As an alternative to tar felt, sheet zinc, aluminium or copper is often used in high-class work as a finishing to a reinforced roof slab, but very seldom to timber flat roof construction.

• 除采用油毡防水之外,在钢筋混凝土板平屋盖的豪华建筑中,为装饰需要,还常常采用薄锌板、薄铝板或薄铜板代替油毡,但很少用于木板平屋顶结构。