This is a 1/2 inch PVC pipe hanger, made to hold two pipes spaced so pigeons can not fly between them and into the top of the loft.
I mount mine on a 1x2 furrowing strip then tack the strip up. On second strip, mount exact same spacing of mounts. then slide pvc pipe into tacked side, then untacked, going back and forth until full ceiling is made. Then tack the untacked side up.
Since the PCV pip can spin, pigeons can not get a grip and can not force their way thru into the "attic" space of a normal garden shed. This allows for a cleaner coop, and you can mount fans without worry of pigeon flying into it.
Makes catching pigeons easier too by keeping them where you want them. Current spacing is about 2 inches and made for 1/2 in pvc pipe.
At 35% infill it is pretty strong, print one, try to break it, change infill up or down.