Yeah, my kit had no provisions for sheeting the bottom center section nor instructions to do so. Since it was my first kit, I didn't know any better. That's something I would do differently if I built another one. The included fiberglass wasn't long enough to go all the way around, either, so you'd need to source a bit more. Besides the added strength, it would make the wings easier to handle without worry of damaging the center section with your fingers.