The Ancient Egyptians used it. So did the Ancient Romans. In the 1800’s, a guy wrote about it, sort of. By the Great Depression, there was a growing demand for it. In the mid 1970’s, medical science told us we were doing it wrong. Now, 21st century builders have to “go green” to earn green. And the future seems brighter (and more energy efficient than ever.) We’ve used cork, asbestos, glass, plastic, foam and even mud to do it. Yes, when you look at the history of insulation, in all its myriad forms, we can see just how far we’ve come.
The Ancient Egyptians used insulation to keep their desert homes and buildings cool, and their linen clothing warmer in the cooler winter months. They added papyrus linings to their loincloths and skirts to keep warm in winter. They built their homes of thick brick, designed to help keep out the sun’s scorching heat in summer.
The Ancient Greeks knew about asbestos, in fact they named it. They used it to dress their imported slaves, as well as for the wicks of their eternal temple flames, napkins and the funeral dress of kings. The material’s flame-resistant properties gave it a bit of a mystical appeal to the Greeks. They had a common name for it, too crysotile which means “gold cloth.” The Greeks were the first to go on record as noting that asbestos caused a “lung sickness” in the slaves who worked with it and wore it. The Greeks also knew how to insulae their homes, using cavity walls. The air trapped in between the inner and outer walls would act to help keep out the colder or hotter air, depending on the season.
Always on the look out for the next best thing, the Ancient Romans also dressed their slaves in asbestos cloth. They made tablecloths and napkins for restaurants and banquets out of asbestos cloth, throwing it into the fire between diners or courses to clean it of crumbs. The Romans were perhaps the ancient world’s most noted engineers, and they knew enough to build cavity walled structures, too. They learned to insulate their heated water pipes with cork from Spain and Portugal so that they could be placed under floors without fear of overheating the flooring.
The Vikings and other northern Europeans learned to insulate their homes with mud chinking, plastering it in the cracks between the logs or hewn boards of the buildings walls.. When mixed with horse or cattle dung and straw, the mud was known as daub, and was considered a stronger, better building material over plain old mud. They created clothing out of thick sheep’s wool, and may have even used cloth to line the interior walls of their homes.
Cloth came to be widely used in the Middle Ages among the wealthy as stone once again came into fashion for home building. These imposing stone structures tended to be drafty, damp and cold. Large ornately embroidered or woven tapestries would be hung on interior walls, partly to block out the drafts and partly to soak up the dampness. Rushes on the floors also helped to keep things a bit warmer underfoot.
During the Industrial Revolution, manufacturers turned once again to asbestos for their insulation needs. Steam-powered technology meant lots of hot pipes to carry the steam to where it was needed. These hot steam supply pipes could be made safer for workers by wrapping them in asbestos. With the invention of the steam locomotive, the demand for asbestos exploded. Suddenly, fireboxes, boilers, pipes and even boxcars and breaks were lined or wrapped in the heat retarding, flame-resistant fibers.
During the Great Depression, residents of the “Dust Bowl” of the US Southern Plains region attempted to insulate their homes from the choking dust storms by using strips of cloth coated in flour-based glue or paste. These could then be pasted over cracks around window and door frames to try and keep out the dust. City dwellers often did something similar with newspapers, stuffing them in cracks in window frames in hopes of keeping their frigid tenement apartments a bit warmer against winter’s chill.
Asbestos continued to be the main source of both industrial and residential insulation through the 19th and mid 20th centuries, though. World War II saw it being used in aircraft and ship production. In the 40’s and 50’s, mineral wool or rock wool started to overtake asbestos in popularity, however. Having been “discovered” in the 1870’s a safer manufacturing process led to its wider spread use among construction and industry.
The rediscovery in the mid-1970’s of asbestos’s harmful health effects signaled the death knell for asbestos materials in building construction. You’ll still find it keeping your automotive breaks and clutches cool, however, and crysotile is still being mined in some countries.
With the decline of asbestos, other forms of insulation had to be found and found quickly. Fiberglass insulation comes in various forms and is considered to be the “traditional” choice in home insulation. Styrofoam sheets and PVC wraps are now available. Concerns over the ecology and environment have led to the “discovery” of several forms of insulation considered to be more environmentally sound. Paper cellulose, recycled cotton denim and even sheep wool are being touted as the new wave in insulation. Imagine, cloth and wool as insulating materials? Perhaps we haven’t come that far after all!