今天有个朋友打电话给我，想在他的褐砂石房子里添一间新房间。他在顶楼有一块闲置的地方，他想在那里建一个酒窖。顶楼有个酒窖吗?这肯定不是一个理想的地点。但只是为了好玩，让我们假设他没有地板负载问题，他可以充分绝缘和密封墙壁和地板。屋顶呢?我说过这个空间是在没有通风的平屋顶下面吗?所以在外面干燥是不可能的。我认为最大的问题是外壳。他不能让一个寒冷的屋顶接触到50度左右的空气，湿度50%或更高。 So first step is to put ccSP on the sheathing, let’s say 5 inches. I believe he has 2×10 rafters, so say he puts 4.25 of dense pack in to fill the bays and then adds a smart vapor retarder. Not ideal, and a few R short of code, but this is not an ideal situation to start with. While this assembly may be vapor open to the inside, it really isn’t because the humidity levels will be high in the cellar. Another option is to make a vapor sandwich, yes I said vapor sandwich, and hope for the best. Same stack-up, except foil-faced polyiso inboard which will kill the bridging through the studs and hopefully keep all the vapor in the cellar. He could add some wireless humidity sensors to see when he is going to have to replace the roof, maybe just a few years down the road. A third option would be to add a dropped ceiling in the cellar. So in the rafter bays he would have ccSP, DP, smart vapor retarder, and maybe an inch of Comfortboard to meet code. Then drop the cellar ceiling (he has 10′ of headroom to work with). Vent the area between the roof and the dropped ceiling into the adjacent areas of top floor. He could use 2×4’s for the dropped ceiling, add dense pack, 3 inches of foil faced Polyiso and he has an air and vapor tight wine cellar ceiling with an r-value of around 30. Assuming he can actually vent the space between the top of the cellar ceiling and the bottom of the roof into the rest of the house, he would have a way for both assemblies to dry if needed. Do you think this would work.

谢谢，

乔纳森