I was able to get the shed deck complete this evening. The photo shows the joists before putting the plywood down.
These joists are made from the materials of the old shed: foundation 4x4's, some of the 6' studs, and all of the 2x4 rafters. Based on the span requirements (see previous posts), I decided to double up all the joists.
Most of the joists are on 2' centers, except as shown in the lower corner. This is where the lawn tractor will be parked, so I put them on 16" centers for extra support.
The photo above shows the joists being shimmed with pieces of asphalt shingle. I have noticed that pressure treated wood tends to be a bit larger that KD studs. I did this to bring everything up to the same height for the plywood.
Here is the deck with the floor installed. One of the nice things about a 12x16 shed is that the materials fit nicely with a minimum of cutting and waste.
The next step is to frame and raise the walls.