Using XPS and Polyiso on Wall with Rainscreen
gbcif
| Posted in Green Building Techniques on
I have half a palate of 2″ xps I would like to use up. Can I apply 2″ xps against the 1/2″ zip and then put a 1″ over it of polyiso? I need 3″ total for this wall. I’ll have a rainscreen with corrugated metal over it.
(I can get used polyisco) thoughts if there will be any issues? Maybe the XPS on the outside? Somebody the building will be all polyiso when I run out of XPS.
Thanks
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Replies
XPS R value improves (vs degrades) when cold - so in a cold climate, put it on the outside.
+1 for putting the XPS on the exterior, with the polyiso closer to the interior, as Jon mentioned.
Yes, you can get used/reclaimed polyiso. 2" and thinner sheets tend to be the most commonly available, but I've seen up to at least 4" thick before. The reclaimers have what they have though, so you won't always be able to get exactly what you want.
Bill