18 Parts Of A Roof And Their Functions

November 18, 2021

The 18 Main Parts Of A Roof System And What They Do

Learn To Speak “Roof” With Authority

Most homeowners in the Houston area are just happy to know their roof isn’t leaking and never give it another thought. But when trouble comes knocking and you need your roof repaired, it’s helpful to speak your roofer’s language, if only to understand what they are telling you.

A key fact to understand is that your roof is more than just the shingles on top. Your roof is an intricate system designed to withstand high winds, drenching rains, and heavy snow (not that snow is a real concern around here). Each part of your roof is the result of centuries of problem-solving as we learned how to make roofs more reliable and longer-lasting than those from the last generation.

Below is a list of the most important parts and features of your roof and what they do.

Visible Features Of Your Roof

Your roof’s most visible features almost always have a purpose to their shape. Some shapes are unavoidable, while others are the result of experience and careful engineering. They each have a specific purpose, and some shapes give them the best chance at doing their job for years to come.

  1. Ridge – The ridge is formed where the upper edges of roof planes meet. While they look enclosed, modern ridges are used as a source for additional ventilation and are covered with specially designed shingles that keep the space free of critters and rain/snow.
  2. Valley – Valleys are formed where the lower edges of roof planes meet. The valley functions as a gutter, collecting rainwater and directing it to the roof’s edge’s gutters.
  3. Vents – Venting is an important factor in your roof’s design, and modern roofs have many vents along the surface. Proper roof venting keeps the air moving underneath your roof and keeps the internal roof components dry while preventing mold formation or other sources of trouble.
  4. Gutters – Rain gutters collect the water that sheets off the roof and releases it through a downspout to flow away from your home’s foundation. Some roofs will have a large enough overhang that gutters aren’t necessary, but you’ll see gutters on most residential roofs.
  5. Abutment – An abutment is an area where your roof comes against any vertical surface, such as a wall or the side of your chimney. Abutments create a seam on your roof’s surface and must be protected to prevent leaks.
  6. Flashing – Flashing is placed over an abutment to keep water from infiltrating into the seam. It is usually made of galvanized metal custom-formed at the worksite for the tightest fit possible. Roof flashing is also used anywhere there could be a problem, such as the valleys in your roof.Once the desired shape is achieved, the flashing is made watertight with roofing specific sealant. The most easily viewed flashing is around the base of your chimney.
  7. Eave – The eave is the area of your roof that hangs past an exterior wall. Eaves can be left open or finished with material that leads back to the wall for a cleaner look and more secure structure.
  8. Soffit – The soffit is the horizontal structure covering the space between the eave and the exterior wall. Your soffit can be plain or fancy, depending on your taste and budget, but they must include a form of venting. Often the venting is just a pattern of tiny holes in the material; other times, it is achieved with a series of louvers.
  9. Fascia – The fascia is any vertical facing along the edge of the roof. Fascia can be just a few inches to over ten inches wide and can be plain or decorative, depending on your goals. Its main purpose is to present a clean line for the roof edge and offer a surface for attaching the gutter. 
  10. Gable – The gable is the area of your exterior wall that rises to the point of your roof’s ridge. Homes with this feature are said to have a gable roof. Gable roofs are the most common roofing system in the nation and allow for the most significant amount of usable space underneath the roof.
  11. Hip – The hip of your roof is any spot where two roof planes meet without extending to the ridge of your roof. The part of your roof with this feature is said to be hipped, and a roof that only has this shape is called a hip roof. Hip roofs are popular in areas that encounter extreme wind conditions due to their ability to shrug off heavy winds.
  12. Dormer – Dormers are cutouts in your roofline where windows are extended out to provide natural light and additional space for the interior. Most dormers will have a small gable roof covering them, even if you have a hip roof over the rest of your home.
  13. Rake – Rake is more a term than a feature. The rake of your roof is any steeply sloped plane on its surface.
  14. Drip Edge – The drip edge is installed along the edge of your roof and exists to prevent water from coming back up under the surface of your roof.

Roof Construction Elements



The most important parts of your roof are hidden from your eyes, except for the covering. We continue the list with these final entries.

  1. Truss/Rafters – The triangular structures connecting your roof to the rest of your home are called trusses but are often called rafters. Specifically, the rafters are the boards running at an angle from the ridge board to the home, while a truss is the complete supportive structure. 
  2. Sheathing – the plywood that covers the trusses is called the sheathing layer. It has two jobs: tying the trusses together and supporting the roof covering. Simple roofs will sometimes use metal sheathing and just leave it at that. You’ll find these simple metal roofs on barns, sheds, and older garages.
  3. Underlayment – Underlayment sits directly against the sheathing and is designed to prevent moisture from reaching the more vulnerable parts of your roofing system. The underlayment can have multiple layers, with water barriers and roofing felt being the most commonly used underlayment system in modern roofing.
  4. Shingles/Covering Materials – Asphalt shingles are by far the most common finishing surface for residential roofs and have been for decades. They are relatively inexpensive while durable enough to last from 15 to 30 years. Metal roofing has become popular over the last decade and comes in standing seam systems and tiled systems that can mimic almost any other type of roofing material. They can last anywhere from 30 to 50 years with little maintenance. With proper maintenance, more expensive roof coverings, such as slate tiles and wooden shake, can create an amazing look and last for over 100 years.

Caring For Your Roof

Every roof is different, and there are as many maintenance recommendations as there are roofing manufacturers. The one consistent thing is that each manufacturer knows best how to maintain their product, so following their guidelines is always your best bet for keeping your roof in good shape for as long as possible.

If you have any concerns about your roof, call us at Houston Roofing & Construction for a free inspection. Our experts will tell you everything you need to know about your roof and recommend any necessary actions.

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