A bathing vessel has a bottom, and a drain disposed in the bottom adjacent a blended area that is disposed between the side wall and the bottom. The side wall, the bottom wall, and the blended area are made of a first layer of rigid polyurethane material and a second layer of capping material attached to said first layer. A ratio of a density of the polyurethane backing adjacent the drain to a thickness of polyurethane backing is between 1-80:1. The side wall, the blended area and the bottom wall flex to absorb loads adjacent the drain.