Polyurethane Foam R Value Per Inch

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.

Polyurethane foam r value per inch. Note that the material the insulation is made from will change the r value as well. Closed cell foam offers the best r value per thickness of any insulation at about 6 5 per inch. For 6 inches r 15 or r 19 etc. A 3 5 inch deep fiberglass rockwool or recycled denim batt for a typical 2 4 wall may say it provides r 11 or r 13 depending on fiber density.

A typical 2 4 stud filled with open cell spray foam will have an r value. The r value is r 3 5 to r 3 6 per inch so filling a 2 4 cavity yields about an r 13. Foam board insulation. Insulation blankets batts and rolls spray foam insulation.

Aerogel has the next highest r value about r 10 to r 30 per inch followed by polyurethane pur and phenolic foam insulations with r 7 per inch. Why spray foam insulation is so effective in meeting code requirements is that it has a higher r value per inch of product used. Blown in or loose fill insulation. If you want to install spray foam in a stud wall and price is no object then it would seem to make sense to specify closed cell spray foam right.

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. Radiant barriers and vapor barriers are not rated by. Vacuum insulated panels have the highest r value approximately r 45 in u s. Here are the installation methods from lowest to highest average r value per inch.

Like polyiso foam the r value of closed cell polyurethane insulation can drop over time as some of the low conductivity gas escapes and air replaces it in a phenomenon known as thermal drift or ageing. 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. R values are additive so you can multiple the number of inches of insulation thickness times the r value to arrive at a total insulation value. Expanded polystyrene foam eps is the cheapest and least used foam board product on the market.

Closed cell spray foam insulation. Open cell foam cells are not as dense and are filled with air which gives the insulation a spongy texture and a lower r value. Open cell spray foams are between 5 and 1 lbs per cubic foot and have an r value of 3 0 4 0 per inch of insulation. Closed cell spray foam r values.

This product typically has an r value of 3 6 to 4 0 per inch of thickness. Open cell spray foam has an r value of about r 3 7 per inch while closed cell spray foam has an r value that may be as high as r 6 5 per inch. The r value of.