Insulation question
I have an apartment want to add insulation from the exterior.
It is a block building 1950’s vintage. Walls in the inside are stripped with 3/4 furring strip. Insulated with 3/4″ fiberglass with vapor barrier on inside. Finished inside with plastered walls.
I am thinking of adding foam sheet insulation to the outside of the building. I do not want to trap in moisture and cause mold problems. .
What is the proper way to do this. I do my own work. If anyone can guide me in the right direction I would appreciate it.
Thank You,
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Replies
Charles,
隔离这种墙的最佳方法是在外部安装连续的层（或两层）刚性泡沫。墙壁可以用合成灰泥（称为EIFS的系统）覆盖，也可以安装16英寸O.C.的垂直毛发条，以准备几乎任何形式的壁板。
大多数建筑代码将这种类型的墙分类为“大墙”。这种类型的壁的最小R值要求从气候区域1中的R-3到气候区7和8中的R-19。
With the vapor barrier (I'm assuming this is polyethylene sheeting?) on the interior side of the interior furring you have to be more careful about what you put on the outside, in which case many EIFS products are too vapor retardent.
If the vapor barrier is kraft paper or rosin paper, that's not a problem, but if it's polyethylene or foil it's an issue. If the vapor barrier were between the block and furring it would also not be a problem. But it sounds like you have:
外部油漆|混凝土块|毛茸茸和玻璃纤维|蒸气屏障|石膏上篮|内部油漆
To preserve at least some outward drying capacity you can go with up to 3" of unfaced Type-II EPS (R12.5-ish) behind rainscreened conventional siding. At 3" that would give you about 1 perm vapor retardency between the interior furring & exterior, which is about the limit of how low you can safely go.
使用XPS，您必须在约1-1.5“。
No foam with foil or plastic facers would be advisable.
I would like to thank you gents for the information you have both provided.
我应该包含的最后一个问题。如果我搭配泡沫片，我可以使用密集的泡沫，还是应该在线上使用的东西，我称之为更开放的牢房泡沫（白色的泡沫片，用刀切时会碎成小块）
The really crumbly EPS is Type-I (1.0lbs per cubic foot nominal density). It is more vapor open, but not very rugged. It's often sold with facers to enhance it's handling tolerance, but the facers reduce the vapor retardency to near zero. The right compromize of ruggedness to vapor openness is Type-II EPS (1.5lbs nominal density). You can break it, but it doesn't fall apart easily. Most insulated concrete forms are made fromType-II EPS- it can take quite a bit of beating, unlike it's lighter-duty cousins.
BASF NeoPor is a higher-performance grahpite loaded Type-II EPS, but it's hard to find, and it's not super-cheap. There are many EPS vendors large & small, and you can usually find a local vendor or manufacturer dealing in Type-II sheet goods if you look for it. You won't find it at box-store home centers- try distributors who deal primarily with the construction contractors, and be specific about the density, thickness and un-faced aspects.
Even though the macroscopic bead structure of EPS gives it some interstitial spaces that give it a higher vapor permeance, it is still a closed cell product at the microscopic level, even at lower density.