I'm going to be moving into a new house that has a finished garage with a high ceiling. I want to build a loft in the garage for storage. There are plenty of online span calculators that should help me figure out the joist dimensions and spacing, but I'm not sure how to support the whole thing.
I'd like to avoid opening the walls, unless there's a big benefit to doing that. The loft will be in the center of the garage, touching two walls on opposite sides (17.5 feet apart). I'm thinking of using 4x4 posts along the walls to support ledger boards, with no posts in the middle of the garage.
I don't know how many posts to use, what size ledger boards to use, or the size and type of fasteners to use. Is there an easy way to calculate all that?
What resources can you suggest that would help me learn how to design the loft correctly? Are there any free or inexpensive design tools I could use to draw up plans for getting a permit?