Fiberglass

Fiberglass has been the industry standard for insulation for many decades. It has dominated the market due to its ease of transportation and installation. Fiberglass is simply the cheapest option. Though we use fiberglass in limited applications, for numerous reasons we feel that it is the least desirable insulation option.

Fiberglass insulation is composed primarily from silica which is in abundant supply and easy to source. Perhaps for this reason fiberglass is composed of at most 30% recycled glass which is much more difficult and expensive to include in production. The low percentage of recycled glass adds to the high embodied energy it takes to produce fiberglass. By comparison, fiberglass is approximately 10 times more energy intensive to produce than cellulose.

Another issue with fiberglass is the potential health issues associated with it. We know from experience that it can cause severe skin irritations for workers and can trigger a reaction for people who are chemically sensitive. This is partially due to the phenol formaldehyde binder used to hold the fiberglass fibers together and partially due to fibers becoming airborne during installation. For this reason we use only formaldehyde free fiberglass insulation and prefer to work with a batt that is surrounded by a plastic covering.

The ease of installing fiberglass makes it the cheapest insulation option. A worker for a typical insulation contractor can install 2000 square feet of friction-fit fiberglass in an 8 hour period. But this speed of installation is also cause for its greatest short-coming. For insulation to perform at its rated R-value it cannot have any compression or voids. When installing fiberglass in a typical wall with plumbing, electrical and non-standard bay sizes it is virtually impossible to install it without dramatic voids and compression. Fiberglass installers are usually pushed to install as quickly as possible and installation quality is not a factor. Most people see a wall with installed fiberglass and don’t understand how detrimental all the voids are to the real-life performance of the insulation (see graph below). Even building inspectors allow egregious insulation jobs to pass inspection because they are not required to enforce installation quality and often times are not aware of insulation performance issues