关于屋面选择###屋面选择和建筑规范屋顶瓦粘土和混凝土瓦屋顶可以安装在坚实的护套上或倾斜2.5/12或更高的屋顶间隔的护套板上。小于4/12的屋顶需要双层衬垫(905.3.3.1);屋顶斜度为4/12或更高，需要一层(905.3.3.2)。瓦片的连接方式因气候条件、屋面坡度、衬垫系统和瓦片类型而异。关于正确的附件方法，请参考IRC第905.3.7节和表905.3.7。在墙壁和垂直穿透处应设置闪水和防闪水。山谷闪光必须至少26号“W”型材，G90镀锌板和从山谷中心线两个方向延伸11英寸(905.3.8)。Slate Slate在2006年IRC第905.6节中被涵盖。石板瓦必须用两颗钉子安装在至少4/12节距(905.6.2)的实心护套屋顶上，下面是ASTM D 226, Type 1衬垫(905.6.3)。有冰坝历史的屋顶区域必须有两层粘合在一起的衬垫，或自粘的沥青膜，从屋顶边缘延伸到建筑外墙线之外24英寸。 Head lap requirements vary with roof pitch and can be found in Table 905.6.5. The minimum standard for valley flashing is 15-inch, G90 galvanized steel of .0179-inch thickness (905.6.6). Asphalt roof shingles Asphalt shingles (Section 905) must be installed on solid sheathed roofs of at least 2/12 pitch with 12-gauge roofing nails long enough to go through the shingle and penetrate the roof deck 3/4 of an inch. Roofs under 4/12 pitch require two layers of underlayment; roofs 4/12 and steeper require one layer. Roof areas with a history of ice damming must have two layers of underlayment cemented together or a self-adhering, bituminous membrane extending from the roof edge to 24 inches…