班長,梁兄,Professional Engineer還有哪位高手,flat 屋頂的Rolled roofing 基本上快到壽命了, 是塗那個啥 coating , 修修補補延長生命, 還是全部換掉?
如果換, 哪種材料比較好? (這個1997年的書是這樣說的,
The four most common types of flat roof systems, listed in order of increasing durability and cost, are: roll asphalt, single-ply membrane, multiple-ply or built-up, and flat-seamed metal. They range in cost from as low as $2 per square foot for roll asphalt or single-ply roofing applied over an existing roof to $20 per square foot or more for new metal roofs.)
多謝,