EPS, PolyIso, or Double Stud Wall
我正在研究我的研究，在这三种选择之间具有相当的争议。
Zone 5B – SO I have to worry about hot summers and freezing winters.
In a couple of questions I posted here I learned that EPS is more of the favored child around here while XPS is considered more costly (Agreed) and poorer performance in cool temperatures (I don’t know, just going by what I heard)
当他们居住在一个密集的地区时，我没有大多数人的选择。我住在一个乡村小镇所以当我增加拖运或运输的成本时，通过找到更多本地或回收产品的成本节省。
I was going to opt for 2″ of EPS outside my 2×6 Wall with R19 Fiberglass (Or R21 Mineral Wool)
我所在地区提供的产品：
$ 7.99 R4 1“x 4'x 8'扩展聚苯乙烯绝缘
$ 15.19欧文斯康宁泡沫250 1“x 4”x 8'R-5刚性泡沫绝缘
$30.99 JM CI Max¯ Silver 1″ x 4′ x 8′ R-6 Polyiso Rigid Foam Insulation
eps非常脆弱，它很容易打破，用白色珠子弄乱。XPS必须更加僵硬。多自是最刚性的，并用铝面保护。
房屋尺寸是44英寸x 30'd = 148线脚@ 9'墙覆盖+山墙末端=大约1500平方英尺，覆盖泡沫。
This calculates out to roughly 50 sheets, or 100 sheets after I overlap the first row to get 2″ total.
EPS: $800 for total of R-8
XPS: $1,600 for total of R-10
Polyiso：R-12总数为3,100美元
我想,也许我应该ditch the foam idea and spend the savings on some interior 2×4’s and make my interior cavity be 10″ wide for cellulose. I would want to have my windows be outties for simplicity and because interior trim is no problem.
What am I overlooking here?
答复
Polyiso does worse in cold weather; EPS and XPS both do better. Over time, XPS's R-value slowly falls to barely higher than that of EPS. Not worth it long-term unless its mechanical properties are otherwise desirable.
At those prices, EPS is a no-brainer, and you should go thicker if you have the option to. R-12 EPS would be literally half the price of the polyiso for the same on-paper R-value.
Furring out your 2x6s with 2x4s to create 10" cavities is not a worthwhile endeavor ; the studs will still be causing thermal bridging. If you don't want to use foam, your best option is a double-stud wall with each side made out of cheap 2x4s and filled with cheap cellulose. A 10" double-stud wall full of cellulose thermally braking the studs is an inexpensive great performer.
With outie windows, you'd apply your housewrap over the foam. The thicker the foam, the more of a problem it becomes to adequately attach the window and the housewrap. A double-stud wall simplifies this detailing; you just build a plywood box right through the whole wall nail the housewrap right over the exposed sheathing. Some people worry about cold sheathing collecting condensation with double-stud walls; I'd use plywood rather than OSB for peace of mind. And use a ventilated rainscreen gap made of vertical furring strips over the housewrapped sheathing. Fasten your cladding to that.
Long-term, the double-stud wall may be more resistant to termites. They love to tunnel in foam, but dislike the borates in borate-treated cellulose.
Nathaniel，如果我有专业知识和时间，我不介意增加更多泡沫。我的建筑时间紧张，以满足银行法规。我想什么2"挂在窗户时会变得麻烦，因为你提到它成为一个问题。
在WRB细节方面，双螺柱墙似乎更传统。在OSB和OSB上提出胶合板的想法*仍然*using firing strips sounds like a compromise not worth the hassle if I would already be doing that if I used rigid foam exterior, therefor not gaining much in terms of labor time.
Do you think my assessment of "anything over 2" is troublesome" is accurate?
我是唯一一个发现eps泡沫的人在确保它不会破裂的情况下，尤其是在使用1“纸张与2时”。
易碎的EPS可能是I型（每个立方英尺的1.0磅标称密度）。II型EPS（1.5磅密度）对处理更强大，并标记为R4.15或R4.2 @ 1“而不是R3.9或R4。通常比任何给定R-的XPS比XPS更便宜25-30％价值。
In a zone 5B location, a layer of 1" polyiso next to the structural sheathing with 1" EPS between the polyiso and siding will give better mid-winter performance than 2" of polyiso. EPS gains performance when the average temp through the foam is lower, whereas polyiso performance falls off a cliff when the average temp through the polyiso layer is under 40F. An inch of Type-II EPS as the outermost layer would be hitting north of R4.7 during the coldest weather, whereas if it were polyiso it would be somewhere around R3. By putting the EPS on the exterior and an inch of polyiso in-between you'll get a fairly stable mid-winter performance of about R10, a performance level that will not change much over decades of time.
在最寒冷的时间内至少在前几年的最冷的时间内将在大约R11上进行大约R11，但由于它失去了几十年来的气候损坏的吹风剂，最终会降至约R9-9.5，与EPS相同相同的密度。
R19 Batts来自饥饿 - 它们是销售的垃圾绝缘产品之一。R19作为R13玻璃纤维BATT具有相同的每平方英尺，（毫不奇怪）在R13压缩到3.5“时，在R13上执行。当压缩到5.5”时，根据制造商，他们仅在R18执行。自己的压缩图表。（它们是根据其制造的阁楼的测试性能达到约6“。）R23摇滚羊毛非常好的东西，如R21”大教堂天花板“高密度玻璃纤维蝙蝠，其中任何一个都将在安装时按标记的R执行2x6框架。R19S在辐射车间下绝缘（下面有条件下面），但墙壁绝缘的借口不佳。
在2x6纤维填充壁外部的R10-ISH泡沫的“全壁”性能在热桥接中进行了约R23-R25时进入R23-R25。具有10个“厚纤维素（11”厚壁的双2x4壁（一个11英寸的厚壁，从挡板涂料，12英寸从底板涂料到内墙板）将进入R28-30，具体取决于螺柱间距和底部的框架细节顶板和窗户/门框等。
嗯，我打赌这就是我得到了搞笑的原因看起来当我告诉人们EPS是一个比XPS更好的产品，他们被用来的类型 - 我崩溃了很多产品:)我会看看他们是否可以特殊订单类型-II反而。
我没有考虑在外面的eps上面的聚会。但是，如果冬季的Poly的R值减少，我只有2英寸的刚性外观，我想知道我是否会面临绝缘外部造成的“冷鞘”问题。
The R23 mineral wool is something I will consider. It appears to be higher priced. It costs me $1.27 per sq ft compared to $0.59 per square foot for R21 CertainTeed Fiberglass.
随着您的“全墙”评价，您将提到R23-R25，计算热桥接。泡沫不会消灭热桥接，就像双螺柱墙一样多？