The smallest of my two layout rooms houses the depot of San Diego with Broadway Pier on right side and Old Town on the left side of the room.
On my previous layouts, due to unregular walls, I had to construct a frame to screw the backdrop on to. IN my current basement the walls are straight like all other rooms in the house. Building a subframe would only cost me precious real estate for my railroad.
So I figured out that gluing the 1/8 inch thick masonite sheets directly to the wall should also work. A trip to my local building supply store provided me with the mounting glues that I needed. These have an adherance factor of about 50 kilograms per square meter, which is more than sufficient because the boards are litterally leaning against the wall and not hanging from the ceiling.
Because I need all the available space for my rendering of the San Diego depot scene I did not cove the corners. There's no need for a curved corner on the right side of the room, because Broadway Avenue and the Pier are located next to it.
The left wall houses Consolidated Aircraft and the US Marine Base with Lindbergh Field. That's the place where the International Airport is today.
After all the masonite sheets were installed, I painted them sky blue. I did use a stronger blue color because lighter blues don't show enough on photographs.
The picture above shows my Broadway Pier extension. I tried to incorporate some office tools and desk under this part of the layout also.