Roof Insulation Grades

Between 2 and 5 missing insulation.

Roof insulation grades.

Up to 2 missing insulation. Find your zone on the map and then use the chart to determine the level of insulation you need to properly insulate your attic walls floors and crawlspaces. Used most in walls or below grade applications. R value is a measure of insulation s ability to resist heat traveling through it.

While there are additional considerations such as venting and moisture problems to take into account when you insulate under floors the united states department of energy recommends an r 25 rating in cold climates and an r 11 in warmer parts of the country. Insulation level are specified by r value. Grade 3 25 psi 172 kpa min compressive strength. Occasional very small gaps are acceptable in another place the standards say if the exterior sheathing is visible from the building interior through gaps in the cavity insulation material it is not considered a grade i installation grade ii.

The higher the r value the better the thermal performance of the insulation. For a 1 in thick 4 8 panel. Class 2 faced with polymer bonded glass fiber mat membrane facers on both major surfaces of the core foam. Recyclable and at about r 5 per inch costs around 42 per sq.

Falls in the middle of the three types of rigid foam insulation in both cost and r value. Extruded polystyrene xps easily recognized by its blue green or pink color. Type iii faced with a perlite insulation board on one major surface of the core foam and an organic inorganic asphalt.