Loose-fill Wool Insulation from Oregon Shepherd
I've been at the West Coast Green conference in San Francisco the past three days and have spend a good portion of that time checking out the trade show. One of the highlights is a loose-fill wool insulation from Oregon Shepherd.
I was surprised to learn at the conference--from a different exhibitor, actually--that 90% of the wool that is shorn off sheep in the U.S. is thrown away. Either there isn't a market for it, or there's an inability to compete with inexpensive processed wool from New Zealand. Thus, most wool is a waste agricultural product, making wool insulation an environmentally attractive commodity.
Unlike wool batt insulation products available from New Zealand, Oregon Shepherd blowing wool is 100% wool fiber; there is no added polypropylene fiber. The wool is sourced from throughout the western U.S., and wool is used that is not suitable for textile manufacturing, according to Bob Workman of the company.
Wool has inherent fire-retardant properties. At the conference here, I heard a story about a warehouse in Texas filled with burlap-wrapped bales of wool. The warehouse caught fire, burning to the ground, and the burlap burned off the bales of wool, but the wool remained unburned.
Oregon Shepherd enhances wool's inherent fire-retardant properties with a borate additive. The company uses a proprietary formulation using a natural protein to covalently bond the borate compound to the wool fibers. The material has been tested to ASTM E-84, E-1496, and C-518 standards, and passes with flying colors, according to Workman.
Along with increasing the material's fire resistance, the borate provides insect resistance--eliminating concern about moth infestations, for example.
Oregon Shepherd is manufactured in the Portland area. Having shipped their first product in June, 2010, the company has been expanding by 50% per month, and is soon to move into a new 18,000 square-foot factory north of Portland. Product is being shipped nationwide in 200-pound reinforced-nylon bags.
Oregon Shepherd is installed like loose-fill fiberglass or dense-pack cellulose, using standard insulation blowing equipment. Photos here show installation using mesh, which is stapled to the inner face of studs. Though I haven't used the material, it looks as if it doesn't pack as tightly as cellulose insulation, so there may be slightly greater air flow through the material.
The insulation goes in at a density of about 1 pound per cubic foot and insulates to slightly over R-4 per inch, according to the manufacturer's literature.
As for cost, Oregon Shepard sells for $2.75 per pound. For a 2x4 wall, providing R-13 insulation will cost about $0.67 per square foot, compared with $0.35 – 0.40 for fiberglass, $0.50 to 0.55 for cellulose, and $0.85 for cotton, according to Workman.
I've looked at wool-batt insulation products, and I've always wondered why there isn't a loose-fill wool. Now there is. The product looks like a winner!
For more information:
Oregon Shepherd
Portland, Oregon
888-269-9665
See more on this product in the GreenSpec Guide
Alex Wilson is the executive editor of Environmental Building News and founder of BuildingGreen, LLC. In addition to this product-of-the week blog, he writes the weekly Energy Solutions blog. To keep up with his latest articles and musings, you can sign up for his Twitter feeds.