Achieving greater r values in attics the higher the r value the better the thermal performance of the insulation.
Roof insulation grades.
For a 1 in thick 4 8 panel.
Up to 2 missing insulation.
Used most in walls or below grade applications.
The higher the r value the better the thermal performance of the 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.
Extruded polystyrene xps easily recognized by its blue green or pink color.
Recyclable and at about r 5 per inch costs around 42 per sq.
Class 2 faced with polymer bonded glass fiber mat membrane facers on both major surfaces of the core foam.
Falls in the middle of the three types of rigid foam insulation in both cost and r value.
Grade 3 25 psi 172 kpa min compressive strength.
Insulation level are specified by r value.
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.
The table below shows what levels of insulation are cost effective for different climates and locations in the home.
R value is a measure of insulation s ability to resist heat traveling through it.