I want to start by thanking everyone that has responded to my many questions. My layout would not be where it is today if it were not for the advice and suggestions from you folks. It is greatly appreciated. I am at a point with expanding my 4' X 8' HO layout to where I am buying the building materials for the 2' X 8' extension. The plan is to have the 2' length of the 2' X 8' section attach to the 8' length of the current 4' X 8' layout. This will make it an "L" shaped layout. I hope that description makes sense. I am interested in hearing how I should connect the new 2' X 8' section to the existing 4' X 8' section. And just to make this a bit more complicated... the existing 4' X 8' is on casters and the new 2' X 8' section will be on casters as well. They are locking casters so that I can "lock/shim/level" as needed. I do not plan on "disconnecting" the two sections from each other until there is an emergency. Translation: The two sections will only be disconnected, moved, and reconnected when my wife tells me I have to move the layout to another section of the basement.