50 Fun Facts About Roofing

Henry Reynolds of which city invented asphalt shingles, North America's most common roofing?

First used in 1903, they were in general use in parts of the US by 1911; by 1939 America was making 11 million squares a year.

In what year were asphalt shingles first used on a roof?

A National Board of Fire Underwriters campaign against wood shingles helped push them into the mainstream.

In 1897, what was first added to the surface of asphalt roofing to make it more durable?

Later granule experiments included mica, oyster shells, dolomite and fly ash; the underside gets talc or sand so shingles don't stick together in the bundle.

By 1882, what share of Britain's slate came from Wales?

The Penrhyn and Dinorwic quarries alone produced half of it, and the men worked in partnerships called 'bargains'.

Large-scale Welsh slate mining began in 1782 with the opening of which quarry near Bethesda?

It started as the Cae Braich y Cafn quarry in the Ogwen Valley and grew into one of the largest slate quarries in the world.

Slate splits into smooth flat sheets for roofing because of a property called what?

The same property makes it ideal for floor tiles and billiard tables; North Wales slate comes in many shades of grey and even purple and green.

A 2013 report estimated how many properties in the UK still had a thatched roof?

Most are long straw, combed wheat reed or water reed, and more than 80 percent of the water reed used is now imported.

How much well-managed reed bed does it take to produce enough water reed to thatch an average house?

Large reed beds have been rare in most of England since Anglo-Saxon times, which is why so much is imported from Turkey, Eastern Europe, China and South Africa.

The mansard roof is named after which 17th-century French architect who popularised it?

The tale that mansards dodged a French window tax is a myth: the tax was enacted in 1798, 132 years after Mansart died.

A gambrel roof, the classic American barn shape, has how many slopes on each side?

The Dutch call it a 'two-sided mansard roof', while in Europe the word mansard often means a gambrel.

Which shape is recommended in hurricane regions because it has no flat gable ends to catch the wind?

For hurricane country it also needs to be steep, at least 35 degrees, because wind over a shallow hip roof creates lift like an aeroplane wing.

The word 'dormer' comes from a Middle French word meaning what?

Dormer windows lit attic bedrooms; on church spires the slender version is called a lucarne.

In US roofing, a roof that rises 6 inches for every 12 inches of horizontal run has what slope?

The tables on a framing square show slope, not pitch, which is a common source of confusion on site.

What pitch does a flat roof have?

Every other roof is 'pitched'; even a flat adobe roof usually carries a very slight slope for run-off.

The strip of flashing below a chimney is still traditionally called what?

Builders' books were giving instructions on lead flashing by 1832, and the 1875 Notes on Building Construction shows methods still used today.

According to the Oxford English Dictionary, the word 'eaves' comes from an Old English word meaning what?

The Old English efes was singular, which is why 'eaves' now serves as both singular and plural.

Which people first brought rainwater gutter systems to Britain?

The technology was lost after they left and reintroduced by the Normans; the White Tower at the Tower of London had gutters.

Who patented 'indented or corrugated metallic sheets' in 1829, giving the world corrugated iron roofing?

Palmer was engineer to the London Dock Company; after his patent expired in 1843 corrugated galvanised iron became a worldwide favourite.

Overlapping tiles called imbrex and tegula covered the roofs of which ancient civilisations?

The flat tegula sat under the curved imbrex; the system is still recognisable in Mediterranean terracotta roofs.

In which country is Lerna's 'House of the Tiles', where thousands of Bronze Age terracotta roof tiles were found?

Clay tiles are thought to have been invented independently in Greece and China in the late Neolithic.

The first sports venue with a retractable roof was in which US city?

The now-demolished Civic Arena opened in 1961 for the Pittsburgh Civic Light Opera and later hosted the Penguins.

How many tiles cover the shells of the Sydney Opera House?

They come in glossy white and matte cream in a chevron pattern, made by Höganäs, a Swedish firm that mostly made tiles for paper mills.

The Sydney Opera House's roof tiles were manufactured in which country?

Architect Jørn Utzon was Danish; the building opened in 1973, 16 years after he won the design competition.

Almost 2,000 years after it was built, the Pantheon in Rome still holds what record?

The height to the oculus and the interior diameter are identical, 43 metres, so a perfect sphere would fit inside.

The Notre-Dame de Paris roof that burned in April 2019 was largely oak from which century?

The timbers were sheathed in lead; the stone vaults below largely contained the collapsing roof.

Who coined the term 'geodesic' for the dome design he popularised and patented in 1954?

He wasn't the original inventor; a planetarium dome, 'The Wonder of Jena', had opened in Germany in 1926.

Over decades, a copper roof weathers to which distinctive colour?

The verdigris patina is so prized that architects like Renzo Piano have specified pre-patinated copper to get it on day one.

According to historian Wolfgang Born, the onion dome originated where?

Umayyad-era mosaics show early bulbous domes; the shape is now most associated with Russian Orthodox churches.

The oldest surviving rooster-shaped weather vane, the Gallo di Ramperto, was made in which year?

It sits in a museum in Brescia; Pope Gregory I had called the cockerel 'the most suitable emblem of Christianity'.

The Tower of the Winds in ancient Athens carried a weather vane in the shape of which sea god?

The bronze figure held a rod that turned with the wind; the tower is one of the earliest known weather vanes.

Where does the name of the 'widow's walk', a railed rooftop platform on old coastal houses, supposedly come from?

In other towns they were 'captain's walks'; architecturally it is a variation of the Italianate cupola.

The New England saltbox house is named after its resemblance to what?

It is two storeys at the front and one at the back, so the rear roof slope is much longer than the front.

Which architect first used the V-shaped butterfly roof, on a 1930 holiday house in Chile?

The form became a mid-century icon when William Krisel and Dan Palmer put it on nearly 2,000 Palm Springs houses from 1957.

Why did the Houston Astrodome paint sections of its roof panes white in 1965?

The fix killed the natural grass, so the Astros played on green-painted dirt and in 1966 the dome got the first AstroTurf.

Domestic chimneys first appeared in large northern European dwellings in which century?

The Romans had drawn smoke from bakeries through wall tubes; England's earliest surviving example is at Conisbrough Castle.

A traditional Scandinavian sod roof sits on layers of which material laid over the roof boards?

Until the late 19th century it was the standard roof on rural log houses in Norway.

Which US city hall's green roof, planted as a microclimate experiment, is one of the country's best-known?

Chicago followed up with building codes that reward green roofs.

An ice dam forms where on a heated building's sloped roof?

Snow melts over the warm attic, runs down and refreezes at the cold overhang, backing water up under the shingles.

Modern timber roofs are mostly framed with pairs of common rafters or with what prefabricated components?

Trusses are fastened with metal connector plates; historic buildings used principal rafters or timber roof trusses instead.

Per the US Bureau of Labor Statistics, roughly how many people worked as roofers as of May 2022?

Roofing is ranked among the most dangerous construction trades because of falls and extreme heat.

In Australia, what is the tradesperson who builds a house's timber roofing frame called?

Australia has an estimated 15,000 roofers, with New South Wales the biggest market.

Wimbledon's Centre Court gained a retractable roof in which year?

It lets play continue in rain and into the evening, up to a council-imposed 11 pm curfew.

The 'shingle' in roof shingle is a corruption of a German word meaning what?

Historically shingles were called tiles, and outside the US the word still mostly means wooden ones.

Whose paintings suggested Fiddler on the Roof's title and inspired its original set design?

The writers had considered simply calling the musical Tevye.

The word 'roof' comes from Old English hrof, which also figuratively meant what?

English alone kept the word in a general sense; other Germanic languages use forms related to 'thatch'.

Which traditional thatching material is described as the most durable, lasting perhaps 40 years?

In many Asian countries, split bamboo stems laid alternately and overlapped serve as both structure and outer layer.

In the UK, what is the condition called when a slate roof's corroded fixing nails let slates slip?

A slate roof can last 75 to 150 years or more, but in the US it may cost as much as the rest of the house.

The stone arch or vault dominated major roof structures for about 2,000 years until which 1851 building?

Roman stone arches could span spaces up to 45 metres across before iron beams took over with the Industrial Revolution.

Which French cathedral's vast copper roof, oxidised to pale green, has been in place for hundreds of years?

Lead was more often used for church roofs and as flashing in valleys and around chimneys.

Which two North American cities are cited as requiring a minimum roof slope of 6 in 12 because of snow?

A pitch of 30 degrees helps steep roofs shed snow, as in Germany and Holland; Alpine chalets buck the trend with gentler stone roofs.