What is Blown-In Insulation?

Blown-in insulations are made of any number of different materials including fiberglass, rock wool and cellulose. The one thing they have in common is that they are all fed into a pneumatic blowing machine and blown under high pressure through a long flexible hose into attics and walls.

There are three main types of blown-in insulations. Fiberglass is the most popular and preferred material among homeowners. It is spun from molten glass into fibers, and is an extremely effective insulation material because it has millions of tiny pockets to resist the flow of heat and cold.

Perhaps the best blown-in fiberglass insulation is InsulSafe 4, produced by the nation’s leader in fiberglass technology, CertainTeed Corporation. InsulSafe is non-combustible, non-corrosive to pipes and wires, and will not provide sustenance for pests or vermin. Its pure white color also adds a look of quality.

The second type of blown-in insulation is rock wool. It is similar to fiberglass except that it is spun from slag and other rock-like materials instead of molten glass.

Cellulose is the third type of blown-in insulation. It is made from ground-up newspapers. An important thing to keep in mind is that cellulose is naturally flammable and must be treated with chemicals to make it fire retardant. It will, however, still burn when exposed to a heat source like recessed lighting. Also, the product will settle over time which will reduce its R-value.

Fiberglass, rock wool and cellulose come in slightly compressed bags. The contractor then loads the insulation into a blowing machine in his truck to be conditioned as it is installed in your home.

WHAT ARE THE BENEFITS OF BLOWN-IN INSULATIONS?
Blown-in insulations have several benefits. The major one is that they offer completely uniform coverage especially in hard-to-reach areas. They also can be blown into areas that a do-it-yourselfer cannot reach. In addition, they can be installed in any thickness and density to achieve practically any desired R-value. R-value is the measure of an insulation material’s resistance to heat flow. The higher the R-value, the greater the insulating power. Make sure you think in R-values, not just inches, when considering any insulation material.

Because coverage is so complete, blown-in materials become an excellent thermal blanket, leaving no nook or cranny exposed for heat to escape. They help to save energy and make a home more comfortable.

Most blown-in fiberglass insulations, including InsulSafe, will maintain their R-values for the life of a home. Some other types of materials can settle over the years, therefore, losing some of their thermal efficiency.

HOW WILL BLOWN-IN INSULATION
BE INSTALLED IN MY ATTIC?
First, the contractor will run the insulation hose into your attic through any available opening. Next, he will blow the insulation so it flows approximately 4 ft. to 10 ft. in front of the nozzle completely covering the attic floor. Contractors usually insulate three or four joist spaces from one position by moving the hose back and forth in the direction of the joists.

The hose is kept close to the floor during the installation process to ensure that the material is being applied both under and over obstructions such as cross-bracing and wiring

If you have a semi-finished attic, the insulation contractor will remove some of the floorboards exposing a joist section. The contractor then blows insulation into the cavity. After the material has been installed, he will put the floorboards back into place and move to the next joist section until the job is done.

WHAT’S INVOLVED IN INSULATING SIDEWALLS?
Insulating sidewalls requires a few more steps than insulating an attic floor.

Typically, a contractor will begin the job by carefully removing some of your home’s outside siding. Next he will drill small openings into the wall cavity. Usually two holes are drilled per stud space, however, some homes require three or four openings depending on their construction.

Once all holes have been drilled, the contractor will begin blowing insulation into the wall cavities. In most cases, he will use a special sidewall nozzle to blow in the material. Once the cavity is filled with insulation, the holes are plugged with circular pieces of wood and the siding is replaced.