你好,
我住在加拿大不列颠哥伦比亚省，我的屋顶上有2-3英尺厚的雪。我最近买了一栋房子。这是一个盐盒风格的房子，几乎没有悬挑。我们接管了房子，立即拆除了所有的干墙，并彻底翻修了整个房子。将所有外部2×6墙升级为r22玻璃纤维隔热层，带有6mm蒸汽屏障。房子前面长长的倾斜部分是一个大教堂设计。2×10椽子和2×2绑在椽子底部。我想椽子上有一个r30在空中留下一个1。我注意到，前16英尺的胶合板是好的，但进一步它是黑色的。所以我知道有通风问题。 I found where the cathedral ceiling connected wth the attic and the attic insulation was blocking the air flow. I knew the sheathing had to be replaced but I still installed continuos baffles from the the front of the house and into the attic for the time being. Reinstalled the insulation and 6mil vapour barrier paying close attention to air sealing. The first winter came and I found a large melting spot across the entire roof where the attic and cathedral ceiling met. Also a large ice dam on the front of my house. So in the spring I brought in a insulation guy. He said the main problem was the wall where the attic trusses and the rafters meet wasn’t insulated. So we dense packed that wall and upgraded the attic insulation from r 20 to 60. He also said he wanted to dense pack the entire cathedral part of the ceiling. No air space , no soffits just use gable vents in the attic. We did not do that I did not agree with that. So the second winter came. The frost line was a bit better but not perfect and still a huge ice dam.
这个夏天是时候做屋顶了。我的计划是拆除护套和绝缘材料。扩展的椽子2英尺/挂前,安装多屏画面等等softit发泄,replywood屋顶和致密包整个大教堂天花板(10和3/4“椽湾应该r40),然后用2×4带屋顶是平的,封面加盖胶合板1 1/2 "发泄从前面到阁楼上。我还计划使用通风滴水边缘或边缘通风系统，从风口在阁楼的一边，以帮助从那一边的排气。阁楼一侧不像前面那样受冰大明之苦。也盖上我的山墙通风口，安装木瓦通风口2个连续的山脊通风口。
从我的阅读这个屋顶设计，无论我做什么，因为雪负荷和温度波动(从+ 3到-30摄氏度的任何地方)，我可能无法防止冰大明。
我的问题是我的方向对吗?我应该考虑做点别的吗?我觉得自己很幸运，在一座35年前建造的教堂的屋顶上，有将近11英寸的椽子可以玩。我应该听绝缘pro和密集包没有通风，只是依靠我的山墙通风为阁楼?我已经从侧面附上了我房子的蓝图。谢谢