The 15 Parts of a Roof on a House

There’s a good chance you only think about your roof when something goes wrong. A leak or missing shingles may feel like a headache you don’t deserve.

But understanding the elements that go into constructing a roof could provide a greater appreciation for all this structure does for you and your home!

Parts of a Roof Exterior

The easiest parts of a roof to identify are those you can see!

While these exterior components are just the tip of the iceberg, they play important roles in your home's structure and overall curb appeal.

Covering: A covering is a finishing material that covers the roof’s interior structure. It is the part of the roof most readily visible from the outside.

In modern homes, shingles are the most common type of roof covering. However, metal sheets, solar panels, and stone tiles are a few popular alternatives.

Chimney: Many residential roofs feature a visible chimney. Chimneys extend vertically from the roof and ventilate potentially harmful or otherwise undesirable fumes from the home.

Chimneys are most commonly associated with wood-burning fireplaces. In homes without built-in fireplaces, the chimney may instead connect to ventilation for a stove or furnace.


Vent Pipes: In many ways, you can think of a vent pipe as a miniature chimney. But while chimneys are typically used to ventilate the air, most vent pipes are connected to the home’s plumbing system. Vent pipes provide airflow to the plumbing inside your home.

This air prevents a vacuum from forming within the pipes, a phenomenon that could slow or completely block the flow of wastewater out of your home.

Flashing: A solid material used to waterproof the roof covering. Flashing is commonly made of metal, plastic, and various composite materials. Roof flashing is often defined by its intended location.

All flashing — regardless of location — serves the same purpose. Flashing is frequently applied around chimneys, vent pipes, and points where different planes of a roof meet. What do all of these locations have in common?

They’re all prone to leaks!


Parts of an Interior Roof Structure

As with most aspects of home construction, the most important parts of a roof are not visible from the street.

The interior structure of a residential roof is what creates an attic space and protects the home’s interior from rain and other types of weather. Take away just one of these parts and your roof won’t work the way it should!

Underlayment: Directly underneath your roof shingles or tiles is something called an underlayment. This layer is essential to protecting the roof’s inner structure from rain, snow, and the elements in general.

Neglecting to install high-quality underlayment will leave your rafters, attic, and everything else inside your home vulnerable to moisture, mold, and mildew. Underlayment is typically made of one of three materials: felt, rubberized asphalt, or a synthetic compound.

Sheathing: Sheathing, or decking, is typically installed just below the roof covering and underlayment. This is a thick, solid layer that can support the weight of someone repairing or cleaning the roof.

Sheathing can be used with any style of roof covering. Most decking is made of plywood or comparable material.

Ridge Board: The ridge board is the upper beam running perpendicular to the roof’s rafters. It joins the rafters to each other and creates the peaked shape of most contemporary homes.

You may have heard of something called a ridge beam. While similar, ridge boards and ridge beams are not the same. The simplest way to describe the difference is that ridge beams are structural (load-bearing) while ridge boards are not.

Rafters: Rafters are one of the main structural elements found inside a roof. These structures connect to the ridge board (or beam) and slope down to the exterior walls on either side.


Collar Beam: A collar beam is another key structural element that spans between each pair of rafters inside a roof. In some homes, collar beams are left exposed to create a unique, rustic-style ceiling accent.

Parts of an Eave

An eave is the part of a roof that extends further than the building’s exterior walls.

Eaves serve many purposes, including evenly distributing the weight of the roof and redirecting rainwater away from the home’s foundation.

Eaves include several individual parts. Here’s what makes up a typical roof eave:

Soffit: A soffit is the underside of a roof eave. Soffits cover openings to the attic — keeping wildlife and the elements out — and provide a clean, finished look to your home’s exterior. Soffits may be vented or unvented.

Vented soffits allow fresh air to enter the attic space, preventing heat build-up inside. Meanwhile, unvented soffits are acceptable when the attic is properly insulated and sealed. You can identify which type of soffits your roof has by looking for holes in the material.

Fascia: Directly adjacent to the soffit is a surface called the fascia. Fascia boards run horizontally on the exterior edge of the eave — above the soffits. Fascia boards provide an aesthetically pleasing look and protect the internal rafters from the elements. In some cases, the fascia helps support the bottom row of shingles or tiles and the gutters.

Bargeboard: Bargeboards are diagonal strips of material that cover the last rafter on either end of the roof (also known as gables). Like soffits and fascia boards, bargeboards are both fashionable and functional. They offer a stylish finish to the front of the eave while protecting the rafter inside from moisture and other damage.

Drip Edge: The drip edge is a special (and incredibly important!) type of flashing installed along the bottom edge of a roof. It seals the edge of the underlayment and prevents rainwater from seeping underneath the roof covering.

A drip edge may be made of plastic or metal. It must be installed around the roof’s entire perimeter to prevent moisture damage inside the attic and beyond.

Gutters: A properly waterproofed roof ensures rainwater and snowmelt flows off the edge instead of entering the attic space. But where does that water go? Water allowed to flow straight off the eave will quickly cause damage to the home’s foundation below. Gutters direct this water away from the roof and foundation to a safer location.

Gutters should be installed wherever water flows off the roof. There’s no such thing as too many gutters!


Downspout: Of course, the gutter is just half of the solution. You’ll also need a downspout to redirect water down and away from your home. The downspout is the vertical portion of a gutter that reaches from the roof to the ground.

A downspout should always aim away from the home’s foundation — extenders can be used to ensure the water does not pool at the downspout’s base. You can also use a downspout to fill a rain barrel.

Final Thoughts

Your roof is responsible for keeping your family and belongings safe. It represents the security of homeownership, as well as the maintenance and costs that often come with it.

It’s true that few homeowners are climbing up on the roof to repair damaged flashing or replace missing shingles themselves. But ignorance shouldn’t be bliss when it comes to your home and how it works!

What roof repairs have you completed on your home? Are you planning to invest in an upgraded roof covering material — i.e., metal, solar panels, etc. — in the future? Let us know in the comments!