Closed Cell Foam R Value Chart

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.

Closed cell foam r value chart.

The r value is r 3 5 to r 3 6 per inch so filling a 2 4 cavity yields about an r 13. For 6 inches r 15 or r 19 etc. When applied on the interior open cell spray insulation provides performance advantages that differ from those of closed cell spray foam used on the exterior. Both closed cell spray foam and open cell spray foam insulation can be used effectively in commercial building designs to allow the building to achieve energy efficiency and consistent performance.

As a benchmark one inch of solid wood has an r value of 1. Why spray foam insulation is so effective in meeting code requirements is that it has a higher r value per inch of product used than batts. It demonstrates the calculation method and does a good job of estimating the incremental r value attributable to an upgrade from open cell to closed cell foam. They contain low conductivity gases in the cells usually one of the hcfc or cfc gases the higher r values r 7 0 to 8 0 are the result of thermal resistance of the gases in the cells.

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. For example closed cell spray foam depending on brand can offer an r 6 or r 7 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. Closed cell foam r6 r8.

While it s true that actual whole wall r values will usually be higher than the values shown in the table due to the r values of the sheathing drywall. Closed cell spray foam r values. Closed cell spray foam insulation is vapor and air impermeable and is applied with a minimum of 2 on average with use on on interior and exterior building applications. Closed cell spray foams are between 2 and 4 lbs.

That said the table is useful. In comparison an inch of blown fiberglass insulation has an r value of 3 1 3 4 and an inch of blown cellulose in an attic has an r value of 3 2 3 7. Polyurethane and polyisocyanurate are both closed cell foams. They sport an r value of 6 0 8 0 per inch of insulation about double their open cell foam counterparts.

The r value for closed cell is typically around 6 7 at 1 thick and varies by manufacturer. 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. Note that some commercial and industrial buildings may require higher r values. Closed cell spray foam insulation.

It has a lower r value per inch than closed cell foam and is vapor permeable.