Closed Cell Spray Foam With 1 5 Mineral Wool In Attic

The main drawback is high cost.

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

As i noted in a different article air leakage through spray polyurethane foam open cell spray foam only needs to be 3 or 3 5 inches thick to form a decent air barrier. Mineral stone wool insulation batts are slightly better insulators than the off the shelf fiberglass batts sold at most lumberyards and home centers. 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. Black mountain natuwool which is 95 wool with 5 polyester binder and is treated with borax.

Most ceilings are made of 1 2 drywall. 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.

Spray foam insulation is available in open cell and closed cell. Spray foam with air. 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. The foam must be thick enough to meet minimum code requirements.

Two types of spray foam insulation exist namely 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. It ties with rock wool batts for an stc of 50 in a laboratory test environment. 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.

1 5 mineral fiber insulation. Why open cell oc spray foam is best for sound attenuation. In this case the typical expense of spray foam insulation installation is 2 128. However in real construction a batt would be cut to fit around utilities and boxes leaving sound transfer cracks.

It can be used between wood framed walls and in the attic floor. 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. In this case you have a choice of several prescriptive materials approved by the code as ignition barriers. Top brands of wool insulation.

Oregon shepard add boric acid sodium pentaborate dehydrate and a proprietary component that includes a natural protein last i checked with them.