The Evolution of Roofing Materials
Although the history of roofing goes back to the earliest part of human history, roofing technology in the 20th century took massive leaps forward in helping to keep houses at a comfortable temperature and protected from natural disasters or weather. This was due to an improved understanding of chemistry and more efficient manufacturing methods, which allowed the first composite shingles to be produced.
The First Asphalt Shingles
Composite shingles, as the name suggests, are made from a mishmash of different materials, as opposed to earlier stone and wood shingles. The first were made of felted fabric covered in tar, but in 1903, Henry M. Reynolds of Grand Rapids, Michigan came out with the first asphalt shingles, made from bitumen (a form of petroleum) combined with shards of quartz, brick, slate, or similar minerals. Not only were asphalt shingles cheaper to make than their predecessors, but they better protected homes from ultraviolet light and kept more heat from escaping during the winter, a particularly important factor considering central heating was not widespread at the time.
As asphalt shingles became more popular, innovations like the multitab strip shingle were introduced. These sheets were larger than were previously possible, making installation easier and cheaper. New models with tab variations also made it easier for shingles to resist strong winds, a boon for those in areas prone to storms. Other models were made to mimic the look of thatch.
From Asphalt to Solar Panels
As time has gone by, more innovations in roofing have come. In the 1990s, DOW Chemical Company introduced TPO (Thermaplastic PolyOlefin) roofing. This method employed membranes of ethylene propylene rubber in a single seamless structure to keep out the heat by reflecting it away from the home, while also protecting the house from ozone and algae. Unlike asphalt shingles, TPO can be recycled for use in other products, and even used as a fuel that burns extremely cleanly.
Solar or photovoltaic roofing has recently become popular in regions that get a lot of sunlight. Unlike large panel generators, these roofs gather solar energy while looking like normal shingles. The generated electricity can supplement the house's everyday use. Because the energy is fed back into the grid when more energy is being produced than used, it is possible to financially make up for days without sun. Solar roofing is more expensive than conventional roofing and takes more to maintain, but the technology is certainly advancing rapidly.
A Return to Nature and Origins
Another environmentally friendly roofing option besides solar panels is “living” roofs. These are made by placing soil and vegetation in a waterproof covering. Living roofs release oxygen into the environment around a building and help to keep it cool through water runoff. Green roofs are expensive to maintain and as such their adaptation has been slow, but as technology improves they will likely become more popular.
In some European countries, homeowners are returning to more environmentally friendly roofing materials like thatch, made of straw or sod. While they may not provide all the protection from the elements, in regions with more mild climates they may prove a viable option.
Roofing material technology is always improving. Who knew roof shingles could one day allow you to power your home!