Foam Roof Insulation R Value

Corrosion problems when in contact with steel roofing moisture.

Foam roof insulation r value.

8 3 4 4 8 2 20. Johns manville r panel rigid roof insulation board offers r values of up to r 23 6 providing high thermal efficiency. R panel is manufactured with a closed cell polyisocyanurate foam core bonded to fiberglass reinforced facers and designed for use over metal nailable and non nailable roof decks with a variety of membrane systems. Closed cell spray foam has a far better r value per inch than other less effective insulations like cellulose fiberglass or even open cell foam.

Closed cell spray foam insulation. Products provide superior insulating properties. These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation. Foamular extruded polystyrene xps rigid foam insulation offers foamular extruded polystyrene xps rigid foam insulation offers a comprehensive line of products choose the strength you need from 15 to 60 psi and exceptional moisture resistance.

R 0 77 30 phenolic foam insulation r values. 4 5 21. For example if you have a type of insulation that has an r value of r 5 per inch of thickness you will need a depth of 6 inches of this insulation installed your attic to reach r 30 if you live in zones 2 or 3. Expanded polystyrene foam eps is the cheapest and least used foam board product on the market.

This product typically has an r value of 3 6 to 4 0 per inch of thickness. The r value of closed cell foam is r 6 5 7 per inch. All these have r values ranging from r 3 2 to r 3 8 per inch. Expanded polystyrene insulation is similar to the foam used for packing peanuts and it s typically used for insulated concrete forms also knows as icf s.