Blown-in Cellulose Insulation

Maximizing the insulation for your green home is the most important step you can take towards reducing the heating and cooling energy requirements of your home. Many options are available to you, such as fiberglass batt, rigid or blown-in insulation. Let’s look at cellulose blown-in insulation, which, in my opinion, is one of the greenest options available today.

Why Use Blown-in Insulation?

Cellulose blown-in insulation is made of post-consumer, recycled paper, most often newspapers. With the new blowers available today, the insulation can be blown in and compacted to a high density. This will eliminate the settling of the insulation, which is what has happened with blown-in insulation applied 10 or so years ago.

By the way, did you know that fiberglass batt insulation also settles, especially if it was not installed properly, which sadly happens very often?

Blown-in insulation is the best option to make sure that the insulation is applied tightly and continuously around electrical outlets, piping, wiring and ductwork. It can reduce air leaks considerably, compared to having batt insulation installed. All those special boxes you can buy to prevent air leaks around electrical outlets have been developed to fix improperly installed batt insulation.

Doing it right in the first place is better, cheaper and saves you headaches and money in the future. A tight, high R-value insulation will also increase the comfort of your green home, and will minimize the required energy use for heating and cooling. A solar heating system can be sized smaller and will therefore also be more affordable.

Most providers of cellulose blown-in insulation operate within a limited geographical area, because the transportation of the insulation beyond a certain range is not feasible, due to the high ratio of volume/pound of the insulation. This means that you would be fulfilling another critical green component: buy local!

Where would I apply Blown-in insulation?

Besides insulating all exterior walls with blown-in insulation, you can also apply it in the garage ceiling and the attic floor.

Those living in the cold climates are familiar with the dangers of having ice-dams form. The dams form when the attic insulation has gaps and leaks. The heat from the rooms below will escape upwards and melt the snow on the roof. It then freezes again and an ice dam forms. More snow is melted, ice builds up and thaws again. The ice dam grows. The water from the melting ice cannot run down on the roof, because it is blocked by the ice dam. The path of least resistance is through the roof and into your home.

It takes skilled contractors to install batt insulation correctly at the edges where walls, attic and roof framing meet. Often the contractors do not take the time, or don’t know how, to prevent gaps and leaks in the batt insulation they apply. Blown-in insulation will reach those nooks and crannies and fill them up with insulation, thereby preventing heat from escaping and ice dams from forming.

Additional Benefits of Blown-in Insulation

Highly pact cellulose insulation inherently also prevents air penetration. Fiberglass batt insulation relies on correctly installed sheathing, gaskets, siding, etc.. Unfortunately these are very rarely installed correctly.

In addition to providing excellent thermal insulation, cellulose blow-in insulation will also provide very good sound proofing between rooms, from noisy pipes, showers and bathtubs. The spaces around bathtub and shower basins can easily be filled with blown-in insulation. Family members coming home late and wanting to take a shower, will no longer wake everyone up when the water runs. Of course, they might still slam the doors…

Insulating the wall between the family room and adjoining bedrooms is another good application of blown-in insulation. You will be able to sleep, while other family members play music, watch TV, and laugh in the family room.

If you have a door to separate the family room, you can turn the thermostat down in this room when it is not used for longer periods of time. With the insulation in between the family room and adjoining rooms, you will not loose heat from the warmer rooms to the cooler family room.

Any room that is only used occasionally, such as guest rooms, rooms for children who are away at college, can be thermally separated from the rest of the house by filling the walls with insulation.

What about Mold?

Cellulose insulation is treated with non-toxic boric compounds to protect it from mold. This treatment also provides fire and insect resistance.


I believe that one of the best options for providing good, lasting, environmentally friendly, non-toxic insulation for your home is to use blown-in cellulose insulation.