I have a 2016 201bhxl with the black tarp like material on the underside. I have noticed that it has torn lengthwise, along one of the frame crossmembers. I understand the general idea of repairing it by splicing in a new section with tape or spray adhesive. It apears the trailer is built with the black material then set on the frame. I'm not seeing a good way to get the new material between the floor joists and frame cross member to complete the repair.
The tear is right in the middle of the frame crossmember. I'm thinking it may be best to attach the new sections of material directly to the frame crossmember, instead of trying to go over it to span the opening.