Source for Polyisocyanurate board?
 

I live Manitoba Canada - does anyone have a close source for Polyiso board? My understanding is that this rigid styro board has a higher heat rating, due in part to a foil barrier on one side. I'm having a little trouble sourcing it around here, but it seems to be what people are using for solar collector projects.

Ideas?

Thx.

apparently Menards in Grandforks has it. Road Trip!

It does not hold up to sunlight, that is the main reason for the foil face but it does hold up to heat really well, most lumber yards should be able to get i if they do not carry it, sometimes its foil faced, sometimes it's fiber faced, but if you ask for faced foam that is what you are getting.

Hi,
As Ryland says, the insulation itself is much more resistant to heat that polystyrene. Polystyrene starts to have trouble around 130F, while polyiso can go above 270F.

I found that around here several lumber yards have it, but did not know it by the name polyiso or polyisocyanurate -- you had to go look at what they actually carried to see.
If its polyiso, it will say polysiocyanurate somewhere on one of the face sheets. You may find that a local place has it, but just does not know it by that name. Atlas and Firestone are two of the common brands.

Gary

Just made the pilgramage to Menards in Grandforks last weekend. Cheap! Insulation down there is half what it costs here, and they had plenty of different thicknesses from 1/2 to 1". I opted for the 1". Now to start construction...