support needed for the ends of the cantilevered beams. The awning was made from two long pieces of styrene and trim added along the outer edge. Piano wire was used for the awning support rods. Some final painting and detailing, and the structure was ready to go to my friend’s layout. It really is an impressive structure, especially in O scale.

I hope this blog has given you some ideas for your next building flat structure project. Until next time, stay safe and keep model railroading.

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