Composed of a closed cell polyisocyanurate foam core bonded in the foaming process to 1 2 thick duraboard an expanded perlite mineral aggregate board on one side and a fiber glass reinforced facer on the other.
Foam board roofing.
Foam roofing is a cool roof system that replaces tar gravel single ply and other flat and low sloped roofs.
These roofs are lightweight durable and seamless.
Foam roofing advantages of dura foam.
Eps is used under roofing over foundation walls and beneath siding.
Rigid roof insulation board.
Foam board sheathing insulation johns manville polyiso foam sheathing insulation boards provide a continuous layer of insulation to reduce thermal bridging and improve energy efficiency.
It provides an r value of 4 per inch of thickness and is the cheapest type of foam board insulation.
Polyiso consists of a uniform closed cell polyisocyanurate foam core and provides one of the highest r values per inch of any rigid insulation.
If you want to install rigid foam above your roof sheathing in climate zone 3 then 1 2 inch of rigid foam board is not ideal this rigid foam layer needs a minimum r value of r 5 and that s impossible with 1 2 inch of foam.
This foam board insulation is the rigid pink or blue panels that can be found at home centers in many different thicknesses.
As my article states you need a minimum of about 1 5 inch of eps 1 inch of xps or 1 inch of polyiso.