Types of Roofs
Gabled roof. A gabled roof is perhaps the most iconic roof shape. This style of roof is the easiest and most cost-effective option for both roofers and homeowners.
Hipped roof. A variation on a gabled roof, a hipped roof is constructed with four sloping faces that all meet at the top of the roof. Hipped roofs are known for their strength, so they’re popular in regions that experience high winds and extreme winter weather.
Gambrel roof. Gambrel roofs are commonly seen on barns, but many homeowners choose this style due to the additional space it creates in the attic. Re-roofing a gambrel roof costs similar to re-roofing a gabled roof.
Combination roof. Popular in new construction, combination roofs typically include gables and hips. Mixing roof styles can lead to a complex roof with many high and low points, so waterproofing is very important to avoid leaks.
Flat roof. Flat roofs are most often used on commercial buildings, but they are becoming more popular in the residential market, especially on homes with a modern or contemporary architecture style. Installing a flat roof involves specialized knowledge and materials, so choose a contractor with adequate experience.
Parts of a Roof
Decking. Also referred to as sheathing, this is the first layer on top of the home’s rafters. Decking is typically made of plywood or oriented strand board (OSB) and is the material onto which the other layers of the roof are attached. Properly installed decking is essential to a sturdy roof.
Underlayment. Roofing underlayment is a thick, water-resistant material that helps protect the roof’s decking from moisture. Most residential roofs are constructed with underlayment made of a thick felt that has been impregnated with asphalt, but synthetic underlayments are growing in popularity.
Soffit and ridge vents. Properly venting a roof is vital to its longevity. In fact, if your roof has asphalt shingles, inadequate ventilation may void the shingle manufacturer’s warranty and cause the roof to fail prematurely. Soffit vents are located in the roof’s overhang, or what is often referred to as the roof’s eaves. Ridge vents are installed at the top of the roof. Used together, soffit and ridge vents allow air to enter the attic under the eaves and exit from the top of the roof. Due to limited ridge lengths, some homes require the use of turbine, or power, vents.
Fascia. Fascia is the horizontal piece of material at the end of a roof’s eaves. Wood is a common material for fascia board, but low-maintenance aluminum and synthetic options are gaining market share. When correctly installed together, soffit vents and fascia seal the roof and prevent pests from entering the attic while still allowing adequate airflow through the space.
Flashing. Flashing is an important part of waterproofing a roof. Usually made of metal, flashing prevents water from entering any small openings in the roof. Flashing is typically installed around dormer windows, skylights, vents, and chimneys.
Once the roof’s foundation is sturdy and secure, the final step is installing the outer covering. Shingles are popular, but there are many options.
Asphalt shingles. Asphalt shingles are known for their cost effectiveness and relative ease of installation. These shingles are available in a host of different colors. Laminated asphalt shingles are constructed with a fiberglass backer to increase durability.
Wood shakes and shingles. Wood roofs require consistent maintenance, but they can last longer than traditional asphalt shingle roofs. The most popular varieties of wood for wood shakes and shingles are cedar, redwood, and pine.
Metal. Metal roofs are growing in popularity because of their long lifespan. Metal roofs often carry a higher up-front cost than shingle roofs, but when installed properly, a metal roof is virtually maintenance-free and will never need replacement.
Slate, clay, and concrete. These heavy, durable roofing materials result in beautiful, low-maintenance roofs, but they do represent a significant financial investment. Most homes will require reinforced roof framing to accommodate the additional weight of these materials.
Membrane. If you decide on a flat roof, your roof will be covered by a flexible, tar-based or synthetic membrane instead of shingles. BUR, or built-up roof, is the traditional flat roofing system made of gravel and tar, while modified bitumen and EPDM are newer options.
Leaks. Most roof leaks are caused by failing or improperly installed flashing around vent pipes, skylights, or chimneys. Some roofers will use caulking to fix a leak, but this is usually a temporary solution; the leak can return and cause even bigger problems. In most cases, the flashing will need to be repaired or replaced to prevent future leaking.
Ventilation. Improperly vented roofs allow heat and moisture to build up in the attic, which can cause mold and mildew growth, rotting, and overheating. The ridge-and-soffit vent system is one of the least costly ventilation systems available, and it is very effective against the buildup of warm, moist air. It runs on the natural tendency of hot air to rise and creates a self-perpetuating ventilation system.
Waves in the roof. Normal settling of the house can cause slight deviations in the levels of the roof rafters, which can cause a wavy appearance. This is typically not a roof performance issue. You may see waves if new shingles were installed over an existing, improperly installed layer of shingles; in this case, a roofer must remove both layers and install new shingles. Rotted decking can also cause a wavy look, as can asphalt shingles that haven’t completely bonded or sealed. Damaged decking must be replaced, but time and warm weather will fix waves caused by shingles that have yet to fully adhere. The sun’s heat will soften the adhesive on the shingles and help them flatten and seal, eliminating the roof’s wavy appearance.
Roof work can be loud, so while it isn’t required, some people choose to leave the house until the project is done. Cover or remove items stored in the attic, and park your car on the street, not in the driveway. When the work is completed, the job foreman should do a final inspection to ensure nothing was missed by the installers. Debris can also easily fall into gutters, so ask the crew to check the gutters and downspouts for any hidden remnants.