我们刚从澳大利亚的墨尔本生活。作为参考，我们的气候区是CFB（温带，没有干旱季节和温暖的夏季）。年度HDD（Farenheit，基础65度）为2,838度。年CDD为450度。它很少低于冰点温度。

We’re renovating our house, and I’m stuck with what to do with our roof. It’s a VERY flat metal roof. By design the pitch is 0.5 to 0.8 degrees. That’s not a typo. Current structure is 6 inch hardwood joists at 16” centres, that function as both ceiling and roof joists. Original T and G timber lined ceilings from the 1960’s below, battens above to give it its minimal fall, and then the metal cladding above. There is some aluminium sarking below but it’s in pretty bad shape. So technically, a ventilated roof, but probably ineffective.

实际上，我们正在尝试使热性能正常，并且不要用水蒸气来燃烧桥梁。由于其他Arhchitectutal细节，栏杆墙等，我们可以建造屋顶的高度有很大的限制。

currently, I’m thinking (from inside to outside) 6 inches of glass wool insulation between joists, battens to increase the fall to around 2 degrees (about max we can achieve. This is definitely doable from a metal clad roof specification point of view. Often done in Australia), a vapor open WRB (ie: Pro Clima Mento Plus), ventilating battens above, then metal cladding. Hopefully this will provide a drainage plane to deal with condensation on the underside of the metal, even if it’s pretty ineffective at ventilating (no stack effect).

这所房子永远不会是一个出色的表演者，也不会是高度密封的（混凝土砌体单元墙壁上没有密封的层。我认为Mento Plus可以用作屋顶的气密层，更多地保护木屋屋顶从水分而不是从热性能的角度实现任何严重的气密性的结构。

Rigid roof sheathing below metal clad roofs are almost never used in Australia (usually screwed onto battens, but given the very flat roof (even at 2 degrees), I think it’s a must to support the flexible WRB and stop it ponding. I’d rather not go the vapour impermeable foam sheathing route, which will commit me to a warm roof sheathing approach, which I don’t think we will achieve with our height limitations.

是否有人对我们可以用来支持WRB的明智的渗透性刚性/结构屋顶护套得到了建议？OSB和胶合板的蒸气渗透性似乎是大多数本地供应商所未知的。我担心无法在两个方向上干燥的护套，并从WRB下方的水蒸气积聚中潮湿。

另外，人们是否偏爱WRB上方的垂直与水平板条，或者对某些“开放”塑料板条的看法，以便让冷凝水滴落在WRB上以不受阻碍地排出WRB？

提前致谢。

乔治