在板坯下使用3“聚异构绝缘？

史蒂夫·维尔森|发布了能源效率和耐用性在December 17, 2015 02:24am

I am building a pretty good house next summer. I have an opportunity to purchase used 3″ faced polyiso (asking $25 a sheet). I am wondering if this would be a good fit for under my rat slab in my unvented crawl space and my attached garage slab. Both house and garage will have poured ICF walls in the foundation. Zone 7 northern MN. Looking to save a little money and buying used foam of course is a better environmental fit.

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Replies

GBA Editor

Martin Holladay|Dec 17, 2015 02:48pm|#1

史蒂夫，
Buying used rigid foam is a great idea. But you want to buy used EPS or used XPS, not polyiso, for use under a slab. Polyiso absorbs too much water to be used in contact with the ground.
Expert Member

Dana Dorsett|Dec 17, 2015 05:34pm|#2

他所说的是什么 - 从不在一个板块下，但是在基础墙壁的内侧很好，如果你把Polyiso的切开边缘放在板上。

如果你寻找它，通常会在廉价地回收屋顶eps。板块下的EPS具有漫长而成功的历史。有时也会回收XPS。从性能的角度来看，将重新使用的XPS是R4.2 /寸，而不是R5，尽管与氟氯化碳的一些预先蒙特尔议定书商品仍然可以在更高的R.
史蒂夫·维尔森|Dec 17, 2015 09:54pm|#3

我想，谢谢。很少看到在Mn中的任何回收的EPS或XPS。
Brad Hardie|Dec 18, 2015 07:36pm|#4

史蒂夫，

Check with InsulationDepot.com for EPS, XPS or Iso.
他们可以向您发货，甚至可以源于您附近的材料。我为我的项目买了一大吨，挽救了数千个。
史蒂夫·维尔森|Dec 22, 2015 02:01pm|#5

Thanks Brad, I will check with them.
Expert Member

Dana Dorsett|Dec 22, 2015 02:06pm|#6

Insulation Depot has changed their name to Nationwide Foam (but still headquartered at 703 Waverly, Framingham MA )

http://nationwidefoam.com/index.cfm.
史蒂夫·维尔森|Jan 31, 2016 11:50am|#7

谢谢达娜，价格已经下降到3英寸多自的价格为9美元，我的爬行空间地板将是一只脚左右的脚，我会用一个泄漏的水槽耗尽，我希望永远不会得到任何水。如果我放了，说1“XPS，那么Polyiso，那将是可以接受的吗？只是试图节省一小钱。
Charlie Sullivan|2016年1月31日12:32 PM|#8

Ooh, $9 for 3" sounds irresistible. But I still wouldn't use it below the slab--it might be OK in your configuration, but you are putting it where it really can't be replaced if it fails. How about two layers of exterior foam over a 2x4 wall?
Rick Miller|Jan 31, 2016 02:53pm|#9

史蒂夫，

在北部Mn，3英寸。Polyiso以9美元/张，我和查理一起。如果Polyiso形状良好，我现在就会买到它。我的房子在Mn中的两层3英寸。多元组超过2x6螺柱。我没有用5英寸的泡沫连接到铆钉的问题，我知道之前已经完成了6英寸。在那个价格上，你的（泡沫）价格为两层3英寸.Polyiso比我支付的两层2英寸的2英寸Polyiso所支付的价格便宜得多。
Brad Hardie|Jan 31, 2016 04:25pm|#10

史蒂夫，

That IS a very good price for poly-iso, if it's in good condition. Does that include shipping? Did you get that price from Nationwide Insulation? Just never, never, never use the poly-iso under a slab. You can get reclaimed EPS for less than $9/sheet, so why use poly-iso and chance it. If it gets wet - which it will....you mind as well just throw out your money. The XPS or EPS wouldn't stop water migration or vapor from getting into the poly-iso.
乔苏哈拉达|2016年1月31日08:18 PM|#11

If you are doing a vented roof, insulating the attic with cellulose I would also be inclined to put that up on my 2nd floor ceiling with taped seams, use furring strips, and attach my sheet rock below it, to get that R20 there before you place your attic cellulose at R40 or whatever you want. That is if you have nine foot ceilings upstairs and don't mind losing a few inches of ceiling height. Face the foil side towards the sheet rock. That is a lot of R for 9$...
Paul Kuenn|Jan 31, 2016 09:33pm|#12

Good day Steve!

I'd give this guy in Madison WI a call and make an offer:
https://madison.craigslist.org/mat/5404872209.html

and keep watching Craig's list. Two layers of 2" would work great as you can cover the seams. There's always good deals for EPS a day's drive away.
PK.