Replies

1. Expert Member
   Akos|Jul 18, 2021 08:57pm|#1

   Since you don't have any fluffy insulation on the inside, you can use pretty much any amount of exterior rigid. Zone 4 is not too cold, but it will still make a pretty big difference how cold the wall feels in the winter time.

   There is some thermal bridging from the screws but not enough to worry about. If you are not in a high wind area and since you are using light weight cladding, you don't need to go overboard, just enough to get the 2x nice and flat. 16" OC is pretty common for this.

   砌体螺钉进入砌块墙可能会很痛苦，我首先检查它们的保留程度。如果您能找到足够长的时间（通常是特殊订单），则锤子集混凝土销会容易得多。

1. 
   Timothy Godshall|Jul 19, 2021 06:14am|#4

   Thanks for the response - I'll see what I can find for fasteners.

2. 
   C L|Jul 19, 2021 08:46am|#5

   The above response makes sense, but should you also consider the following:
   - Is the 8" CMU really hollow?? Doesn't code require at least 25% of the cells have resteel and be filled with grout to hold the wall?
   - 如果所有细胞都真正是空心的，那么也许值得评估墙壁在投入更多资金之前是否可持续，以及是否应该首先花钱用于用resteel和填充的细胞稳定墙壁。
   - If the CMU does have resteel and filled cells as needed for structural stability
   a. Is the frequency of filled cells sufficient to use those for your fastening points?
   b. Is it worth considering foam filling the remaining cells for added insulation before you adhere the siding?

   Also, you mentioned installing vertical board/batten, fastened to horizontal 2x4 strapping that also holds the rigid foam under the strapping. The strapping will set the board and batten 1.5" in front of the foam to create an airspace behind the board and batten for handling of bulk water. But the horizontal strapping would trap that bulk water. I'm not sure how this issue is typically handled. I would be inclined to use treated lumber for the strapping, install the horizontal strapping at a slight angle, and stagger the horizontals such that wherever water enters, it has a way out and is not trapped by the strapping.

1. 
   Timothy Godshall|Jul 21, 2021 06:35am|#6

   谢谢您的想法。我不知道这些块是否完全填充和加强。我不确定代码对此有何评价，但我没有调查。我将拆除一堵墙，所以我想我会在那时发现并进行相应的进行。

   Good points on the handling of bulk water. I'll definitely cut the horizontal strapping at an angle and I will probably put some thin vertical furring strips behind the strapping so there is some air flow through the assembly.

2. 
   DCCONTRAIRARIAN|Jul 19, 2021 12:00am|#2

   如果您担心热桥梁，我会看那堵墙的顶部和底部。它们在建筑信封内吗？

1. 
   Timothy Godshall|Jul 19, 2021 06:09am|#3

   Good point about the bigger areas of thermal bridging. The top has attic insulation covering it, but the bottom goes right down to the ground so that will remain a major thermal bridge.