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Determining Type of reclaimed EPS

Brian_D | Posted in Green Building Techniques on

Hi All,

Is there a way to determine the type of EPS, I or II, when buying it reclaimed? I am looking for recycled EPS for exterior foundation walls and sub slab. My project is in Stowe, VT and there are a number of relatively local options for obtaining recycled EPS but no one can say for sure what the type, or PSI rating, of the foam is.

Is it safer to use recycled XPS from an engineering viewpoint?


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  1. Expert Member
    KOHTA UENO | | #1

    If you have the option of weighing a sample of the EPS, you can calculate the density, and cross-reference it to the typical material properties by type (per attached).

    1. charlie_sullivan | | #2

      That assumes it's dry, which is probably the case but not a given for reclaimed.

      Another option would be to get a sample, measure the thickness with calipers, put some heavy weight on it, and measure again. Comparing to a reference sample of each type would be best, if you don't have actual lab equipment to do this.

  2. Expert Member
    Dana Dorsett | | #3

    Type-I EPS (1lb per cubic foot nominal density) is a bit too crumbly to be reclaimed. Thinner sheets are usually made with facers to keep it from falling apart in handling.

    Most reclaimed roofing EPS is Type-VIII (1.25lbs per cubic foot nominal density) or Type-II (1.5lbs) .

    The psi rating of the foam is completely irrelevant for most residential applications- even Type-I is fine under a slab or as insulating sheathing. The only place where the ratings might matter is under foundation footings, and it would have to be specified by an engineer.

    1. Brian_D | | #4

      thanks Dana, exactly the info I was looking for. It would just be sub slab with partition walls above. Hard to pass up saving 40% using recycled EPS.

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