Replies

1. Expert Member
   Michael Maines|Mar 27, 2017 09:01pm|#1

   Joshua, for most situations, type 2 if fine for sub-slab use. Its compressive strength is similar to sandy soil. A 4" slab contributes about 50 psf of load; add a 40lb live load and you're still below 1 pound per square inch. The compression curve for foam plastic is usually pretty straight, so insulation rated at 15 psi would compress somewhere in the neighborhood of 0.015 of its thickness. For 3" foam, that's less than 1/16". Not enough to worry about.

   9型更好的是支持屋顶上层载荷的区域，例如下面的地下。

2. GBA Editor
   马丁·霍拉迪（Martin Holladay）|Mar 28, 2017 05:59am|#2

   迈克尔，
   Thanks for your very helpful comment. I've decided to edit my article,“Choosing Rigid Foam,”to include your advice.

   -- Martin Holladay

3. 
   斯蒂芬·希希（Stephen Sheehy）|2017年3月28日上午08:30|#3

   Joshua: Remember to look for reclaimed foam.

4. Expert Member
   Dana Dorsett|Mar 28, 2017 09:33am|#4

   For almost all residential slab applications Type-II EPS is fine. But under footings or load bearing posts it may need to be something denser. EPS insulated concrete forms (ICF) are all Type-II, and it is sometimes quicker / easier / cheaper to pour the stemwalls in ICFs, unless you find a source for used roofing EPS, which is almost always Type-Il, to enable a "walkable" membrane roof. Type-I is too easy damager or to leave permanent boot tracks in, even though it's still strong enough once the slab is installed. With Type-II you can usually walk on the foam prior to the pour without screwing it up (unless you are a 300lb guy carrying 150lbs of rebar on one shoulder.)

   商业建筑重新屋顶/拆除的收回EPS相当普遍且便宜，通常为1/4-1/3，从打捞服装和泡沫回收商中获得的Virgin Stock Goods的成本。它在那里，您只需要搜索一点即可。尝试搜索您的本地craigslist查看：刚性绝缘，例如：

   https://boston.craigslist.org/search/sss?query=rigid+Insulation

   https://denver.craigslist.org/search/sss?query=rigid+insulation

   https://sacramento.craigslist.org/search/sss?query=rigid+insulation

1. 
   Johanna Carr|6月7日，2020年11:57 AM|#9

   Dana, you mention using reclaimed foam. How about factory seconds where the boards are not of uniform density? Some areas are very firm while others are spongey. Will those areas compress immediately as the slab is poured or will it result in later cracking from uneven settling?

5. 
   乔恩·R|Mar 28, 2017 09:46am|#5

   For higher loads, see here:

   http://www2.owenscorning.com/worldwide/admin/tempupload/pdf.077_HighDensity_E_1.pdf

6. 
   Joshua Greisen|Mar 28, 2017 10:14am|#6

   感谢您提供的所有有用信息。我环顾四周，寻找了II型，在华盛顿州地区没有发现任何东西。有人有很好的来源吗？

7. Expert Member
   Dana Dorsett|2017年3月28日下午4:48|#7

   华盛顿州涵盖了很多领域 - 您能更具体吗？（如果您住在奥林匹亚，您并不想从斯波坎运送它，但是Portand或Bellingham并非没有问题。）

   Nationwide Foam ships anywhere (for a price based on distance from the depot), and has a depot within a day's drive of any WA location.

   http://nationwidefoam.com/

8. 
   Joshua Greisen|Mar 28, 2017 04:58pm|#8

   We are building in Yakima WA.