Download PDF version (638.3k) Log In or Register to view the full article as a PDF document.

Superior Cellulose

These days, no one whose opinion matters denies that cellulose is a first-rate insulation material. But if you want to start an argument, just bring up the subject of quality control. Unlike the fiberglass industry — which is dominated by a handful of large manufacturers whose uniform offerings are available coast-to-coast — cellulose producers tend to be small local operators, not all of whom are equally meticulous about turning out a consistently high-quality product.


Installers routinely complain about clogs and equipment malfunctions caused by roughly processed newsprint (“It’s no good if you can still read the headlines,” one installer told me) or contaminants like mixed paper, plastic bags, and who knows what else.

In recent years, several manufacturers have tried to address these problems. The latest is FiberAmerica, a startup operation that opened its doors last September in a brand-new $5.5 million factory in Allentown, Pa. Under its Green Seal brand, the company offers a variety of formulations for loose-fill and damp-spray applications.

FiberAmerica marketing specialist George Day says that in addition to producing cellulose in what he calls “the most technically advanced production facility in the country,” the company benefits from hiring managers with extensive field experience. “With our guys having installer backgrounds, they know from experience how an inconsistent or contaminated product can really screw things up,” he notes.

To assure a superior product, Day says, FiberAmerica purchases only clean, sorted newsprint — primarily “over-issued” news (unsold newspapers that get returned from retailers) — for its raw material and sorts the papers a second time after taking delivery. The company also has an extensive testing program that includes an outside testing service as well as in-house quality-control procedures: “On an hourly basis we pull bags out of the line and test a sample in our on-site laboratory.”

Green Seal cellulose insulation is available throughout New England and the Mid-Atlantic as well as in a portion of the Midwest. Prices vary based on volume, but Day says they’re on par with those of the company’s regional competitors. More information is at

Blow-In Plus Foam

The Blow-In-Blanket System (BIBS) was introduced in 1983. For the first time, builders could pack their walls with custom-fit high-performance insulation. The key ingredient in a BIBS job is the mesh fabric stapled onto the stud faces, which allows cavities to be uniformly packed with loose-fill fiberglass to a density of 2 pounds per cubic foot. According to Dan Stoner, the brand manager for Blow-In-Blanket, this high-density fill (it’s two to four times denser than batt insulation) yields an R-value of 4.2 per inch and compares favorably with cellulose in stopping air movement.


Recently the company started offering the BIBS HP (Hybrid Performance) System, which is designed for builders in extreme hot or cold climates whose buildings may require an extra measure of air-sealing. Using what’s known as the “flash and fill” method, BIBS HP installers coat the wall cavity with a thin layer of high-density closed-cell polyurethane foam before applying the mesh and blowing the fiber. Builders who choose the minimal 1/2-inch-thick layer of foam can expect an R-16 rating for a typical 2x4 wall. One inch of foam boosts the R-value to 17 and serves as an air barrier.

Although pricing is set by individual BIBS dealers, Stoner estimates that the cost for BIBS HP generally runs about halfway between a standard BIBS installation and a full polyurethane foam job. He also says that fiberglass insulation delivers better sound control than foam. “We believe that BIBS HP provides the best qualities of fiberglass and foam at a price that’s more affordable than foam alone,” he says.

BIBS installations can be performed only by authorized contractors. The company says it has a network of 600 contractors throughout North America who have insulated more than 2 million homes since 1983. About 50 of those contractors are authorized to install BIBS HP. Go to to find out more.

Structural Foam Sheathing

Placing rigid foam on the outside of a building is a proven technique for boosting R-value and reducing air leakage and thermal bridging. But foam is not a structural component, so it must be applied over wood sheathing or let-in bracing. Until now.


Though it looks like a typical polyisocyanurate panel, Styrofoam SIS Structural Insulated Sheathing from Dow is laminated with compressed fiberboard, which provides a solid backbone for withstanding racking shear and transverse wind loads.

The IRC and the IBC have approved the insulation board for use in most areas as either continuous sheathing or as braced-wall panels with nonstructural rigid panels in between. (In seismic and high-wind zones, an engineered solution is still required.) Instructions for a code-approved installation are exacting. Framers must follow a precise fastening schedule using specially approved nails or staples. They must also install the sheets vertically and provide blocking on all edges.

Builders who grumble about the complex fastening process may find other features much to their liking. The exterior face of the panel is a code-approved water-resistive barrier that eliminates the need for housewrap as long as the seams are carefully sealed with Dow’s Weathermate construction tape. “You put it up and tape the seams, and you eliminate one trip around the house,” says Dow marketing manager John Hammer.

“Another thing that guys in the field tell us they really like about the product,” he adds, “is the fact that it’s only about 16 pounds for a 4x8-by-1/2-inch board. Compare that to a 45-pound sheet of OSB and you can imagine that framers going up and down ladders all day really appreciate the weight savings.”

Styrofoam SIS panels are manufactured in 1/2-inch (R-3) and 1-inch (R-5.5) thicknesses. Due to the fiberboard content, these R-values are slightly lower than those of corresponding thicknesses of nonstructural polyisocyanurate. Panels come in 8-, 9-, and 10-foot lengths. A 4x8-by-1/2-inch sheet size sells to builders for around $18. To find out more, go to