Roofing is an exciting and challenging form of building construction. Roofers build, repair, and replace a wide variety of practical roofs.
The basic structure of a house or building’s roof is a frame of rafters or prefabricated trusses. The sheathing is then fastened to the rafters or trusses.
While the roof of a house may look like an insignificant covering that protects the inside from precipitation, there is far more to it than meets the eye. It has an internal structure, often called a truss, that creates a skeleton for the rest of the roof to build on top of. A few different types of trusses are used in the framing of a roof, and the type will determine the ability to add a loft or attic space later on, as well as ceiling height options for rooms inside.
The most common and familiar kind of roof structure is a gable roof, which has two planes of sloping walls that meet at a peak in the center, called a ridge. There is a gap where the rafters meet at the ridge, and this is covered with ridge tiles to help prevent rainwater from getting in through that space.
A more complicated roof structure is a lattice truss, which has wood strips on the outer side of the joists to hold up the shingles or tiles. A lattice roof can also have skylights to allow natural light into rooms below.
Another option for a roof is a rafter-beam truss, which has rafters based on the walls and a central joist, called the collar beam, to support them. This joist can be set higher than the joists around it, which can give a vaulted or tray ceiling appearance in certain rooms.
Other parts of a roof include drip edges, flashing and sheathing. Sheathing is a layer of material placed over the joists to provide additional insulation, as well as fire resistance and water protection.
Roof Deck
Just as the foundation is your home’s structural backbone, your roof deck (also known as sheathing) provides a solid base for the rest of your roof. The flat, sturdy sheets go over the rafters and joists of your roof framing, and from there, roofers secure all the other components that protect your home from the weather (like leak barriers and shingles).
Traditionally, roof sheathing was made from planks of wood, but today, most new homes are built with sheet sheathing. This is made from a flat, rectangular material that can be either plywood or OSB, and it comes in varying thicknesses, depending on the span of your rafters.
When constructing a new home, we typically use sheathing made from structural panels like plywood or OSB, because they help to transfer lateral loads from the roof plane to the walls of your house. We also offer sheathing made from solid wood tongue and groove boards if you’re building a custom home or have a preference for an exposed ceiling, but these don’t provide the same level of lateral load stability as panel sheathing.
If your home has old plank decking, it might be time to replace it. Water stains on interior walls or rafters, a drooping roofline, or curling or buckling shingles are all telltale signs that you need to have your decking replaced, and the sooner the better to stave off further damage. If you’re building a new house or doing a reroofing project, we recommend choosing either 3/8″ CDX plywood or 7/16″ OSB for your sheathing. Both are strong, durable, and cost-effective. They also meet code requirements for moisture protection.
Underlayment
A layer of underlayment protects the wood boards that make up your roof deck. This is important, since water can infiltrate a home’s structural wood, which leads to rot, mildew, mold and other problems. It also helps to prevent moisture from becoming trapped under shingles, which can lead to the formation of ice dams and a host of other issues.
Typically made from either asphalt-saturated felt or synthetic materials, roof underlayment acts as an extra barrier to prevent water that rises during a rainstorm from infiltrating the roof structure and into your home. In addition, it provides an additional insulation layer and reduces condensation that can contribute to roof damage, poor energy efficiency and even health issues for occupants.
While a variety of underlayment options exist, traditional felt underlayment is still common and meets most building code requirements. It is generally available in 15- and 30-pound thicknesses for different types of roofing pitches. Felt can be fastened using staples or nails, though in high-wind areas and with synthetic underlayment, plastic caps are often used because they offer better wind resistance and help to prevent leakage through holes created by the fasteners.
Synthetic underlayment is more resistant to fungal growth, less likely to wrinkle and has superior water resistance than felt. It’s lightweight and easier for workers to work with, reducing physical strain on them and allowing the installers to get a job done faster. It’s available in a wide range of colors to match or complement the color of your roof shingles, and it’s often used under premium designer, architectural and performance shingles.
If you live in a cold climate, it’s recommended that an ice barrier underlayment be installed. This is a self-adhering, waterproof underlayment that helps to limit the flow of melt-water back up under shingles, which could cause ice dams and other water damage.
Roofing Materials
Choosing the right roofing material is one of the most important decisions you’ll make when building or restoring a home. It has a big impact on the style of your roof, as well as the durability and energy efficiency of your home. You’ll also want to consider environmental friendliness, cost and local code requirements when selecting your roofing materials.
Roofing materials vary widely, from natural products like thatch and slate to manufactured options like asphalt shingles and metal tiles. They’re designed to protect a home from the elements, and a good quality roof will help keep your family comfortable and safe.
Low Slope Materials
Many types of roofing materials are suitable for use on low-sloped buildings, including single-membrane systems like EPDM, PVC or TPO and corrugated galvanised iron (also called Corro) or steel coated with a coloured alloy. Rolled roofing material is an economical choice for low-sloped residential roofs and outbuildings like sheds. It consists of long rolls of mineral-impregnated and asphalt-impregnated material topped with granules, and it’s often used on buildings where appearance isn’t important.
Tile roofing is a popular and attractive option that’s available in a wide range of colours and styles to complement any architecture. Clay and concrete tiles are molded into rolled or interlocking shapes and fired to hardness, making them a durable roofing material that can resist water infiltration and changes in temperature. They’re heavier than other roofing materials, however, so they require a strong roof structure. Slate is another high-end roofing material that’s available in a variety of shapes and sizes to complement any building style. It’s also highly resistant to fire and weather damage, but it’s expensive and difficult to install, so it’s usually reserved for prestigious homes or historic restoration projects.
Installation
The roof of a building provides protection from sun, rain, snow, and wind, as well as insulation and structural support. A properly installed and maintained roof can last a lifetime. During the roofing process, it is important to keep open communication with your contractor and make sure you understand all the costs involved.
During the inspection and estimate process, your project manager will discuss everything with you, answering any questions and addressing any concerns you may have. You will then receive an estimate for the work that needs to be done, and you can decide if this is within your budget. If you are re-roofing because of damage, your project manager will also review your insurance policy and help you through the claim process.
Once the contract has been agreed upon, your project manager will set up an appointment to begin the job. Prior to starting, the crew will prepare your property for roofing by setting up protective measures. Tarps will be attached to your roof line and wooden boards will cover anything around the base of your home to prevent debris from falling and damaging your plants or belongings. The crew will also cover your pool, move things from the deck or patio, and ensure vehicles stay on paved surfaces to avoid any damage.
After the underlayment has been installed, your roofing shingles will be installed in a pattern of rows that overlap one another by six inches and are nailed down with a nail gun. The nails will be close together near the edge of the roof and spread out more towards the middle to keep your roofing watertight. Roofing caulk will then be applied to any raw edges of your roof to make it weatherproof.