Roof is the upper most part of a building’s structure designed to provide protection from the rain, snow, and other nature’s elements. Roofs around the world vary in the type, or shape of the roof, steepness, and type of roofing materials used. There are two ways in which the roof can be constructed; one piece impermeable shell such as PVC roofing membrane, glass or metal dome, or it can be constructed from many different water resistant pieces such as asphalt shingles, ceramic tiles, or natural slates that divert the rain water away from permeable gaps in the roof.

Roofs of the world

In places with little rainfall, roofs tend to have a minimum roof pitch and are predominantly flat. In places with a lot of rain and snowfall, roofs tend to have a steeper pitch, which helps divert the rain water and shed the snow away from the roof. Throughout the world, roofs are built from both natural and man-made materials. Natural building materials such as wood and vegetation are used to build up roofs. In Asia, many roofs are constructed from bamboo. In Africa, roofs can be a covered with banana leaves and other types of vegetation. In the Middle East, many roofs are built from the solid concrete slabs, and are predominantly flat. In America, the most common type of roofing material is asphalt shingles, an oil based roofing product. Cedar shake, slate, sheet metal, and clay tiles are among other less common roofing materials used in the U.S. for pitched roofs.

From thatch to green roof gardens and solar roofs.

Thatch roofs

In Europe, especially in United Kingdom thatched roofs, made from waterproof vegetation, provide protection for thousands of homes. Even today some well to do people in England, choose to install thatched roofs to attain the traditional look and style. Thatched roofs have been used for thousands of years because thatch or plant vegetation was a readily available, and abundant building material. Thatched roofs are considered sustainable because they are made from from the naturally growing leaves. In modern day thatched roofs have lost their prominence due to the high expense of labor required to install a thatched roof. Another problem with thatched roofs is that thatched roofs roofs are predisposed to catching fire, especially in areas with drier climates.

Bamboo roofs

In oriental cultures, bamboo is used for the construction of the roofs. Bamboo is a fast growing and abundant building material that combines flexibility and strength. Bamboo roofs are characterized by the cave in effect in the middle of the roof due to be bending of the bamboo beams used in the construction of the roof.

Concrete roofs

Concrete roofs are common in Middle East countries such as Egypt, Iraq, and others. Concrete roofs are predominantly flat, and often contain parapet walls to provide protection for the people may choose to spend their time on the rooftop. This is common in hot Middle Eastern countries where people may sometimes sleep on the rooftop to find the relief from the heat at night. Concrete roofs are generally several inches thick, and are constructed from one piece concrete slab. Concrete roofs are extremely heavy and require strong outside walls and beams to hold the concrete slab. Some companies install concrete roofs in the United States in hurricane prone areas. Concrete roofs provide excellent hurricane protection and are best when the building is made from a one piece shell integrating foundation walls and the roof and reinforced with steel beams acting as a skeleton for the cured of concrete.

Asphalt shingle roofs

Asphalt shingle is a petroleum based product made from fiberglass mat saturated in asphalt to attain water resistant properties. Then, the top coating of asphalt is applied and sand granules are added. Asphalt shingle is not a waterproof product and relies on pitch to divert water away from the roof. Typically minimal pitch of 4 inches for every 12 inches of run is required for the asphalt shingle roof. The average expected lifespan of an asphalt shingle roof is 17 years. Asphalt shingle roof performs better in more temperate and cooler climates. In hotter climates, sun and thermal shock due to rapidly changing temperatures shortens the life of an asphalt shingle roof. Asphalt shingle roofs are at least expensive to install, but short lifespan and lock of proper recycling methods account for frequent re roofing, expensive tear offs and environmental degradation due to disposal to the landfills.

Cedar shake roofing

In the past, cedar shake roofs used to be made from a longer lasting wood, and would actually last longer on the roof. Today cedar shake roofs don’t last as long as they used to, and aside from aesthetic appeal provide little benefit to cost return.

Ceramic and clay tiles

Made from ceramic and clay the styles are heavy weighing 6 pounds per square foot. This requires a specially reinforced roofing structure. Ceramic tiles provide Spanish tile roof look and can last anywhere from 20 to 100 years depending on quality of the material.

Slate roofs

Natural slate is a pristine and long lasting roofing material that conveys durability and style. Slate roofs have been used throughout the world for hundreds of years. Slate tiles vary in thickness and can last anywhere from 50 200 years. Slate tile is heavy weighting 8 pounds per square foot, it requires special roof construction reinforcement. Slate roofs are very expensive, but they are made from a natural stone, and can last for the lifetime of the building.

Sheet metal

Roofs made from rolled steel and aluminum sheets are lightweight environmentally friendly and last a long time. Steel roofs are coated with aluminum and zinc alloy and provide effective and reliable protection. Steel shingle roofs, and standing-seam roofs made from steel and aluminum can last 50 years and longer. Their costs falls somewhere in the middle that in the cost of asphalt shingle and slate roofs. The high end sheet metal roofing product featuring zinc and copper can last as long as 100 years and do not require coating. Stainless steel and titanium roofs are also available to building owners were not limited by the budget. Coated metal roofs reflect solar radiant heat keeping the building cooler and providing energy savings. Some of the metal roofing systems are cool-roof rated, which means that their energy efficient and have a high degree of solar reflectance and thermal emissivity. Cool roofs reduce the use of cooling energy in warm seasons, which reduces air conditioning load and mitigates the effects of heat islands in the big cities. Metal roofs are considered green because they are ecologically and environmentally safe, and can be fully recycled at the end of their useful life.

Solar roofing

Photovoltaic solar technology has given birth to innovative solar shingle roofing products and the development of roof mounted solar panels that can be added to the rooftops of residential and commercial buildings. Roofs integrated standing-seam solar panels are the latest in the advances of solar roofing industry. Solar roofs generate electricity and can actually pay for themselves when installed on the roof that gets a lot of sun exposure.

Green roof tops

Green roofs help mitigate the effects of urban heat islands associated with roofs that capture solar radiant heat and emit it back to the surrounding environment creating heat island of fact. Green roofs feature vegetation on the rooftop that provides excellent installation, which keeps the building cool. Fresh air and beauty are other benefits of green roofs. Green roof can can be constructed in two ways; built up turf and added vegetation with carefully designed irrigation, water collection and drainage systems. A less expensive way to build a green roof is to use green roof containers that can be arranged on the rooftop of the building.

Roof construction

And the U.S. Most roofs are built over attic spaces that act as insulation and noise barrier. Roofing underlayment serves as an additional level of installation and water barrier protection. A proper roof ventilation of the attic must be incorporated into the construction of the roof. This will help move with the roof insulation and help prevent the rotting of the roof deck. Properly insulated and adequately ventilated roof will keep your building cooler, last longer, and help prevent ice dams. Roofing beams are constructed from timber, or steel frame. The type and weight of the future roof needs to be considered in the construction of the roofing frame including roof beams trusses that will carry the weight of the roof.

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Roofing materials