Cellu-Spray Learning Center

JLC Article



Insulating with cellulose will make it easier to heat and cool your building. You will end up with an energy efficient building. By reducing heating and cooling costs you can quickly recoup the investment in this superior product.


A building insulated with cellulose is significantly quieter than if fiberglass insulation is used. You won’t hear mice in the walls first of all due to the nature of the installation and the borates present in the cellulose.

Densly packed cellulose absorbs sound by dampening vibration and blocks the pathway of airborne noise. High-density materials absorb sound better than lower density materials. With an installed density of greater than 3.0 lbs./cu. ft., cellulose insulation effectively absorbs sound by dampening vibration and blocking the pathways of air-born sound. Good sound absorbers are impervious and dense.



Nu-Wool® Insulation is made with 100% Boron-based, E.P.A. registered fungicide, which makes it resistant to mold. Because of the density of the material when installed by Cellu-Spray, there is literally no air movement in the wall cavities, which reduces the favorable conditions for mold growth.

Airflow accounts for 98% of moisture movement. Since fiberglass is not an air barrier it provides no protection against moisture and mold. Cellulose is so effective at blocking airflow and managing moisture that you don't need a poly vapor barrier. While the air-blocking capability of high-density cellulose insulation prevents moisture flow, the borates in our specially treated NuWool Wallseal cellulose insulation inhibits mold and fungus growth from any condensation. Our cellulose insulation wicks moisture away from the surrounding building components and carries it to drier areas.


Nu-Wool® Insulation is so effective, it actually improves the fire safety of existing construction. While fire roars right through fiberglass, adding cellulose insulation to an un-insulated wood wall increases its fire-rating by 15 minutes.

Studies of actual fires and demonstrations have shown that the dense fiber structure and fire retardants in cellulose insulation slow the spread of fire through a building giving occupants more time to escape and fire fighters more time to save the structure. During the manufacturing process cellulose fibers are permanently impregnated with a boric acid fire retardant. Cellulose insulation achieves a Class-A noncombustible rating and passes a strict battery of Federal 16 CFR Part 1209, ASTM E-84 smoldering, ASTM E-970 flame spread and ASTM E-119 fire endurance testing. Testing by Oak Ridge National Labs (1990)1, US Testing Company (1991)2, UL (1993)3 and US Borax (1994)4 all established that the fire retardant chemicals do not degrade over time and are permanently bound to the cellulose fibers.


Mice love fiberglass insulation. It doesn’t burn their eyes like the boric acid that Nu-Wool® cellulose contains and it’s easy to move around in. If you don’t want your home to become an experiment in mice habitation choose cellulose instead.

A densely packed bay of cellulose is not a nice place for vermin. If mice are able to get into the wall they will have to hold their breath and dig into the tightly compacted cellulose. The boric acid that the NuWool® Insulation is treated with to act as a fire retardant burns their eyes and the females don't want to have their young in it. You won't find insects, snakes, or mice in NuWool® insulation because of the boric acid. Keep your pets where they belong, NOT in the walls or attics of your building! The density of cellulose also makes it a superior sound barrier - achieving STC ratings as high as 45 in a standard 2x4 wall.



NuWool® Insulation is manufactured from recyled newpapers. These fibers are treated with boric acid and an E.P.A. registered fungicide. It is considered a “nuisance dust” by the E.P.A. In addition to Boric acid being non-toxic to humans it is also an effective mold inhibitor so your home will have better indoor air quality.

Non Toxicity and indoor air quality. Mold and poor indoor air quality have become a major issue in the last 10 years as more people have become victims of sick building syndrome . Research, conducted by various agencies such as the Environmental Protection Agency (EPA), has shown that the quality of indoor air can be many times worse than that of the outdoor air. Given the fact that many people spend as much as 90 percent of their time indoors, the health risk due to indoor air pollutants is a significant public health concern. Often the air we breathe inside is effected by a range of pollutants from toxic mold spores to high counts of pollen or other pollutants. Ineffective insulation will contribute to this problem as it allows air to move through it carrying various pollutants. Often fiberglass insulation will have mold or mice droppings in it that is then carried into the house since it doesn't provide a good air barrier! Cellulose is non-toxic and when properly installed provides a dense wall cavity that slows or stops the flow of air through the material. Not only does this lead to a more energy efficient house, but it also means that you can now control the flow of fresh air into your home. Build it tight, ventilate it right . This is the mantra for high performance homes. Each house needs so much fresh air for it's occupants. If a house is too tight, it is not healthy. There are a number of different strategies for getting enough fresh air, especially in the heating season. http://www.epa.gov/mold/moldresources.html


The biggest benefit to the planet will come from the reduction in energy needed to heat and cool a building insulated by Cellu-Spray. If protecting the environment is important to you, there is no better choice than this insulation. It is composed of 83% recycled materials, compared to 25% for fiberglass and 9% for foam, which is made from petroleum.

Our planet is in trouble. We are running out of clean air and clean water and it's getting hotter. Cellulose insulation also takes significantly less energy to produce, which means less pollution in the air we breathe and fewer greenhouse emissions in producing cellulose insulation.