The roof is a very important part of any house as it is the first line of defense against the elements. Whether you are designing from scratch or replacing an existing roof, some things to think about with roof system are the slope of the roof, the complexity of the roof (gables, hips, and valleys), material of the roof, and the surrounding environment.
Often times the slope of a roof is driven by the style of the house, but it can be affected by the environment and cost. Generally a steeper roof costs a little more, but can give more room inside. Also a high slope roof is used in areas that get a lot of snow, the steeper roof keeps the snow from accumulating on the roof that could cause structural failure. Lower slope roofs use less material and therefore can be a little cheaper. They are easier and safer to work on, but may require more maintenance, as leaves and debris can accumulate. A flat roof is a little different animal. They generally cost more due to the materials and system used to make it function properly.
The complexity of a roof refers to its shape, from a simple one plane shed to a roof that has hips, valleys, and dormers. Obviously the less complex the roof, the cheaper it is to frame and roof, some roofers charge per cut they have to do on site. Also each time the plane of the roof is interrupted (valley, dormer) is a potential place for water infiltration, although there are products and systems available that help minimize this risk. The amount the roof overhangs the sides of the house is another factor to consider. The cost and complexity increase as the overhang increases, but a larger overhang protects the siding and windows, prolonging their life. Also large overhangs can offer shading from the sun to help lower energy cost.
The most commonly used materials to choose from when it comes to cladding a roof are asphalt shingles, metal, and membrane. Asphalt shingles are probably the most common and the cheapest of the materials. They are easy to work with which is important when you have a complex roof. Also they are easy to repair. We always recommend keeping an extra pack of shingles when putting on new shingles so if a repair is needed the shingles match. Metal is the next most commonly used material. Metal is more expensive, but is more durable and can last much longer than shingles. Metal roofs are ideal for lower pitch roofs because the smooth finish allows debris to slide off. Metal is more difficult to work with on complex roofs and not as easy to repair. Membrane is one of a couple materials that come in a roll and are glued down. Membranes are most commonly used on flat roof systems, but can also be useful in unusual situations where the other two won’t work. This material requires some special skills and tools to install and repair correctly.
Metal and membrane roofs are ideal for rainwater catchment systems.
Lighter colored roofing material can enhance reflectivity and reduce energy costs.
The environment the structure is exposed to is another factor to consider when thinking about a roof. Things like weather, snow, and the amount of trees over the structure can all affect the performance of a roof. It is important to maintain your roof by, keeping it clear of debris, checking for damage and wear, and checking around any penetrations to assure flashing and sealants are in good shape. The roof is a critical component to any building, and it is essential that the right choices are made to assure that the roof performs properly.
