Blown insulation is wall insulation that is quite literally blown into place with specialized equipment, which makes it easy to install quickly and allows for non-linear spaces to be more easily insulated, instead of having to cut and tack multiple batts into place. The two main types of blown insulation are fiberglass and cellulose, and while both seek to perform the same function in your home, their distinct material qualities confer a number of unique characteristics to each type of insulation. Understanding the differences between fiberglass and cellulose insulation can help you choose which type of blown insulation is best for your needs.
Fiberglass insulation is made out of extremely tiny strands of glass. Fiberglass that is blown into place will stay in place, rarely shifting or changing shape unless it is exposed to water or outside elements. Fiberglass is also extremely fire resistant, and will not burn in the case of a house fire – though it may melt.
However, fiberglass insulation can begin to degrade in extremely low temperatures, reducing its overall effectiveness and the comfort levels within your home while also increasing your energy bills. In addition, the extremely fine nature of fiberglass strands means that they pose a health risk during installation. While this is offset by the wearing of protective gear and the use of proper equipment, care should be taken to never expose or handle your insulation with bare skin or uncovered eyes and mouth in the future due to potential health concerns.
Cellulose, on the other hand, is made out of recycled paper pulp, like newspapers and other paper products. This reduces your home's overall environmental impact when compared to fiberglass, especially since your insulation can be recycled in the future if you ever need to replace it. Further, cellulose insulation is able to work effectively in both high and low temperatures, with little fluctuation in its effectiveness.
However, cellulose is susceptible to fire damage, since it is made out of paper. While it is treated with a fire retardant, which also acts as a pest repellent, in the event of a house fire cellulose insulation will burn and can contribute to the spread of the fire if the temperature is high enough, which should be taken into consideration. Further, cellulose insulation can settle or clump over time, which can create cold spots and drafts within your home that will require further work to fix.