I have set paper size (tabloid) and margins (3/4" left, 1/2" right/top/bot) in layout and printer settings, but when I print the edges of the plans are cut off. I’m wondering if this is a printer thing or am I missing something in layout?
Hard to say with no more information than you’ve provided. Share the LayOut file so we can see exactly what you’ve set up.
OK. I’m not sure how to do that… 
If the file is 16 Mb or less drag the LayOut file into a reply. Otherwise upload it to DropBox or We Transfer and share the link.
So have you exported a PDF and printed that? What do you get if you print this PDF? Do you have a printer that can handle 11x17 paper?
BCJ CEILING PLANS.pdf (2.3 MB)
On another note, I see you’ve modified the Camera properties in LayOut. It would be better if you set the camera to Parallel Projection for your scenes in SketchUp and not modify the camera properties in LayOut.
I I set the scenes to Parallel Projection in your SketchUp model and updated the viewports which I set to common scales. You’ll need to make a few adjusstments of the labels and those heavy blue lines but that should be straightforward.I also purged a whole lot of unused materials from your model and the unused titleblock stuff that came with the LayOut template you started from.
BCJ CEILING PLANS.layout (808.0 KB)
Actually I was just printing straight from layout. I did notice when I sent the PDF file to someone it didn’t cut the edges off. I didn’t think to print from there though. So it sounds like it is better to send to a PDF to print correctly instead of printing from layout.
I will start using parallel projection and play around with the scales you mentioned. Thank you for the help!