Storm Damage Restoration Process

Tile used to keep out rain

See also: Roof shingle

Roof tiles are overlapping tiles designed mainly to keep out precipitation such as rain or snow, and are traditionally made from locally available materials such as clay or slate. Later tiles have been made from materials such as concrete, glass, and plastic.

Roof tiles can be affixed by screws or nails, but in some cases historic designs utilize interlocking systems that are self-supporting. Tiles typically cover an underlayment system, which seals the roof against water intrusion.^[1]

Categories

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There are numerous profiles, or patterns, of roof tile, which can be separated into categories based on their installation and design.

Shingle / flat tiles

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One of the simplest designs of roof tile, these are simple overlapping slabs installed in the same manner as traditional shingles, usually held in place by nails or screws at their top. All forms of slate tile fall into this category. When installed, most of an individual shingle's surface area will be covered by the shingles overlapping it. As a result of this, flat tiles require more tiles to cover a certain area than other patterns of similar size.^[2]

These tiles commonly feature a squared base, as is the case with English clay tiles, but in some cases can have a pointed or rounded end, as seen with the beaver-tail tile common in Southern Germany.

Imbrex and tegula

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The imbrex and tegula are overlapping tiles that were used by many ancient cultures, including the Greeks, Romans, and Chinese. The tegula is a flat tile laid against the surface of the roof, while the imbrex is a semi-cylindrical tile laid over the joints between tegulae.

In early designs tegula were perfectly flat, however over time they were designed to have ridges along their edges to channel water away from the gaps between tiles.^[3]

Mission / Monk and Nun tiles

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Similar to the imbrex and tegula design of tile, mission tiles are a semi-cylindrical two-piece tile system, composed of a pan and cover. Unlike the imbrex and tegula both the pan and cover of Mission tile are arched.

Early examples of this profile were created by bending a piece of clay over a worker's thigh, which resulted in the semi-circular curve. This could add a taper to one end of the tile.

Pantiles / S tiles

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Pantiles are similar to mission tiles except that they consolidate the pan and cover into a single piece. This allows for greater surface area coverage with fewer tiles, and fewer cracks that could lead to leakage.

These tiles are traditionally formed through an extruder. In addition to the S-shaped Spanish tiles, this category includes the Scandia tiles common to Scandinavia and Northern Europe.

Interlocking tiles

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Dating to the 1840s, interlocking tiles are the newest category of roofing tile and one of the widest ranging in appearance.^[4] Their distinguishing feature is the presence of a ridge for interlocking with one another. This allows them to provide a high ratio of roof area to number of tiles used. Many distinct profiles fall into this category, such as the Marseilles, Ludowici, and Conosera patterns.^[5]

Unlike other types of tiles, which can in some cases be produced through a variety of methods, interlocking tiles can only be manufactured on a large scale with a tile press.

In many cases interlocking tile is designed to imitate other patterns of tile, such as flat shingles or pantiles, which can make it difficult to identify from the ground without inspecting an individual tile for a ridge.^[6]

History as a vernacular material

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The origins of clay roofing tiles are obscure, but it is believed that it was developed independently during the late Neolithic period in both ancient Greece and China, before spreading in use across Europe and Asia.^[7]

Europe

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Greece

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Fired roof-tiles have been found in the House of the tiles in Lerna, Greece.^[8][9] Debris found at the site contained thousands of terracotta tiles which had fallen from the roof.^[10] In the Mycenaean period, roof tiles are documented for Gla and Midea.^[11]

The earliest roof tiles from the Archaic period in Greece are documented from a very restricted area around Corinth, where fired tiles began to replace thatched roofs at two temples of Apollo and Poseidon between 700 and 650 BC.^[12] Spreading rapidly, roof tiles were found within fifty years at many sites around the Eastern Mediterranean, including Mainland Greece, Western Asia Minor, and Southern and Central Italy.^[13] Early Greek roof-tiles were of the imbrex and tegula style.^[14] While more expensive and labour-intensive to produce than thatch, their introduction has been explained by their greatly enhanced fire-resistance which gave desired protection to the costly temples.^[15]

The spread of the roof-tile technique has to be viewed in connection with the simultaneous rise of monumental architecture in Ancient Greece.^{[citation needed]} Only the newly appearing stone walls, which were replacing the earlier mudbrick and wood walls, were strong enough to support the weight of a tiled roof.^[16] As a side-effect, it has been assumed that the new stone and tile construction also ushered in the end of 'Chinese roof' (Knickdach) construction in Greek architecture, as they made the need for an extended roof as rain protection for the mudbrick walls obsolete.^[17]

A Greek roof tile was responsible for the death of Molossian Greek king Pyrrhus of Epirus in 272 BC after a woman threw one at the king's head as he was attacking her son.^[18]

Roman Empire

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Roof tiles similar to Greek designs continued to be used through the reign of the Roman Empire. They were a common feature in Roman cities, despite the fact that a single tile would often cost the equivalent of 1.5 day's wages. Tiles were commonly used as improvised weapons during citizen uprisings, as they were one of few such weapons available to city-dwellers of the time.^[19]

Roman imbrex and tebula roofs generally avoided the use of nails and were instead held in place through gravity, it is possible that this was one of the reasons their tile was found on low pitched roofs.^[20]

The Romans spread the use and production of roofing tile across their colonies in Europe, with kilns and tile-works constructed as far west and north as Spain and Britain. Early records suggest that brick and tile-works were considered under the control of the Roman state for a period of time.^[21]

Northern Europe

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It is believed that the Romans introduced the use of clay roof tile to Britain after their conquest in AD 43. The earliest known sites for the production of roof tile are near the Fishbourne Roman Palace. Early tiles produced in Britain followed the Roman imbrex and tebula style, but also included flat shingle tiles, which could be produced with less experience.^[21]

For a while after the dissolution of the Roman Empire, the manufacture of tile for roofs and decoration diminished in Northern Europe. In the twelfth century clay, slate, and stone roofing tile began to see more use, initially on abbeys and royal palaces. Their use was later encouraged within Medieval towns as a means of preventing the spread of fire. Simple flat shingle tiles became common during this period due to their ease of manufacture.^[22]

Scandinavian roof tiles have been seen on structures dating to the 1500s when city rulers in Holland required the use of fireproof materials. At the time, most houses were made of wood and had thatch roofing, which would often cause fires to spread quickly. To satisfy demand, many small roof-tile makers began to produce roof tiles by hand. The Scandinavian style of roof tile is a variation on the pantile which features a subdued "S" shape reminiscent of an ocean wave.^[23]

In Britain, tiles were also used to provide weather protection to the sides of timber frame buildings, a practice known as tile hanging.^[24] Another form of this is the so-called mathematical tile, which was hung on laths, nailed and then grouted. This form of tiling gives an imitation of brickwork and was developed to give the appearance of brick, but avoided the brick taxes of the 18th century.^[25]

Asia

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China

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Clay roof tiles are the main form of historic ceramic tilework in China, due largely to the emphasis that traditional Chinese architecture places on a roof as opposed to a wall.^[26] Roof tile fragments have been found in the Loess Plateau dating to the Longshan period, showing some of the earliest pan and cover designs found in Asia.^[7] During the Song dynasty, the manufacture of glazed tiles was standardized in Li Jie's Yingzao Fashi.^[27] In the Ming dynasty and Qing dynasty, glazed tiles became ever more popular for top-tier buildings, including palace halls in the Forbidden City and ceremonial temples such as the Heavenly Temple.

Chinese architecture is notable for its advancement of colored gloss glazes for roof tiles. Marco Polo made note of these on his travels to China, writing:

The roof is all ablaze with scarlet and green and blue and yellow and all the colors that are, so brilliantly varnished that it glitters like crystal and the color of it can be seen from far away.^[26]

Japan

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Japanese architecture includes Onigawara as roof ornamentation in conjunction with tiled roofs. They are generally roof tiles or statues depicting a Japanese ogre (oni) or a fearsome beast. Prior to the Heian period, similar ornaments with floral and plant designs "hanagawara" preceded the onigawara.

Onigawara are most often found in Buddhist temples. In some cases the ogre's face may be missing.^[28]

Korea

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In Korea the use of tile, known as giwa, dates back to the Three Kingdoms period, but it was not until the Unified Silla period that tile roofing became widely used. Tiles were initially reserved for temples and royal buildings as a status symbol.

The designs used on giwa can have symbolic meanings, with different figures representing concepts such as spirituality, longevity, happiness, and enlightenment. The five elements of fire, water, wood, metal and earth were common decorations during the Three Kingdoms period, and during the Goryeo dynasty Celadon glaze was invented and used for the roof tiles of the upper class.

Many post-war Korean roofs feature giwa and a common ornamental symbol is the Mugunghwa, South Korea's national flower.^[29]

India

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Neolithic sites such as Alamgirpur in Uttar Pradesh provide early evidence of roof tiles.^[30] They became more common during the iron age and the early historic period during the first millennium BCE.^[31] These early roof tiles were flat tiles and rounded or bent tiles, a form that was widespread across the Ganga Valley and the Indian Peninsula, suggesting that it was an essential architectural element of this period.^[31] This early form of roof tiles also influenced roof tiles of neighboring Nepal and Sri lanka.^[31]

Metal roof tiles made of gold, silver, bronze and copper are restricted to religious architecture in South Asia. A notable temple with golden roof tiles is the Nataraja temple of Chidambaram, where the roof of the main shrine in the inner courtyard has been laid with 21,600 golden tiles.^[32]

Southeast Asia

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Tapered flat roof tiles have been used in Thailand, Laos and Cambodia since at least the 9th or 10th century CE, with widespread adoption after the 14th century, commonly to roof traditional Buddhist temple architecture.^[33] These shingle tiles have flat elongated bodies with a bent upper end for hooking at the roof and a pointed lower end.^[33]

In Indonesia, approximately 90% of houses in Java island use clay roof tile.^[34] Traditionally, Javanese architecture use clay roof tiles.^[35] However, it was not until late 19th century that houses of commoners in Java and Bali started using roof tiles.^{[citation needed]} The Dutch colonial administration encouraged the usage of roof tiles to increase hygiene.^{[citation needed]} Before the mass usage of roof tiles in Java and Bali, commoners of both of islands used thatched or nipa roof like the inhabitants of other Indonesian islands.^{[citation needed]}

In the Philippines, aside from various thatching methods, a native roof tiling technique is the kalaka which uses halved bamboo sections fitted together.^[36] During the Spanish colonial era of the Philippines, colonial-era bahay na bato architecture (which mixes native and Spanish architecture) also extensively used the Spanish-style Monk and Nun tiles, known natively as teja de curva.^[37]

North America

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Roof tiles were introduced to North America by colonizers from Europe, and typically were traditional designs native to their original country.

Pieces of clay roof tile have been found in archeological excavations of the English settlement at Roanoke Colony dating to 1585, and in later English settlements in Jamestown, Virginia and St. Mary's, Maryland. Spanish and French colonists brought their designs and styles of roofing tile to areas they settled along what are now the southern United States and Mexico, with Spanish-influenced tile fragments found in Saint Augustine, Florida, and both Spanish and French styles used in New Orleans, Louisiana.

Dutch settlers first imported tile to their settlements in what are now the Northeastern United States, and had established full-scale production of roofing tiles in the upper Hudson River Valley by 1650 to supply New Amsterdam.

Clay roof tiles were first produced on the West Coast at the Mission San Antonio de Padua in 1780. This Spanish-influenced style of tile remains in common use in California.

One notable site of roof tile production was Zoar, Ohio, where a religious sect of German Zoarites formed a commune in 1817 and produced their own roofs in a handmade German beaver-tail style for several decades.^[38]

From the 1700s through early 1800s, clay roofing tile was a popular material in colonial American cities due to its fire-resistance, especially after the establishment of urban fire-codes.

In spite of improving manufacturing methods, clay tile fell out of favor within the United States around the 1820s, and cheaper alternatives such as wood shingle and slate tile became more common.^[39]

Post-vernacular history

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Clay tiles

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Beginning around the mid-1800s, expanding industrial production allowed for more efficient and large-scale production of clay roofing tile. At the same time, increasing city growth led to rising demand for fireproof materials to limit the danger of urban fires, such as the Great Chicago Fire of 1871.

These conditions combined to bring a significant expansion in the use of roof tile, with a shift from regional and hand-produced tile to patented and machine-made tile sold by large-scale companies.^[40]

Gilardoni tiles

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The Gilardoni brothers of Altkirch, France were the first to develop a functional interlocking roof tile.^[41]

The Gilardonis' design marked a significant shift in the design of roofing tile. Prior to this tile most roofing tile profiles could be hand made without the need for large-scale machines, but the new interlocking tiles could only be produced with a tile press and were more cost effective than comparable vernacular styles. Through the rest of the 19th century many companies began refining and developing other versions of interlocking tiles.^[41]

The Gilardoni brothers began making their design in 1835 and took out a patent on their first design of interlocking clay tile in 1841, with a new design patented ten years later. The Gilardonis shared their patent with six other French tile manufacturers between 1845 and 1860, contributing greatly to the spread of interlocking tile usage throughout France and Europe. Their company built additional factories and continued to operate until 1974.^[41][42]

Marseilles tiles

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Another popular early interlocking tile pattern was the Marseilles design invented by the Martin Brothers in Marseille, France as early as the 1860s. The Marseilles tile pattern is distinguished from other designs by its diagonal notches on its side rebate, as well as the teardrop-shaped end of its middle-rib.^[41]

While the Martin Brothers invented the design, its widespread use was more due to the pattern's adoption and international production after its original patent expired. The Marseilles tile was widely exported, especially in European colonies in South and Central America, Africa, and Australia.^[41]

French-manufactured Marseilles tiles were imported to Australia by 1886 and New Zealand by 1899.^[43][44] Many New Zealand railway stations were built with them, including Dunedin.^[45][46] Large scale production of Marseilles tiles by Wunderlich began in Australia during war-time import shortages in 1916.^[43] From 1920, factories at Pargny-sur-Saulx exported tiles to England.^[47] By 1929 Winstone were making them at Taumarunui, in a tile works established about 1910, which was replaced by Plimmerton in 1954.^{[48][49][50][51]}

Ludowici tiles

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In 1881 Wilhelm Ludowici developed his own interlocking tile, an improvement upon the earlier designs which incorporated a double-rebate on the side, double head-fold at the top of the tile, and a strategically designed surface pattern for repelling water and melting snow from the top of the roof. Unlike other designs, Ludowici included his tile's central rib for functional reasons rather than aesthetic.^[41]

Ludowici's design was mass produced in Germany and later the United States by the Ludowici Roof Tile company, who advertised the pattern as French tile.^[52]

Many tiles found in the Mangalore region of India are derived from or made in this pattern. Clay roof tiles had been produced in the region since missionary Georg Plebst set up the first factory at Mangalore, Karnataka, India, in 1860 after finding large deposits of clay by the banks of the Gurupura and Netravati rivers. The initial tiles they produced were similar to the Gilardoni brothers' design, but later tiles adopted Ludowici's pattern. Over the years ten companies produced Mangalore tiles, which were exported around the Indian Ocean and subcontinent.^[53]

Conosera tiles

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The Conosera tile was developed by George Herman Babcock in 1889, and was unique due to its diagonally interlocking structure and design allowing for more installation flexibility than other interlocking tile designs. Babcock designed the pattern with towers and spires in mind, since his design significantly reduced the number of graduated tile sizes needed to roof a cone.^[54]

Conosera was initially manufactured and sold by the Celadon Terra Cotta Company of Alfred, New York. After a merger formed the Ludowici-Celadon Company in 1906 the group continued to produce Conosera tile for special orders.^[55]

Concrete tiles

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The earliest known concrete tiles were developed in the 1840s by Adolph Kroher. While visiting Grassau, Bavaria, Kroher learned about locals' use of regional minerals to create stucco and began to experiment with the material, developing a diamond-shaped interlocking pattern of concrete tile which became one of his company's primary profiles. He also manufactured a concrete pantile similar to the Scandinavian style of clay tile.

In order to reduce the high shipping cost for his tile, Kroher adopted a 'do-it-yourself' method of tile manufacture for some time, where he sold a supply of cement and the necessary tools for a home-builder to create their own tiles. This had the disadvantage that cement was prepared by amateurs and did not always have consistent or correct mixing preparation.

Concrete tiles became more widespread in Germany over the next few decades after manufacturers such as Jörgen Peter Jörgensen and Hartwig Hüser began producing interlocking and overlapping designs.^[56]

The concrete tile industry grew and spread internationally through the early 20th century, driven by its cheapness to produce at scale.^[57] Researchers considered concrete tile inferior to clay tile, largely due to its fundamental weaknesses of porosity and color impermanence.^[58][59]

Glass tiles

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Glass tiles, also referred to as skylight tiles, are used as accessories alongside clay roof tiles. These were first developed in the 1890s and designed to allow light into spaces roofed with interlocking tiles, such as warehouses and factories.^[41]

It is uncommon for a roof to be completely covered in glass tiles however there are a few exceptions, such as on the tower of Seattle's King Street Station.^[60]

Plastic tiles

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Plastic tiles, marketed as composite or synthetic tiles, became available towards the end of the 20th century. Their exact invention date is unclear, but most became available around the year 2000.^[61][62]

Plastic tiles are generally designed to imitate slate or clay tiles, and achieve their color through synthetic dyes added to the plastic. They are produced through injection molding.^[63]

Solar tiles

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Dow Chemical Company began producing solar roof tiles in 2005, and several other manufacturers followed suit. They are similar in design to conventional roof tiles but with a photovoltaic cell within in order to generate renewable electricity.

In 2016 a collaboration between the companies SolarCity and Tesla produced a hydrographically printed tile which appears to be a regular tile from street level but is transparent to sunlight when viewed straight on.^[64] Tesla later acquired SolarCity and the solar shingle product was described as "a flop" in 2019.^[65] The company later dropped their claim that their tiles were three times as strong as standard tiles, without specifying why they backed away from the claim.^[66]

Tile roofs require fittings and trim pieces to seal gaps along the ridge and edges of a roof.

Ridge pieces are laid upon the very top ridge of a roof, where the planes of a pitched roof meet. This section is usually parallel to the ground beneath.

The tiles which cover this section of the roof have to direct water away from the top of the ridge and onto either side of the pitched roof below.^[67]

Terminals are ridge tile fittings that are used as an endcap on the gable end or apex of a roof. In some cases these can be highly decorative, taking the form of a sculpture or figurine, while in others they can be more practical and architectural in nature.

Graduated roof tiles are tiles designed to "graduate" in size from top to bottom, with smaller tiles at the top and larger ones at the bottom. They are necessary when installing a tile roof on a tower, cone, or dome and need to be specially designed for each roof they are used on for effective functionality.

An antefix is a vertical block which terminates and conceals the base of a mission, imbrex and tegula, or pantile roof.^[68]

They are commonly a fixture of Greek and Roman tile roofs and can often be highly ornamental.

Tiles, often ornamental, applied beneath the eave of a roof structure. Found in temple architecture of Sri Lanka, among other locations.

The durability of roofing tiles varies greatly based on material composition and manufacture. Durability is directly related to three factors; a resistance to chemical decomposition, a low porosity, and a high breaking strength.

Clay and slate tiles are stable materials and naturally resistant to chemical decomposition, however plastic composite tiles and concrete tiles will experience inevitable decay over time. As a result of this, high-quality clay and slate tiles have a proven lifespan of over 100 years, whereas synthetic and concrete tiles usually have a practical lifespan of 30–50 years.^[69][70][71] In the case of synthetic plastic tiles, this is purely an estimation since the oldest products on the market date to around 2000.^[62] The main cause of plastic tile decay is exposure to ultraviolet radiation, which weakens the chemical bonds of the material and causes the tiles to become more brittle over time.^[72][73]

A common effect seen in cement roof tiles is efflorescence, which is caused by the presence of free lime within concrete. This lime reacts with water to form calcium hydroxide, which creates a chalky deposit on the outside of the tiles. While not detrimental to the strength or durability of the cement tiles, this effect is considered unappealing.^[74]

Tiles with a porosity above 2% allow for intrusion and absorption of water, which can be detrimental in climates with freeze-thaw conditions or salt air intrusion. During a freeze-thaw cycle, water that infiltrates a tile will see volume expansions of 9% upon freezing, which exerts pressure within any pores it manages to enter and causes cracks to grow. When the ice melts, water spreads further into those cracks and will then apply more stress to them upon the next freeze.^[75] A similar effect can be seen in areas near the ocean that experience salt-air intrusion, which can lead to salt crystal permeation and expansion.^[76]

Clay tile porosity can range greatly depending on quality of production, but some manufacturers can achieve less than 2% moisture absorption. Concrete roof tiles tend to feature around 13% moisture absorption, which requires periodic resealing every 3–7 years to avoid critical failure.^[77][71] The inherent porosity of cement requires that cement tiles are made very heavy and thick, as a result they have continuously been one of the heaviest roofing materials in the market.^[78]

It is commonly believed that a porous clay tile can be waterproofed through the application of a glaze; however studies have shown that this is not the case. If a clay body contains significant pores, water will permeate them over time regardless of exterior coating.^[79]

The breaking strength of clay tiles can vary greatly by manufacturer, depending on a combination of factors such as their firing temperature, specific clay composition, and length of the firing cycle. Despite the common conception of clay tiles being fragile, higher-grade manufacturers produce tiles with breaking strengths ranging from 700 to 1500 pounds.^[80]

The breaking strength of plastic roof tiles varies greatly depending on temperature. Unlike ceramics or metals, plastics have glass transition temperatures that fall within the range of winter temperatures, often resulting in them becoming extremely brittle during colder periods.^[81]

Clay roof tiles historically gained their color purely from the clay that they were composed of, resulting in largely red, orange, and tan colored roofs. Over time some cultures, notably in Asia, began to apply glazes to clay tiles, achieving a wide variety of colors and combinations.

Originally, most color variation on matte clay tiles was caused by variation in kiln firing temperature, kiln atmospheric conditions, and in some cases reductive firing. Many producers have shifted away from this process since low firing temperatures typically result in a higher porosity and lower breaking strength.

Engobes are now commonly used to replicate the appearance of historic firing variation, using a thin colored ceramic coating which chemically bonds to the tile to provide any range of matte colors to the fired tiles while allowing consistent firing conditions. Glazes are used when a shinier gloss appearance is desired. Like their clay base, both engobes and glazes are fully impervious to color fading regardless of UV exposure, which makes them unique among artificial colorants.^[82]

The color of slate tiles is a result of the amount and type of iron and organic material that are present, and most often ranges from light to dark gray. Some shades of slate used for roofing can be shades of green, red, black, purple, and brown.^[83]

Cement tiles typically are colored either through the use of a pigment added to the cement body, or through a concentrated slurry coat of cement-infused pigment on the outside of the tiles. Due to the simple production process and comparatively low firing temperature, cement tiles fade over time and often require painting to restore a "new" appearance.^[84]

Plastic tiles are colored through the incorporation of synthetic dyes added to them during molding.^[63] As a result of their reactive chemical composition they can suffer degradation from UV rays and fade after a few years of use.^[85]

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  Frost on interlocking roof tiles in Britain
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  Underside of mission tile roof in Brazil, installed without underlayment or understructure
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  Slate tile roof in Norway
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  Modern tile press in Europe
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  Interlocking tile designed to look like pantile
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  Gloss blue roof tiles in Japan
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  Tile rooftops seen in Dubrovnik, Croatia

• Covering (construction)

Wikimedia Commons has media related to Roof tiles.

• Technical note on peg tile restoration work

Overlapping plates for covering a roof

This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "Roof shingle" – news · newspapers · books · scholar · JSTOR (January 2014) (Learn how and when to remove this message)

A roof’s shingles are a roof covering consisting of individual overlapping elements. These elements are typically flat, rectangular shapes laid in courses from the bottom edge of the roof up, with each successive course overlapping the joints below. Shingles are held by the roof rafters and are made of various materials such as wood, slate, flagstone, metal, plastic, and composite materials such as fibre cement and asphalt shingles. Ceramic roof tiles, which still dominate in Europe and some parts of Asia, are still usually called tiles. Roof shingles may deteriorate faster and need to repel more water than wall shingles. They are a very common roofing material in the United States.

Etymology and nomenclature

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Look up Schindel in Wiktionary, the free dictionary.

Shingle is a corruption of German Schindel meaning a roofing slate.^[1] Shingles historically were called tiles, and shingle was a term applied to wood shingles,^[1] as is still mostly the case outside the US.

Shingles are laid in courses, usually with each shingle offset from its neighbors. The first course is the starter course and the last being a ridge course or ridge slates for a slate roof. The ridge is often covered with a ridge cap, board, piece, or roll,^[2] sometimes with a special ridge vent material.

Overview

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Roof shingles are almost always highly visible and so are an important aspect of a building's aesthetics in patterns, textures and colors. Roof shingles, like other building materials on vernacular buildings, are typically of a material locally available. The type of shingle is taken into account before construction because the material affects the roof pitch and construction method: Some shingles can be installed on lath where others need solid sheathing (sheeting) on the roof deck. All shingle roofs are installed from the bottom upward beginning with a starter course and the edge seams offset to avoid leaks. Many shingle installations benefit from being placed on top of an underlayment material such as asphalt felt paper to prevent leaks even from wind driven rain and snow and ice dams in cold climates. At the ridge the shingles on one side of the roof simply extend past the ridge or there is a ridge cap consisting of boards, copper, or lead sheeting. An asphalt shingle roof has flexible asphalt shingles as the ridge cap. Some roof shingles are non-combustible or have a better fire rating than others which influence their use, some building codes do not allow the use of shingles with less than a class-A fire rating to be used on some types of buildings. Due to increased fire hazard, wood shingles and organic-based asphalt shingles have become less common than fiberglass-based asphalt shingles. No shingles are water-tight so the minimum recommended roof pitch is 4:12 without additional underlayment materials.^[3]

Asphalt shingles

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Left: Example of faster asphalt shingle wear along eaves due to channeled water running down the roof. Right: Severe shrinkage resulting in tearing away of entire tabs. Note the exposed nail heads. Water running down the roof can seep around the nails into the interior space.

Main article: Asphalt shingle

In the United States, fiberglass-based asphalt shingles are by far the most common roofing material used for residential roofing applications. In Europe, they are called bitumen roof shingles or tile strips, and are much less common.^[4] They are easy to install, relatively affordable, last 20 to 60 years and are recyclable in some areas. Asphalt shingles come in numerous styles and colors.^[5]

The protective nature of paper and fiberglass asphalt shingles primarily comes from the long-chain petroleum hydrocarbons, while wood shingles are protected by natural oils in the cellulose structure. Over time in the hot sun, these oils soften and when rain falls the oils are gradually washed out of the shingles. During rain, more water is channeled along eaves and complex rooflines, and these are subsequently more prone to erosion than other areas.

Eventually the loss of the oils causes asphalt shingle fibers to shrink and wood shingles to rot, exposing the nail heads under the shingles. Once the nail heads are exposed, water running down the roof can seep into the building around the nail shank, resulting in rotting of underlying roof building materials and causing moisture damage to ceilings and paint inside.

Wood shingles

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Two basic types of wood shingles are called shingles and shakes. Wood shakes are typically longer and thicker than wood shingles. The main difference is in how they are made, with shingles always being sawn and shakes normally being split, at least on one side.^[6] A wood shake is often more textured, as it is split following the natural grain of the wood rather than sawn against it like the shingle. Untreated wood shingles and shakes have long been known as a fire hazard and have been banned in various places, particularly in urban areas where exterior, combustible building materials contribute to devastating fires known as conflagrations. Modern pressure-impregnated fire retardant treated wood shakes and shingles can achieve a Class B fire rating, and can achieve a Class A rating when used in conjunction with specially designed roof assemblies.^[7]

The use of wooden roof shingles has existed in parts of the world with a long tradition of wooden buildings, especially Scandinavia, and Central and Eastern Europe. Nearly all the houses and buildings in colonial Chiloé were built with wood, and roof shingles were extensively employed in Chilota architecture.

Slate shingles are also called slate tiles, the usual name outside the US. Slate roof shingles are relatively expensive to install but can last 80 to 400 years depending on the quality of the slate used, and how well they are maintained. The material itself deteriorates only slowly, and may be recycled from one building to another.

The primary means of failure in a slate roof is when individual slates lose their peg attachment and begin to slide out of place. This can open up small gaps above each slate. A secondary mode of failure is when the slates themselves begin to break up. The lower parts of a slate may break loose, giving a gap below a slate. Commonly the small and stressed area above the nail hole may fail, allowing the slate to slip as before. In the worst cases, a slate may simply break in half and be lost altogether. A common repair to slate roofs is to apply 'torching', a mortar fillet underneath the slates, attaching them to the battens. This may apply as either a repair, to hold slipping slates, or pre-emptively on construction.

Where slates are particularly heavy, the roof may begin to split apart along the roofline. This usually follows rot developing and weakening the internal timbers, often as a result of poor ventilation within the roof space. An important aspect to slate roofs is the use of a metal flashing which will last as long as the slates. Slate shingles may be cut in a variety of decorative patterns and are available in several colors.

Flagstone shingles are a traditional roofing material. Some stone shingles are fastened in place but some simply are held by gravity, so the roof pitch cannot be too steep or the stones will slide off the roof. Sandstone has also been used to make shingles.

• 
  Slate roofers guild emblem as an ornament made with slate roof shingles, Meerbusch, Germany. Note the hip shingles act as a ridge cap.
• 
  A typical flagstone roof in Kastanitsa, Greece.
• 
  A dry laid stone roof in Switzerland

Fibre cement shingles are often known by their manufacturer's name, such as Eternit or Transite. Often, the fiber in the cement material was asbestos, the use of which has been banned since the 1980s, for health reasons. The removal of shingles containing asbestos requires extra precautions and special disposal methods.

Metal shingles are a type of roofing material that offers the appeal of traditional shingles, such as wood, tile, and slate, while providing high fire resistance and durability. They are crafted from durable heavy-gauge aluminum and designed to emulate the classic appearance of traditional slate, cedar shingles, and other materials. Metal shingles are extremely fire resistant, so are used in fire prone areas.^[8]

Plastic has been used to produce imitation slate shingles. These are lightweight and durable, but combustible. Also, they are very lightweight and are one of the cheapest shingles to have installed.^[9]

Cedar shingles are resistant to rot and commonly available in lengths of 18 and 24 inches (460 and 610 mm). These fade gradually from natural wood colored to a silver-like tone. Types include hand-split resawn shakes, tapersplit shakes or tapersawn shakes.

Composite or synthetic shingles are a relatively new type of shingle material that are made from a blend of materials, including asphalt, fiberglass, and other polymers. These shingles are designed to mimic the look of natural materials such as wood, slate, or clay and aim to increase the durability, strength, and resistance to weather elements relative to these natural materials. Some examples of manufacturers of synthetic or composite roof shingles are DaVinci Roofscapes or Unified Steel.

Rubber shingle roofs are typically made from 95% recycled material from a variety of sources including recycled tires. They last twice as long as asphalt shingles but are about twice the price as asphalt. They are more quiet than most roofs, hail resistant, and a high wind rating if there is a tongue and groove fitting at the front edge of the rubber shingle design.^[10][11]

• Roof tiles
• Metal roof
• Roof cleaning
• Shingle style
• Solar shingle
• Asphalt shingle
• Shingles

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Roofer

Roofers working on a bungalow in Brompton, Quebec
Occupation
Occupation type	Vocational
Activity sectors	Construction
Description
Competencies	Heights, patience, steady hand, ability to read plans, physically strong
Education required	Apprenticeship
Fields of employment	Construction
Related jobs	Carpenter, Electrician, Plumber, Welder

A roofer, roof mechanic, or roofing contractor is a tradesperson who specializes in roof construction. Roofers replace, repair, and install the roofs of buildings, using a variety of materials, including shingles, single-ply, bitumen, and metal. Roofing work includes the hoisting, storage, application, and removal of roofing materials and equipment, including related insulation, sheet metal, vapor barrier work, and green technologies rooftop jobs such as vegetative roofs, rainwater harvesting systems, and photovoltaic products, such as solar shingles and solar tiles.^[1][2]

Roofing work can be physically demanding because it may involve heavy lifting, climbing, bending, and kneeling, often in extreme weather conditions.^[1] Roofers are also vulnerable to falls from heights due to working at elevated heights. Various protective measures are required in many countries. In the United States these requirement are established by the Occupational Safety and Health Administration (OSHA) to address this concern.^[3][4][5] Several resources from occupational health agencies are available on implementing the required and other recommended interventions.^[6][7][8]

According to data from the U.S. Bureau of Labor Statistics (BLS), as of May 2022^[update], there were 129,300 individuals working as roofers in the construction industry. Among that population, a majority of roofers (93%; 119,800) were contractors for Foundation, Structure, and Building Exterior projects.^[9][10] In terms of jobs outlook, it is predicted that there will only be a 2% increase in job growth from 2022 to 2032 in the United States. Approximately 12,200 openings are expected each year in this decade. Most of the new jobs are likely to be offered to replace roofers who retire or transition out of the trade.^[1]

In Australia, this type of carpenter is called a roof carpenter and the term roofer refers to someone who installs the roof cladding (tiles, tin, etc.). The number of roofers in Australia was estimated to be approximately 15,000. New South Wales is the largest province with an 29% market share in the Australian Roofers industry (4,425 companies). Second is Victoria with 3,206 Roofers (21%).^[11]

In the United States and Canada, they're often referred to as roofing contractors or roofing professionals. The most common roofing material in the United States is asphalt shingles. In the past, 3-tab shingles were used, but recent trends show "architectural" or "dimensional" shingles becoming very popular.^[12]

Depending on the region, other commonly applied roofing materials installed by roofers include concrete tiles, clay tiles, natural or synthetic slate, single-ply (primarily EPDM rubber, PVC, or TPO), rubber shingles (made from recycled tires), glass, metal panels or shingles, wood shakes or shingles, liquid-applied, hot asphalt/rubber, foam, thatch, and solar tiles. "Living roof" systems, or rooftop landscapes, have become increasingly common in recent years in both residential and commercial applications.^[13][14]

Roles and responsibilities of roofing professionals include:^[1]

• Assessing the roof system and components (may include decking and structural components)
• Determining the proper roofing system for the building
• Installing roof system components according to manufacturer’s specifications
• Repairing the roof system
• Maintenance of the roof system

Beyond having common duties such as replacing, repairing, or installing roofs for buildings, roofers can also be involved in other tasks, including but is not limited to:

• Seal exposed heads of nails or screws using roofing cement or caulk to avert possible water infiltration
• Tailor roofing materials to accommodate architectural elements such as walls or vents
• Align the installed materials with the roof's edges to ensure a proper fit
• Apply various roofing materials such as shingles, asphalt, metal, etc., to render the roof impervious to weather conditions
• Establish roof ventilation mechanisms to regulate airflow and control temperature fluctuations
• Set up moisture barriers or insulation layers to improve the roof's thermal performance
• Dismantle the current roof systems to make ways for repairs or new installations
• Substitute impaired or decaying joists or plywood to maintain the roof's structural integrity
• Assess roof dimensions to assess the necessary amount of required materials
• Conduct evaluations on problematic roofs to determine the most effective repair approach

Roofing is one of the most dangerous professions among construction occupations since it involves working at heights and exposes workers to dangerous weather conditions such as extreme heat.^[15] In the United States as of 2017, the rate of fatalities from falls among roofers is 36 deaths per 100,000 full-time employees, ten times greater than all construction-related professions combined.^[16] In the United States, the fatal injury rate in 2021 was 59.0 per 100,000 full-time roofers, compared to the national average of 3.6 per 100,000 full-time employees.^[17] According to the U.S. Bureau of Labor Statistics, roofing has been within the top 5 highest death rates of any profession for over 10 years in a row.^[18] For Hispanic roofers, data from 2001–2008 show fatal injuries from falls account for nearly 80% of deaths in this population, the highest cause of death among Hispanics of any construction trade.^[19][20]

A major contributing factor to the high fatality rates among roofers in the United States is the nature of the craft which requires roofers to work on elevated, slanted roof surfaces. Findings from qualitative interviews with Michigan roofing contractors also found hand and finger injuries from handling heavy material and back injuries to be some of the more common task/injury combinations.^[21]

Ladder falls contribute to the rates of injury and mortality. More than half a million people per year are treated for fall from ladder and over 3000 people die as a result.^[22] In 2014 the estimated cost annual cost of ladder injuries, including time away from work, medical, legal, liability expenses was estimated to reach $24 billion.^[22] Male, Hispanic, older, self-employed workers and those who work in smaller establishments, and work doing construction, maintenance, and repair experience higher ladder fall injury rates when compared with women and non-Hispanic whites and persons of other races/ethnicities.^[23]

Ladders allow for roofers to access upper level work surfaces. For safe use, ladder must be inspected for damage by a competent person and must be used on stable and level surfaces unless they are secured to prevent displacement.^[3]

Nearly every industrialized country has established specific safety regulations for work on the roof, ranging from the use of conventional fall protection systems including personal fall arrest systems, guardrail systems, and safety nets.

The European Agency for Safety and Health at Work describes scenarios of risk (fall prevention, falling materials, types of roofs), precautions, training needed and European legislation focused on roof work.^[6] European directives set minimum standards for health and safety and are transposed into law in all Member States.

In the United States, OSHA standards require employers to have several means of fall protection available to ensure the safety of workers. In construction, this applies to workers who are exposed to falls of 6 feet or more above lower levels.^[3][24] In the United States, regulation of the roofing trade is left up to individual states. Some states leave roofing regulation up to city-level, county-level, and municipal-level jurisdictions. Unlicensed contracting of projects worth over a set threshold may result in stiff fines or even time in prison. In some states, roofers are required to meet insurance and roofing license guidelines. Roofers are also required to display their license number on their marketing material.

Canada's rules are very similar to those from the U.S., and regulatory authority depends on where the business is located and fall under the authority of their local province.

In 2009, in response to high rates of falls in constructions the Japanese Occupational Safety and Health Regulations and Guidelines amended their specific regulations. In 2013 compliance was low and the need for further research and countermeasures for preventing falls and ensuring fall protection from heights was identified.^[25]

The United Kingdom has no legislation in place that requires a roofer to have a license to trade, although some do belong to recognized trade organizations.^[26]

The purpose of a PFAS is to halt a fall and prevent the worker from making bodily contact with a surface below. The PFAS consists of an anchorage, connectors, body harness and may include a lanyard, deceleration device, lifeline or suitable combination of these.

Beyond these mandatory components of the PFAS, there are also specific fall distances associated with the functioning of the arrest system. Specifically, there is a total fall distance that the PFAS must allow for to assist the worker in avoiding contact with the ground or other surface below. The total fall distance consists of free fall distance, deceleration distance, D-ring shift, Back D-ring height, and Safety margin. In addition to the fall distance requirements for each component of the PFAS, the anchorage of the PFAS must also be able to support a minimum 5,000 pounds per worker.^[4]

OSHA regulations have several requirements. The free fall distance, to the distance that the worker drops before the PFAS begins to work and slows the speed of the fall, must be 6 feet or less, nor contact any lower level. The deceleration, the length that the lanyard must stretch in order to arrest the fall must be no more than 3.5 feet.^[4] The D-ring shift, the distance that the harness stretches and how far the D-ring itself moves when it encounters the full weight of the worker during a fall, is generally assumed to be 1 foot, depending on the equipment design and the manufacturer of the harness. For the back D-ring height, the distance between the D-ring and the sole of the worker's footwear, employers often use 5 feet as the standard height with the assumption that the worker will be 6 feet in height, but because the D-ring height variability can affect the safety of the system, the back D-ring height must be calculated based on the actual height of the worker. The safety margin, the additional distance that is needed to ensure sufficient clearance between the worker and the surface beneath the worker after a fall occurs, is generally considered to be a minimum of 2 feet.^[3]

A fall restraint system is a type of fall protection system where, the goal is to stop workers from reaching the unprotected sides or edges of a working area in which a fall can subsequently occur. This system is useful where a worker may lose their footing near an unprotected edge or begin sliding. In such a case, the fall restraint system will restrain further movement of the worker toward the unprotected side or edge and prevent a serious fall. Although fall restraint systems are not explicitly defined or mentioned in OSHA's fall protection standards for construction,^[24][4] they are allowed by OSHA as specified in an OSHA letter of interpretation last updated in 2004.^[27] OSHA does not have any specific requirements for fall restraint systems, but recommends that any fall restraint system be capable of withstanding 3,000 pounds or at least twice the maximum predicted force necessary to save the worker from falling to the lower surface.^[3] There are no OSHA specifications on the distance from the edge the restraint system must allow for a falling worker, and although a likely very dangerous practice, the OSHA letter of interpretation states that as long as the restraint system prevents the employee from falling off an edge, the employee can be restrained to "within inches of the edge."^[27]

Guardrail systems serve as an alternative to PFAS and fall restraint systems by having permanent or temporary guardrails around the perimeter of the roof and any roof openings. OSHA requires the height of the top of the rail to be 39-45 inches above the working surface. Mid-rails must be installed midway between the top of the top rail and the walking/working surface when there is no parapet wall at least 21 inches high. Guardrail systems must be capable of withstanding 200-pounds of force in any outward or downward direction applied within 2 inches of the top edge of the rail.^[3][24]

Safety net systems use a tested safety net adjacent to and below the edge of the walking/working surface to catch a worker who may fall off the roof. Safety nets must be installed as close as practicable under the surface where the work is being performed and shall extend outward from the outermost projection of the work surface as follows:^[4]

^[4]

Safety nets must be drop-tested with a 400-pound bag of sand, or submit a certification record prior to its initial use.^[4]

Warning lines systems consist of ropes, wires, or chains which are marked every 6 feet with high-visibility material, and must be supported in such a way so that it is between 34 and 39 inches above the walking/working surface.^[4] Warning lines are passive systems that allow for a perimeter to be formed around the working area so that workers are aware of dangerous edges. Warning lines are only permitted on roofs with a low slope (having a slope of less than or equal to 4 inches of vertical rise for every 12 inches horizontal length (4:12)).^[28] In the context of roofing fall protection, warning line systems may only be used in combination with a guardrail system, a safety net system, a personal fall arrest system, or a safety monitoring system. The warning line system must be erected around all sides of the roof work area.^[4]

Safety monitoring systems use safety monitors to monitor the safety of other workers on the roof. Safety monitors must be competent to recognize fall hazards. The safety monitor is tasked to ensure the safety of other workers on the roof and must be able to orally warn an employee when they are in an unsafe situation.^[4]

Multi-layered approaches to fall prevention and protection that use the hierarchy of controls can help to prevent fall injuries, incidents, and fatalities in the roofing industry.^[7][8] The hierarchy of controls is a way of determining which actions will best control exposures. The hierarchy of controls has five levels of actions to reduce or remove hazards – elimination, substitution, and engineering controls are among the preferred preventive actions based on general effectiveness.

Resources are available to assist with the implementation of fall safety measures in the roofing industry such as fall prevention plans,^[23][29] a ladder safety mobile application,^[30] infographics and tipsheets,^[31] toolbox talks,^[32] videos and webinars,[1] and safety leadership training.[2] Many of these resources are available in Spanish and additional languages other than English. The recommended safety measures are described next.

In terms of job outlooks, it is predicted that there will only be an 1% increase in job growth from 2021 to 2032. The job openings (15,000) are expected to replace roofers who will retire or transition out of the trade.^[9]

Solar Roof installation is one of the fastest growing trends in the roofing industry due to the nature of solar roofs being environmentally friendly and a worthwhile economic investment. Specifically, solar roofs have been found to allow homeowners to potentially save 40-70% on electric bills depending on the number of tiles installed.^[33] The US federal government has also begun incentivizing homeowners to install solar roofs with potential eligibility for 30% tax credit on the cost of a solar system based on federal income taxes.^[34]

Across 14 researched markets, roofing contracting companies have reported that they have received more frequent calls regarding potential metal roof installations. For instance, one company used to receive 5-6 calls in total regarding metal installations but recently, they have received 5-6 calls weekly for inquiries regarding metal roof installations.^[35]

• Domestic roof construction
• Roof cleaning
• Flat roof
• Membrane roofing
• List of commercially available roofing materials
• Prevention through design

• Stop Construction Falls training and other resources from the Center for Construction Research and Training
  • Construction Toolbox Talks
  • Resources in Spanish and Additional Languages
• Construction Fatality Assessment and Control Evaluation (FACE) database, from the National Institute for Occupational Safety and Health and the Center for Construction Research and Training.
• Introduction to working at height safely from the Health Safety Executive, UK.
• Video NAPO: Working at height.
• Health and safety in roof work, from the Health Safety Executive, UK.
• Ladder safety resources from the National Institute for Occupational Safety and Health.
• You can prevent falls! from the Public Health Agency of Canada.
• Prevent Construction Falls from Roofs, Ladders, and Scaffolds, from the National Institute for Occupational Safety and Health.
• Roofing guidelines and recommendations, National Roofing Contractors Association.
• Education and Training Course Catalog, National Roofing Contractors Association.
• Occupational Employment and Wage Statistics, US Bureau of Labor Statistics.
• Infographics and Tipsheets. The Center for Construction Research and Training.

Wikimedia Commons has media related to Roofers.