We have a 5 foot wide shower. We would like it without a curb, our contractor says no. Our plumber says he has seen them and there is a "trick". Anyone know the trick? It is not the plastic or rubber overlayment to the joists. We cannot cut into the joists nor can we raise the floor. We are trying to go without a door, or put a door to the floor without a curb. Neither is recommended by our contractor. Additionally if extend out a bit farther (bathroom is 5 x 16, we may add a tub thus making that portion a wet room. Any thoughts? Thanks!