Styrofoam for insulating rim joists
We just moved into a new home this summer, and I am finally getting around to air-sealing the basement starting with rim joists. Half of it had already been done with spray foam which keeps that area nice and warm. I don’t need to touch this area at all. But, some of the other half has been done using 1 1/2″ styrofoam panels. They are not sealed around the edges, just glued to the rim joist. There are no markings on them, so I can’t even tell who made them. They look like what those old styrofoam coolers were like. Just plain white styrofoam.
I know styrofoam is definitely not green, so my questions are these:
(1) do I remove them all, and replace with more green rigid foam, and seal around the edges?
(2) do I just leave it, add rigid foam on it, and seal it?
(3) do I just leave it, and seal it?
Thanks for your opinions!
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