Complete Guide to Roof Construction

Roof Construction 101

In short, roof construction is the process of designing and building the structure that forms the top covering of a building. When constructed right, a roof protects the building from the elements like snow, wind, and rain, and upholds the structural integrity of the building. 

Multiple components make up the roof, including:

• Sheathing
• Underlayment
• Covering (shingles, tiles, panels, etc.)
• Flashing
• Ventilation
• Insulation

We’ll explore the components and materials of a roof in more detail in this guide. 

Roofs come in a variety of types and designs, such as flat roofs, gable roofs, and hip roofs. Determining the type of roof to build – as well as materials – depends on factors like climate, aesthetics, cost and structural requirements. 

When planning a roofing project, start by assessing the structural needs, selecting appropriate materials based on climate and budget, and creating a detailed timeline and budget. Don’t forget to account for permits, safety equipment, and waste disposal – these can be critical in ensuring your project meets safety standards and local regulations.

Post-construction cleanup is a crucial step in a roofing construction job. It includes removing debris, nails, and leftover materials, as well as ensuring the site is safe and free from hazards like loose shingles or sharp objects. This final step also involves inspecting the roof for quality assurance and addressing any minor repairs.

Key Components of a Roof

Roofs require various key components, each serving a purpose in upholding the structural integrity of a building, withstanding and protecting occupants from the elements, and enhancing aesthetic appeal. Here, we break down the most critical components of a roof:

Structure

The roof structure is the framework that supports the roof, typically made of wood, steel or concrete. Roof structure includes trusses, rafters and purlins. Together, these components ensure the roof can withstand loads like snow, wind, and the weight of roofing materials.

Trusses

Prefabricated triangular units that provide structural support. Trusses help to distribute weight evenly across the roof. 

Rafters

Sloped beams extending from the ridge to the edges of the roof. These support the roof deck and materials while creating the roof’s shape. 

Purlins

Horizontal beams supporting the roof deck or panels. Purlins prevent sagging and allow the roof to bear more weight. 

Roof sheathing

Also known as decking, roof sheathing is the flat layer, typically made of plywood or OSB (Oriented Strand Board), that attaches to the rafters or trusses and forms the base for the roofing material. Sheathing is important as it provides a flat, stable surface for roofing material to be applied and weight to be distributed evenly. It also offers the benefit of energy efficiency for the finished structure: it helps to prevent heat and cold air from seeping through the roof. 

While sheet sheathing is most common today – wide, flat sheets of plywood or OSB – plank sheathing is another method, made up of elongated and regular wooden boards. This method was most commonly used before the invention of plywood. 

Underlayment

Underlayment is a protective layer (usually felt or synthetic material) placed on top of the decking to add an extra barrier against moisture. It prevents water from penetrating the roof if the top layer of shingles or tiles is damaged. Without proper underlayment, the roof is more susceptible to water damage, mold, and rot, compromising the longevity and durability of the entire roof system. Underlayment is required by the International Building Code, so don’t skip this critical step!

Roof covering (shingles, tiles, panels)

The roof covering is the external layer that provides weather-proofing and aesthetic appeal, such as asphalt shingles, clay tiles, metal panels, or wood shakes. Asphalt shingles are the most common roof covering type, used in about 75% of roofing projects. Properly installed roof covering prevents moisture from seeping into the underlying structure – which could ultimately lead to rot, mold, and structural damage. The roof covering also contributes to the building’s energy efficiency by reflecting or absorbing heat. 

Flashing

Flashing is made up of metal strips installed around vulnerable areas like chimneys, vents, or roof valleys to prevent water infiltration. It’s vital to a roof structure because it seals and protects vulnerable areas where the roof surface intersects with vertical structures, like chimneys, vents, skylights, and walls. Flashing provides a watertight seal at critical points on the roof, making sure it remains durable and functional for years. 

Ventilation

Ventilation – a critical element to any roof structure – is defined as systems like ridge vents, soffit vents, or attic fans designed to ensure proper airflow and regulate temperature and moisture inside the attic. It’s crucial for maintaining the health and efficiency of a roof by allowing air to circulate through the attic or roof space. In a sense, proper ventilation allows the structure itself to be livable by regulating temperature and moisture levels, and preventing the buildup of heat in summer and condensation in winter.

Insulation

Insulation is the material installed beneath the roof to help with energy efficiency by reducing heat loss or gain through the roof. It’s essential for improving energy efficiency by minimizing heat transfer between the building’s interior and exterior. Insulation helps keep the structure warm in winter and cool in summer, making it more comfortable and livable. Another benefit of insulation is that it prevents condensation build-up, which can lead to moisture damage and mold over time. This ultimately protects the integrity of the structure, helping it last longer. 

FAQs of Roof Construction

Whether you are new to roofing or planning a new project, it’s difficult to know where to start. Explore commonly asked questions about roofing and roof construction. 

Is roofing considered construction?

Yes, roofing is considered construction. It involves building or repairing the roof, which is a fundamental part of a structure. Roofing includes steps like installing the roof framework, applying materials like shingles or tiles, and ensuring proper waterproofing and insulation. Since it requires skilled labor, materials, and adherence to safety and building codes, roofing falls under the broader category of construction work.

What are the most common kinds of roofing materials?

The most common types of roofing materials include:

Asphalt shingles: Widely used in residential roofing, asphalt shingles are affordable, durable, and come in a variety of styles and colors. They’re easy to install and provide decent weather resistance but have a shorter lifespan compared to other materials (typically 20-30 years).

Metal roofing: Metal roofs, made from materials like steel, aluminum, or copper, are highly durable, fire-resistant, and energy-efficient. They can last 40-70 years and are ideal for various climates, though they come at a higher upfront cost.

Clay and concrete tiles: These tiles are known for their longevity and resistance to harsh weather conditions, making them popular in hot or coastal climates. They can last 50-100 years, but they are heavy and require reinforced roof structures, adding to installation costs.

Wood shingles and shakes: Often made from cedar, redwood, or pine, wood shingles and shakes provide a natural look and good insulation. They’re durable but require regular maintenance and are more susceptible to fire unless treated.

Slate: Known for its elegance and extreme durability, slate is a natural stone material that can last 75-100 years or more. It’s resistant to fire and harsh weather but is heavy and expensive, requiring a strong roof structure for support.

Synthetic roofing materials: These include options like rubber, plastic, and polymer roofing, designed to mimic materials like slate or wood at a lower cost. They’re lightweight, durable, and require less maintenance, making them an attractive alternative in various climates.

Solar shingles: While not quite as common as some others on the list, solar shingles are rising in popularity due to their sustainability benefits. While they can generate enough energy to reduce or even eliminate your electricity bill, they are still very expensive and time-consuming to install. 

What is thermal shock in roofing?

Thermal shock in roofing occurs when sudden and extreme temperature changes cause rapid expansion and contraction of roofing materials, leading to stress and potential damage. For example, in hot climates, roofing materials may heat up significantly during the day and then cool rapidly at night. 

This frequent expansion and contraction cycle can weaken materials over time. This can result in cracking, warping, or even complete failure of certain components like shingles, metal panels, or membrane roofing. 

How can you prevent damage from thermal shock? Home and building owners should have their roof professionally assessed at least bi-annually to look for potential risk areas of thermal shock. Maintained roofs may last up to 25% longer than unmaintained ones. That’s an extra (approximately) 8 years!

What is TPO roofing?

Thermoplastic polyolefin – or TPO – is a single-ply white membrane used in both commercial and residential roofing. TPO is a white membrane, so it reflects heat instead of absorbing it. This type of roofing can help keep a room or living space cooler due to its heat reflecting nature. When installed and maintained properly, TPO roofing can last up to 25 years. 

And, good news! TPO roofing is generally considered relatively easy to install and maintain, especially for flat or low-slope roofs. It comes in large rolls, which can be rolled out across the roof deck and then either mechanically fastened, adhered, or heat-welded at the seams to create a seamless, watertight membrane. 

How long can slate roofing last?

Due to its nearly ancient history (slate was first used on a residential roof back in 1300s England), it’s no surprise it’s still commonly used as a roofing material today. It can last anywhere from 75 to 100 years (and sometimes even up to 150 years!) 

Slate is a natural stone material, making it highly resistant to extreme weather conditions, fire, and rot. Its longevity depends on the quality of the slate itself, the installation, and ongoing maintenance. So if you choose to install a slate roof, be sure to keep it assessed and maintained regularly.

Roofing Trash: How to Handle Roof Debris Removal

Now that you understand how a roof is constructed and the materials needed, it’s time to focus on the clean-up process. 

Handling roofing debris after a project ensures safety, site cleanliness, and environmental responsibility. And cleaning up roofing trash starts before you even begin the project. Before construction, plan how to manage debris by setting up designated disposal areas and renting a dumpster or using dump trailers to keep the worksite organized. 

For large roofing jobs, consider renting a roll-off dumpster and placing it close to the roof to speed up clean-up, so workers can toss debris directly off the roof rather than hauling it down manually. It’s also smart to use protective tarps or coverings to prevent nails, shingles, and other debris from scattering and damaging surrounding areas, such as landscaping or walkways.

Once the debris has been collected, sort and dispose of it according to local regulations. 

Many types of roofing materials, such as asphalt shingles, metal, and tiles, can be recycled. Contact local recycling centers to see if they accept specific roofing materials, as recycling can help reduce landfill waste and is often more cost-effective than dumping fees. For items that can’t be recycled, make sure they’re disposed of in accordance with environmental guidelines to prevent any hazardous material contamination. 

After major debris is removed, do a final walk-through with a magnetized tool to pick up stray nails and small metal pieces to ensure safety for homeowners and workers. Proper planning and disposal not only improve efficiency on-site but also protect the environment and community.

Site Services USA’s Roofing Debris Cleanup Services

Roofing projects can be complex. From planning and designing the roof to the actual build, you have a lot on your plate to make sure the job gets done right, safely and on time. Site Services USA is here to help.

Site Services USA is your partner in hassle-free roofing clean-up services. With years of experience in the construction industry and an expansive national network of vendors, your partners at Site Services USA work with you each step of the way to make sure your job is done right, whenever you need it and within budget. Here at Site Services USA, we don’t stop at delivering a dumpster rental for your site. We go the extra mile to ensure you have what you need, when you need it and within your budget. We offer guidance and round-the-clock support with a single point of contact who you can access any time via text or call. 

Ready to get started? Contact us today to get a quote.