The roof is arguably the most important structure in any building. Its basic role has not changed substantially over thousands of years - it shelters a building's interior and its occupants from the elements and rounds out a building's aesthetic.
Indeed, without a roof, a building is simply just 4 walls. Whilst the basic structure has remained similar, however, the materials and the methods used in roofing have evolved substantially throughout history. Below, we'll examine how roofing solutions have evolved and how the methods and materials of today compare with yesteryear.
In the early years of commercial roofing, clay tiles, wood and slate were the most popular materials used in many homes. Slate is amongst the most durable 'old-school' roofing material; many slate roofs built hundreds of years ago are still standing to this day.
Both slate and clay are also incredibly fire-resistant, which was a major benefit in the years before central heating when fires were more common. Wood, meanwhile, was common due not only to its flexibility and the wealth of wood available but because it was easy to transport.
Whilst wood, slate, and clay were used predominantly in the early years of commercial roofing
, in the mid-19th century, roofers began to utilise metal systems, particularly in the US, where red-painted tin roofs started to become commonplace.
The turn of the 20th century, meanwhile, brought with it the practice of rolling asphalt over shingle roofing to achieve a more durable finish and clear look. Asbestos was also used during this period due to its affordability, its heat-resistance, its sound-absorbency and its incombustibility.
However, it was later discovered in the 20th century that asbestos is actually a toxic material, with thousands of people falling gravely ill due to a respiratory disease dubbed 'asbestosis.'
During the 1960s and 1970s, the mass production of composite metals and polymers meant that roofing designs became more ambitious and flexible, particularly for commercial roofing designs.
In recent years, options such as glass and solar panel roofing
have also become standard and the 20th century also saw the development and introduction of guttering, flashing, and drainpipes, which all had a part to play in the evolution of how roofs were designed, constructed, and installed.
The construction of domestic roofs changed very little in the years before the 20th century. Although timbers were generally cut by machine instead of by hand, construction didn't alter dramatically until the 1900s, when the more typical domestic roofing that we're all familiar with now began to take shape.
This type of sloped roofing saw ceiling joists supporting the ceiling itself and acting as a tie to the rafters, with a binder often added to prevent joist deflection
. The beauty with this type of roof is it could be adapted comfortably for larger roofs with the addition of a purlin to prevent larger rafters from sagging. The eaves of the rafters were also designed to either overhang or to finish flush with the wall, with guttering added for rain runoff.
Most roofs built between 1900 and 1940 followed this basic template, but after the war, with thousands of houses damaged and a shortage of building materials, new techniques had to be created. These techniques reduced the amount of timber needed, which did away with the need for internal load-bearing walls.
In the 1960s, with materials back in supply and the western world bouncing back after WWII, the trussed rafter design became popular as one of the best roof designs
of the 20th century. Trussed rafters are prefabricated so they cut down on construction time significantly.
Indeed, you might often even see the entire roof being constructed on the ground before being lifted into place via crane. The timbers of trussed rafters are held together by machine-pressed plates and the timber itself is treated to prevent rot. The trussed rafter design is so popular that it still remains a standard to this day and perhaps marks the peak of domestic roofing solutions