Hello Well, since I had a whole bunch of leftover plywood from the shed, I finally had a chance to use it. I did sped $15.00 for 8 - 2x3s to use for runners. I nailed them to the truss and then screwed down the plywood after cutting to size. Each runner is 29 inches long with 40 Deg cuts on each end. The shelf is 29 x 22-1/8 to fit between the trusts. I made 12 shelfs so far! Something to put the suit cases on! LOL See pics below. Click to enlarge.