In this video dow chemical rep kevin and i will tell you about the differences between.
Polyiso vs xps attic.
Xps is degraded by uv light but the facers on polyiso insulation protect the core from such damage.
So if you are looking for suggestions we would say go for the eps and if you want added protection source one with a foil backing.
Extruded polystyrene xps is somewhat lower than polyiso.
Another difference between the polyiso and xps insulation concerns ultraviolet light.
A thermosoftening plastic or thermoplastic is a polymer that softens or turns to a liquid when heated.
For mineral fiber board r values vary between supplier but are around r 4 0 inch significantly less than for polyiso.
Polyiso is a thermoset material meaning it is permanently rigid and cannot be melted back to liquid form.
Thermoset materials are generally stronger that thermoplastic due to the network of bonds and are better suited for high temperature applications.
We always choose and recommend eps over xps due to the fact that xps has much higher greenhouse gas emissions than eps.
There are a number of factors that are very important to the installer and building owner but are not part of the specifications.
A thermosetting plastic also known as thermoset is a polymer material that irreversibly cures.
I think there are two good choices for exterior rigid foam insulation.
Some of the key attributes are shown here.
Xps is a thermoplastic material which softens or turns to a liquid when heated.
Polyiso is classified as a thermoset material.