New Benroy Build Finally Underway

Hey Guys,
I headed out to Home Depot tonight with my list of materials and bought all the lumber for the floor, Ouside Walls, and Roof Spars. While I was gone to the big orange box, my correct Left Rear Rail for my trailer showed up at my doorstep. I can now begin finishing assembly of my trailer and begin building my floor tonight. I chose took everyone's advice and just got the cheaper lumber for all the floor framing and roof spars. I am ripping 2x4's in half for the floor frame and using 1x2 pine for spars. While I was at Home Depot, I also bought the rest of the tools that I needed so I got a Ridgid 3"x21" Belt Sander, Right Angle Drill Attachment, and Vermont American Poket Hole Jig for joining the cabinetry.
One MORE dumb question before I get started. I don't know if I asked this before but here goes, I di not cut my Red Trailer cross members down my 2" but I am going to build where the walls hang over the sides and cover the trailer. Do I need to add 2" to all my cross members like floor, spars, and roof sheeting? Will this clear the wheel ok? Am I looking at cutting my floor plywood to 60"? When this is answered I am ready to get into my build. Thanks Guys.
I headed out to Home Depot tonight with my list of materials and bought all the lumber for the floor, Ouside Walls, and Roof Spars. While I was gone to the big orange box, my correct Left Rear Rail for my trailer showed up at my doorstep. I can now begin finishing assembly of my trailer and begin building my floor tonight. I chose took everyone's advice and just got the cheaper lumber for all the floor framing and roof spars. I am ripping 2x4's in half for the floor frame and using 1x2 pine for spars. While I was at Home Depot, I also bought the rest of the tools that I needed so I got a Ridgid 3"x21" Belt Sander, Right Angle Drill Attachment, and Vermont American Poket Hole Jig for joining the cabinetry.
One MORE dumb question before I get started. I don't know if I asked this before but here goes, I di not cut my Red Trailer cross members down my 2" but I am going to build where the walls hang over the sides and cover the trailer. Do I need to add 2" to all my cross members like floor, spars, and roof sheeting? Will this clear the wheel ok? Am I looking at cutting my floor plywood to 60"? When this is answered I am ready to get into my build. Thanks Guys.