It is very important to understand the differences in the r values of polystyrene.
1 1 2 rigid foam r value.
1 844 989 1230 my account.
This product typically has an r value of 3 6 to 4 0 per inch of thickness.
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.
The r value is an improvement over the use of a short term r value but it is insufficient for predicting the r value of extruded polystyrene foam over the life of a building particularly since building professionals expect buildings to last at least 50 years7.
Multiply these by 1 5 for 1 1 2 thickness.
5 8 polyisocyanurate board foil faced 7.
Rigid insulation r value by comparison usually ranges from r 4 0 to 6 5 and may get as high as r 8 7 depending on the insulation material.
Traditional loose fill insulation such as fiberglass or cellulose has an r value between r 2 0 and 3 5 per inch of thickness.
Additional r value for a masonry wall constructed using these materials needs to add the insulating value of additional wall components typically included such as 1 solid foam polyisocyanurate r 8 extruded polystyrene r 5 expanded polystyrene r 4 or 1 of perlite r 2 7 and for an exterior air film winter no wind r 0 17 an interior.
Rigid insulation is usually made up of fibrous materials or plastic foams.
R value per inch of thickness.
Expanded polystyrene board 3 6 to 4 avg.
3 8 extruded polystyrene board 4 5 to 5 avg.