Why Fiberglass Insulation is Still the Insulation of Choice

Fiberglass insulation has been one of the most popular home insulation options for decades for one incredibly simple reason: it works, and it works well. It also helps that it is still one of the most cost efficient insulation options on the market today. In fact, despite recent rises in other forms of insulation, you’ll find that fiberglass insulation is still the insulation of choice for most home builders, contractors, and heating and cooling professionals. But why is this deceptively simple product the go to for so many different companies? Let’s take a closer look at fiberglass insulation and find the answer to that question.

Origins of Fiberglass Insulation

Prior to the 1940s most home insulation was composed of inefficient and sometimes highly combustible — or otherwise dangerous (hello, asbestos) — materials. In the early 1930s, scientists at Owens Corning began developing a new alternative to these materials out of fiberglass. Fiberglass had originally been created when a researcher named Dale Kleist attempted to create a vacuum seal between two blocks of glass. During his attempt, an accidental stream of high-pressured air created thin fibers out of some of the glass.

As glass is generally known to be a poor heat conductor, the Owens Corning scientists decided to see if they could create a non-conductive form of home insulation out of these thin glass fibers that had come to be known simply as fiberglass. They were successful, and fiberglass insulation began to be used in many homes and other buildings during the 1940s.

How Fiberglass Insulation Works

As stated above, glass is a poor conductor of heat energy. This poor conductivity, coupled with the unique composition of fiberglass — a multitude of thin, glass fibers woven together into a mass of silicate and air pockets — are uniquely useful in insulating homes. But why? In short (and without getting too technical) it’s because the air pockets that are created by the mass of glass fibers trap both warm and cool air and prevent heat from transferring through the walls of a building. That means that your home can stay at, or near, your desired temperature more efficiently, saving you money on both heating and cooling costs throughout the year.

In addition to preventing heat, cold, and sound from moving through walls, fiberglass insulation is also inherently moisture resistant, fire resistant, and sound absorbent. In fact, those same air pockets that help prevent the transference of heat are what provide a simple but effective sound dampening effect.

Improve Your Home’s Energy Efficiency with Fiberglass Insulation

Because fiberglass insulation helps prevent the transference of heat, form a warm area to a cool one, it works to keep homes warmer in the winter and cooler in the summer. This helpful quality is one of the main reasons why fiberglass insulation has been one of the top choices for home builders and home remodelers for over 75 years.

There are several different methods of using fiberglass for home insulation, but one of the most common is the ubiquitous pink (or green, or blue, or yellow depending on the manufacturer) rolls and precut batts of squishy, moldable fiberglass sandwiched between moisture barriers that look like nothing more than long rolls of paper. This form of fiberglass insulation is common and popular because it is easy to work with and can be used almost anywhere by both amateurs and professionals.

The other common form that fiberglass installation takes is far more likely to be used by a professional than a do-it-yourselfer. Blown-in loose-fill fiberglass insulation is typically installed using pneumatic devices that allow the installer to fill virtually any wall cavity with insulation with relatively little effort. When properly installed, blown-in loose-fill fiberglass doesn’t settle, which allows it to maintain the desired R-Value performance (i.e. thermal resistance) for a long, long time. It can even be installed over previously installed batt insulation to increase the overall R-Value in renovatio projects. Of course, proper safety gear should be worn at all times when working with fiberglass insulation because the fine silicate fibers are a skin irritant to almost anyone who comes into contact with them. This is double true of blown-in fiberglass insulation.

One last thing. Because the air pockets present in the product are an integral part of how fiberglass insulation works, you should make sure that your fiberglass insulation is never compressed in order to fit into a small area. It is best to make sure you or your contractor is using insulation that has your desired R-Value and is designed to fit into the planned depth of your walls, attic, or other installation location.