The profession of window cleaning is the result of a synergistic relationship between two separate innovations of human civilization: Glass making and building construction. Both of which are the product of rich, long histories in their own right. To provide the context for this article, extremely brief overviews are given to set the stage and are by no mean intended to be complete.
Glass has long been a material used in human culture. Deep mysteries surround exactly which ancient culture became the first to combine sand, soda-line and ashes in high temperature to become glass. The ancient Roman historian Pliny suggested that Phoenician merchants first made glass in the region of Syria around 5000 BC. Archaeological evidence indicates the first man-made glass originated in Mesopotamia around 3500BC, although glass-making origins are also demonstrated in Egypt around the same period and is likely a result of the trading network between the two cultures.
The collapse of the Roman empire saw a decline in glass manufacturing techniques which did not really pick up again until the 13th century. The type of glass we see every day in windows and storefronts is called sheet glass and on March 25, 1902, Irving W Colburn patented the sheet glass drawing machine, making the mass production of glass for windows possible.
The first building to feature a glass curtain wall was Oriel Chambers in Liverpool, built in 1864, it was framed in iron and was five storeys tall. This innovation led to further developments, shifting away from load bearing masonry to a steel skeleton which supports the weight of the structure. The Home Insurance Building in Chicago at 138 ft and ten storeys was built in 1885 and is the world’s first skyscraper to use this technology. Less than fifty years later, the tallest building in the world, The Empire State Building was a stunning 1250 feet, 102 storeys with and has 6514 windows.
Workers of the trade are often by necessity required to be trouble shooters and innovators in their own right. As buildings continued to get taller, The challenge of safely cleaning the windows became an issue. Lugs or eye bolts were embedded in the building on each side of a window, cleaners then wore a belt similar to those used by electrical linemen and would climb out of the window and attach each end of the belt to the hooks. The window cleaner would lean back against the belt with his toes on ledges only a few inches wide and clean the window. Incredibly labour intensive and requiring large crews to complete the work, this method was quickly abandoned as rope descent systems began to appear.
Although abseiling, a technique used by mountain climbers dates back to 1876, the use and promotion of descenders for window cleaning was a by-product of the Vietnam War. Using a combination of ropes and descending equipment, a platoon could quickly and safely exit a helicopter to reach the ground below. Vets returning from Viet Nam who used these systems adapted them to the window cleaning industry.
Just as advancements in technology allowed for more efficient glass production and building construction, working from heights continues to get safer as well. Innovations in the industry including the bosun’s chair, descent & ascent systems, parapet clamps, swing stages, aerial lifts and water-fed poles contribute to a safer work environment. Also, regulatory bodies such as WCB develop safe work standards and oversee the industry while industry specific societies such as SPRAT provide recognized training and accreditation.