Throughout history, people have used various materials to insulate their homes. Ancient Egyptians made their houses out of mud bricks while Vikings plastered mud and straw between the logs that made up their homes.
During the Industrial Revolution, asbestos became popular. This was due to manufacturers using steam for their machinery which had to pass through pipes. These pipes got hot so companies wrapped them with asbestos to keep workers safe.
Asbestos
As humans changed the way they lived, building materials also evolved. Earth and stone gave way to glass, iron and concrete. These new materials needed insulation to protect them from extreme temperature fluctuations.
Asbestos became a popular insulation material during the industrial revolution. Its heat-resistant properties made it ideal to keep hot factory machines from overheating. Asbestos was also used in roofing shingles, cement, shipbuilding, fireproofing and auto brake pads. Unfortunately, asbestos was also known to cause serious lung diseases. The companies who mined and sold asbestos knew of the health risks but hid them from workers and the public.
During the 1930s asbestos use began to decline as scientists discovered its negative health effects. It was eventually banned in the United States and many other countries.
During this time fiberglass and cellulose insulation started to rise in popularity. Fiberglass was often shaped into blankets called “batts” that homeowners could easily install in their homes. Cellulose was a blow in product that was much easier to incorporate into home structures than the flat blankets of asbestos or fiberglass. The 1940s and 1950s saw the appearance of plastic foams (polystyrene, polyurethane) that would eventually overtake natural materials as the main source of insulation for homes. Today, Armstrong is experimenting with other foam products including cellular glass, expanded perlite and aerated concretes to create innovative insulation for the 21st century.
Fiberglass
Prior to the industrial revolution, ancient civilizations used a variety of organic materials to insulate homes and buildings. These materials included mud, horse hair, wool, and straw. These organic materials were effective but had significant limitations, especially in terms of durability and insulating efficiency.
As the Industrial Revolution took hold, steam power became the dominant source of energy. This required the use of pipes, which needed to be insulated to prevent heat loss and reduce fire risks. Asbestos became one of the most common insulation materials until health concerns led to its ban by the 1970s.
The 1930s saw the introduction of fiberglass insulation. This was an effective insulator that had the advantage over asbestos of not being a health risk. Fiberglass is made from glass strands that trap air, which makes it an extremely effective insulator.
Throughout the 1940s and 1950s, another form of insulation came onto the market known as cellulose. This was a material that could be blown into walls and attics to insulate a home or building. Cellulose was an excellent insulator but also lacked the ability to get into all of the small nooks and crannies that are found in older homes.
In the 1960s, spray foam was introduced as a high-quality insulation that was much easier to install than traditional fiberglass or asbestos. It expanded to fill divots and corners, unlike blankets of fiberglass or asbestos that only covered level areas. Its easy installation and excellent insulating qualities quickly made it a popular choice for homes.
Cellulose
Insulation is a vital component of every home. It protects us from harsh weather elements while reducing energy costs and providing thermal comfort for its occupants. Throughout history, human ingenuity has pushed the boundaries of available materials to make shelters as efficient and comfortable as possible. As a result, the insulation industry is constantly evolving to meet the demands of advancing technology and sustainability principles.
Early civilizations used animal skins and fur, clay, straw, hay, and other natural materials to create a barrier between indoors and outside environments. These natural insulators reduce heat transfer and provide rudimentary temperature regulation.
Then, in 1838, French chemist Anselme Payen discovered and isolated cellulose. Cellulose is a linear, ribbon-shaped polymer of glucose molecules with b(1-4) glycosidic bonds between glucose units. This structure gives cellulose high tensile strength and resiliency. It is odorless, flavorless, hydrophilic, and insoluble in water.
Today, cellulose is an energy-efficient and environmentally friendly insulation option. It is manufactured from 75 to 85 percent ground-up recycled newsprint and sometimes with denim. It is available as loose-fill or blow-in, and it can be used in closed existing walls, new walls, unfinished attics, and unfinished basements. The primary drawback to cellulose is that it must be kept dry because it absorbs up to 20 percent of its weight in moisture. Moisture can cause it to sag and lose its ability to prevent air flow between the wall and framing.
Mineral Wool
It has a wide range of uses in masonry cavity walls and timber frame constructions and for roof spaces as well as under claddings such as curtain walls, spandrel panels, rainscreen facades and exterior insulation and finish systems (EIFS). Also known as glass wool, stone wool or rock wool it is a fibrous insulation manufactured from drawn out strands of melted and spun basic minerals – commonly from saltrock and slag, the stony waste matter separated from metals during smelting operations.
It is usually pressed into rigid batts that resemble fiberglass batting but offer a bit more stiffness and dimensional stability. Its inorganic nature makes it impervious to fire, resists water and is highly effective as a sound absorber.
Like cellulose, it offers good energy performance measures and lower emissions compared to conventional insulating materials. It is relatively inexpensive and can be used for wall and roof cavities, framed walls, and stud-partition walls. It can also be used in place of drywall and as a backing for claddings such as aerated concrete, precast slabs, and textured and plastered walls. Mineral wool typically uses a chemical binder to hold the fibres together. Historically, these binders have been made with volatile organic compounds (VOCs) that can off-gas into the building and negatively impact indoor air quality. However, this has been mitigated in recent years with a move toward low or no VOC binders.