Hi - Had the opportunity to crawl under the Fiber Stream
while the axles were being flipped. Noticed some loose bolts in the cross framing. I went upstairs and pulled the rug to find that carriage bolts with no washers had been used to fasten the plywood floor to the frame. Over time the bolt heads had cut through the flooring, in essence, the egg was floating on the frame.
I cut off the old bolts that had worked through and replaced them with new hardware, including fender washers.
This is an item to check for all those with older trailers with plywood floors. Fiber Stream
may be the only manufacturer to omit washers but it wouldn't hurt to check.