Roof Insulation Grades

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.

Roof insulation grades.

The table below shows what levels of insulation are cost effective for different climates and locations in the home. Falls in the middle of the three types of rigid foam insulation in both cost and r value. The r value per inch for different types of insulation varies depending on the. Grade 3 25 psi 172 kpa min compressive strength.

Insulation level are specified by r value. 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. The higher the r value the better the thermal performance of the insulation. 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.

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. Between 2 and 5 missing insulation. Class 2 faced with polymer bonded glass fiber mat membrane facers on both major surfaces of the core foam.

R value is a measure of insulation s ability to resist heat traveling through it. Used most in walls or below grade applications. Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation.