Roofing, by definition, is the covering of a structure, which includes all installations and materials required to support it on top of walls, giving protection from rain, sunlight, snow, wind, extreme temperatures, and high winds. A roof is usually a part of the outer building envelope. Structures that need extensive roof coverage are usually built in a tropical or desert climate. While roofs provide structural and protective cover for people and possessions, they also offer aesthetic beauty, privacy, and utility. Depending on the type of structure, the roof can also protect the contents from all types of weather elements.
Roofing materials come in many forms, but the most commonly used ones are shingles, tarps, slate, tiles, concrete, metal, and insulation. Each type of roofing material offers different advantages and drawbacks. For example, shingles are inexpensive, easy to install, require low maintenance, but may experience significant damage due to fire, animals, or storms. Tarps are lightweight and flexible, but can be easily punctured, crack, or break. Slate, tiles, and concrete all have the strength to withstand tremendous weight and weather conditions, while being highly durable and versatile.
The roofing structure, also known as a sheath, consists of two layers – the first is the underlying membrane, called the membrane sheathing, which provides protection from both precipitation and abrasion. A thin layer of asphalt shingles or metal is then installed on top of the sheath. Different types of asphalt shingles are available such as metal, wood, rubber, and many others. The thickness of the asphalt shingles, or asphalt layer, is a very important factor. A thicker asphalt shingle gives better protection from the weather elements, while a thinner shingle may be easier to replace should it become damaged.
After the asphalt shingles are installed, a clear top layer of roofing felt is laid directly above them. The purpose of this layer is to act as a waterproof layer to help seal in moisture. A water-resistant underlayment is then spread over the felt layer to strengthen it. The felt layer is also treated with a water repellent agent to prevent moisture from penetrating the roofing felt. It is recommended that the water-resistant underlayment be replaced every three years to ensure proper function and durability of the roof.
If the existing roof already needs repair or replacement, the metal flashing is first installed around the perimeter of the hole to create a watertight seal. Next, an acrylic braid sheet is attached to the flashing and securely stitched to the edges of the opening. Finally, the new roofing shingles are installed directly onto the acrylic braid, following the same steps previously described. This process is repeated for any number of holes in the existing roof, ensuring that each row of new shingles corresponds to the previous one.
Asphalt and clay tiles are the most durable roofing options, but they are dependent upon a number of factors. For instance, clay tiles do not have the same amount of wind resistance as asphalt shingles, so they may become damaged by heavy winds. Also, clay tiles are dependent upon the amount of sun that the roof receives. Asphalt roofs are highly dependable and weather resistant, but they are susceptible to becoming slick during a snow storm or strong thunderstorm. Newer types of clay tile are incorporating the use of silver or gold flakes to achieve a shiny, mirror like appearance, which reduces the amount of sunlight that passes through them.