Roof Anatomy: Important Parts of a Roof

roof framing construction

Have you ever looked at your roof and wondered how it is actually constructed? It might look like a simple covering to most people, but there are different parts that make up the roof. Mostly, only professional contractors know the parts of a roof and how it’s assembled for the final product. But, after reading this article, you’ll have as much important information as a professional contractor.

Understanding the parts of a roof, how it works, and what they are composed of will always come in handy for future home improvements. Your home’s roof is made up of more than asphalt shingles. There’s a series of components that protect your home from the rain, wind, and snow. It is critical to understand the parts of a roof in order to explain a problem to a roofing professional and understand what he or she is talking about when he or she is doing repairs.

There are quite a few parts of a roof on a home including different layers and features, which we will be focusing on in this article.

Roof Parts and Their Functions

Every homeowner should understand the parts of a roof. Here is a list of layers, features, and terminology:

  • Deck – Decking is the most important part of a roof, which acts as a base. Every roof has a deck as the first layer which is laid and nailed in an orderly manner to be able to present a stable and attractive exterior. Some of the topmost used material for deck framing systems includes plywood, polystyrene, concrete, and metal.
  • Rafters – Rafters are part of the roof decking that gives the roof a stable structure entirely. It is basically a diagonal-shaped structure frame of a roof included in the truss. It’s one of the most important parts of a roof because it supports the roof decking system. Rafters are generally made of wood and metals.
  • Sheathing – Sheathing is a board or sheet fastened to rafters. The purpose of sheathing is to provide support to the shingles to be firmly nailed and to provide broader roof support by evenly distributing any extra loads carried by the roof. The sheathing is also a part of a roof where a solid decking will be nailed. If this section is not installed firmly and regularly, then your roofing system will quickly fall.
  • Fascia – Fascia is also known as the roofline because it acts as a meeting point between the outer wall and the roof. Similar to the sheathing, the fascia is also nailed to the rafter to work as a support for the gutters. Fascia is one such part of the roof that can be seen on the exterior of the house. The most commonly used material for fascia includes wood, vinyl, and aluminum.
  • Eaves – Eaves are located at the lowest point of the roof. To make it simple, it’s basically the edge of the roofing system and a spot where rain drips off the roof, making it an ideal spot for gutters. Technically, it functions to clear the wall with water trickling down the surface.
  • Ridge – Ridges, or keystones, are important parts of a roof that connects the highest point of intersected roof sides. Ridges are mainly used in gambrel, gable, mansard, and pitched roof types. The ridge board is the key to all truss sections. It is a horizontal timber or metal board that supports the overall decking system. It is also a section where two ends of the rafters meet each other. Without this ridge board, none of the parts of a roof would form a solid frame for your house protection.
  • Roof Covering/Shingles – These are the topmost outer layer of a roof. Shingles are the part of a roof that provides the roof extra layer of protection and adds an element of style and design to the home. Some of the most used shingles are asphalt, metal, slate, tile, stones, wood, and plastic. Depending on the needs of the house, it comes in different sizes, shapes, and colors.
  • Underlayment – Underlayment are thin strips of black colored paper used for protecting the deck against air or water intrusion and other outdoor elements. Some important parts of a roof that need underlayment include rafters and valleys. There are two types of underlayment:
    • Felt underlayment – Felt underlayment is considered to be a part of greater underlayment and is usually found beneath the shingles. Installing a felt underlayment will save your home from broken shingles.
    • Synthetic underlayment – Synthetic underlayment are typically made of felt and rubber strips that are installed directly in the deck.
  • Valley – Valley is a meeting point of two pitched/sloped roofs, forming an angle of 90 degrees. The purpose of the roof valley is to collect the water that will fall off the roof. In addition to that, it supports the valley rafter which in turn supports an internal roof gutter. Usually, it is made of metal. It is also the spot where the fallen leaves or other debris from outside your home gather. If you don’t clean this part of your roof regularly, it could cause some serious damage.
  • Chimney – The chimney is another vertical element that connects through the roof. It acts as ventilation for exhaust smoke, combustion gasses coming from the stove, boiler, or fireplace.
  • Flashing – Flashing is a metal material installed at the joint opening including chimneys, dormer, windows, and skylights. The only objective of flashing is to help prevent water intrusion.
    • Vent Pipe Flashing – A vent pipe is a plumbing system that sticks up to the roof. It’s important to have a vent pipe flashing because it prevents the water from entering the building, reducing the heat, and also regulating air circulation so that your home is free from moisture.
    • Chimney Flashing – Chimney flashing can be found at the meeting point of a roof and the chimney. It helps prevent moisture from entering the house.
    • Valley Flashing – Valley flashings are generally found at the valley intersection where two roofs meet. Flashing helps block water from entering and absorbing into your building.
    • Skylight Flashing – Flashing is also important in the skylight because it’s that part of a roof that is more prone to leakage. Skylight flashing is applied in between the skylight glass and frame.
    • Dormer Flashing – It is essentially used to add more protection to the roof against water damage. Dormer flashing is installed under the sides and on top of the roof’s steel or at the dormer’s bottom or end wall.
  • Battens – Battens, also known as roofing laths, are wooden or metal strips that hold the shingles and tile in place. It helps protect the shingles from damage.
  • Abutment – And abutment is empty space in the roof where the roof’s slope intersects to vertical areas such as chimneys and walls.
  • Ceiling Joists – Ceiling joists are beams made of wood that connect the diagonal rafter. It provides extra support for soffits, eaves, and balconies.
  • Collar Beam – Collar beam is mostly used for residential roofing. It’s a beam made of either wood or metal that connects two rafters intersecting at the ridge. The collar beam provides more stability to the structure and is used to frame the ceiling structure.
  • Soffits – Soffits are the finishing material made of wood or fiber cement that covers the roof overhang’s underside to conceal the ceiling joists and rafters. It is basically located between the wall and eaves and will be visible when you straighten a roof up. Its basic function is to protect the rafters from natural elements such as moisture and molds. Which helps preserve the longevity of the materials.
  • Gutters – A gutter is a channel made of a long pipe that extends along the roofline. Gutter helps direct the water to the downspout without damaging the roof and the wall of a house.
  • Downspout – A downspout is a pipe that is attached at the end of a gutter. Just like gutters, they are meant to channel water to a designated outflow point. Downspouts are usually made of PVC, galvanized steel, plastic, and other water-resistant materials.
  • Insulation – Insulation should be an important part of a roof if you want to save thousands on energy bills. Insulations are basically a thick and spongy cotton-like material that keeps heat and cold out of the home.
  • Skylight – Skylights are often not considered as parts of a roof but it is considered to be aesthetic and functional. Think of a skylight as a window on a roof that provides additional lighting, sky view, ventilation, and a place of escape in times of emergencies.
  • Roof Ventilation – Ventilators are mainly located under the eaves of the roof. It helps reduce the amount of humidity that builds up in the attic and helps draw in cooler dry air. It is crucial to have a constant stream of air flowing from one side of the attic to the other.

Final Thoughts

Now that we’ve covered all the different parts, you should be familiar with the basic anatomy of a roof. More importantly, you’re equipped to have an informed conversation with your contractor when the time comes for you to get a new roof. Understanding more about your roof is vital for anyone who plans to install a new roof, needs roof repair, or plans on doing roof works.

After breaking down the parts of a roof, starting from structural elements, layering sections, to the exterior components, you can finally find out that all of them support each other. Understanding the parts of a roof also helps you immediately resolve any problem yourself without spending more on professional hiring. Lastly, before you make any decision about your roof, consider the life-cycle, cost, maintenance, environmental and other factors very carefully.

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