Can you paint over XPS to protect it from sun?
I put on a house addition with XPS on the exterior. I won’t be able to side it until next year, leaving the foam exposed to sun and elements.
Is it advisable to coat it with a latex paint or housewrap?
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David,
Here is some information on leaving Dow Styrofoam exposed to sunlight: "It should not be stored outside under sunshine for a prolonged period of time (over a month) to avoid excessive exposure to sunlight (UV). A sheet of polyethylene film may be used on top of the STYROFOAM Brand XPS Foam Insulation to prevent excessive exposure to sunlight (UV)."
The information is found on this website:http://dow-styrofoam.custhelp.com/app/answers/detail/a_id/3373/~/how-should-i-store-styrofoam%E2%84%A2-extruded-polystyrene-foam-insulation%3F
If you do choose to install polyethylene on top of the XPS to reduce UV exposure, be sure to remove and discard the poly when the siding is installed.
Latex paint works well to protect it from sun exposure. I've done it. I wouldn't try to push it much past one year, though. It does nothing to prevent damage from rodents and birds, which could be a consideration.