A roof is essentially the biggest cover of a structure, which includes all structures and materials needed to support it on top of poles, providing protection from sunlight, rain, wind, extremes of temperatures, and external threats such as ice and high wind. A roof covers the most exposed parts of a building and therefore becomes the largest component of its total construction budget. In terms of actual roofing costs, a basic roof can cost anywhere between five thousand and ten thousand dollars, depending on the roof design and materials used. A more elaborate roof design may go up to thirty-five thousand dollars or more, depending on the roof materials, complexity, and location.
There are many different types of roofs, including flat, sloped, pitched, contoured, and hipped roofs. Flat roofs are the cheapest to install. Flat roofs have few, if any, valleys or inclined sections. Flat roofs are typically made of timber, although metal or composite roofs are also available.
Flat roofs usually have two to four levels with regular spacing along the length of the flat roof. Flat roofs slope towards the slope or crest of a hill, but not always, as this could cause excess moisture to accumulate and be drained away. Sometimes, flat roofs slope gradually towards the road and this causes water accumulation behind the roof. When this happens, water can cause damage to the surrounding building materials and infrastructure, as well as being a health hazard for inhabitants of the building. Flat roofs may also slope away from their junction with the ridge or other topography, sometimes leading to water accumulation and eventually in bad weather conditions. Some flat roofs may include a design feature that allows snow to slip easily off the roof, leading to water accumulation on the sides of the roof and even causing a slip and fall.
The pitch of a roof, which is the angle of slope at its highest point, ranges from flat to steeply sloping. The most steeply sloped roofs are generally the most widely used. The steep pitch is referred to as “teardrop” pitch and has been the most popular. The flat pitch is referred to as “rampant pitch” and has only recently started to become widely used.
Lean-to roofs are a type of “utility roof”. The roof lies between the house and the main structure, often with a gap between the two structures. Lean-to roofs are most commonly used for garages, driveways and entrances. A narrow gap is left between the house and the garage, while the driveway and the lean-to have no space between them. This type of roof requires a great deal of slope to be installed correctly, often requiring two slopes of at least 15 degrees.
Pitched roofs are a specific type of roofing construction that is best suited to smaller buildings and for low-sloped areas. The roofs are pitched diagonally, with each pitch being equal to one half of the wall area of the house. The pitch cannot be more than one-third of the wall height. Pitched roofs offer various options, including single slope, double slope, chimney and attic pitched roofs. These roofs may also feature runoff drains. Pitched roofs are an economical way to provide roof coverage in very tight spaces.