Closed Cell Spray Foam With 1 5 Mineral Wool In Attic

The r value of open cell spray foam is about 3 5 per inch although the r value can be different depending on the product.

Closed cell spray foam with 1 5 mineral wool in attic.

First spray foam has the best stc rating of all the options. Open cell spray foam r values. It can be used between wood framed walls and in the attic floor. Two types of spray foam insulation exist namely open cell and closed cell.

Oregon shepard add boric acid sodium pentaborate dehydrate and a proprietary component that includes a natural protein last i checked with them. In this case the typical expense of spray foam insulation installation is 2 128. In this case you have a choice of several prescriptive materials approved by the code as ignition barriers. The main drawback is high cost.

Open cell spray foam costs typically 0 25 to 0 50 per board foot and closed cell spray foam ranges from 0 90 to 1 50 per board foot. Open cell spray foam typically has an r value of 3 5 per inch and it should be noted that open cell does not form a tight air seal. Open cell spray foam has a low density and is many times applied in interior walls and areas that are hard to reach in a home. But the spray foam is still exposed to the attic and needs an ignition barrier.

Black mountain natuwool which is 95 wool with 5 polyester binder and is treated with borax. 1 5 mineral fiber insulation. In these humid attics the moisture is getting through the open cell spray foam by vapor diffusion not via air leakage. Spray foam insulation is available in open cell and closed cell.

Closed cell spray foam uses blowing agents with a high global warming potential and open cell spray foam needs a carefully detailed vapor barrier to prevent moisture accumulation in the sheathing. Spray foam with air. Mineral wool batts for 2 4 walls have an r value of 15 while a standard fiberglass batt made to fit in a 2 4 wall has an r value of 11 or 13. Why open cell oc spray foam is best for sound attenuation.

Mineral stone wool insulation batts are slightly better insulators than the off the shelf fiberglass batts sold at most lumberyards and home centers. However in real construction a batt would be cut to fit around utilities and boxes leaving sound transfer cracks. It ties with rock wool batts for an stc of 50 in a laboratory test environment. Top brands of wool insulation.

It performs much better than any form of batt for stopping air flow but it is not as complete of an air seal as closed cell spray foam.