What is The Purpose of Soffit and Fascia?

In this article, you will learn:
1. The anatomy of a roof
2. The purpose and benefits of soffit
3. The purpose and benefits of fascia

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Maintaining your property can require a great deal of research, planning and organization.

While many Canadian homeowners are familiar with the upkeep of their windows, siding and doors – it is not uncommon for the lesser-known structures to go completely unnoticed.

Your roof, for example, can be made up of a variety of different parts that each play an essential role!

Although seemingly minor, soffit and fascia are actually two very important parts of a roof that not many people are as familiar with.

While every roofing part can contribute to the comfort, functionality and efficiency of your home – it is important to understand what each structure is responsible for!

At T. Simpson Roofing, we pride ourselves on client education and confident property maintenance.

The following sections will introduce the full anatomy of a residential roof, along with the purpose and benefits of soffit and fascia.


Your roof is made up from a variety of unique and important structures.

All of these structures must be functioning properly for the roof to remain secure, functional and efficient – so it’s important to know what you should be looking out for!

The following guide will help you identify and understand the purpose of each roofing component:

Attic – the space below the roof.

Chimney – a noncombustible structure that protrudes from the roofline to exhaust smoke and fumes. Typically made from brick or stone.

Chimney Cap – a metal or stone cap placed above a chimney flue to protect it from the elements.

Decking (or sheathing) – typically made from 1/2-inch plywood to reinforce the roofing structure. The decking also provides a nail bed for securing shingles.

Dormer – the structure around a vertically set window that projects from a sloping roof.

Downspouts – channels attached to the fascia that carry rainwater away from the roof and foundation.

Drip Edge/Gutters – installed along the outside of the roof to drain water from the roof and towards the downspouts.

Eaves – the lower edge of a roof that extends beyond the exterior walls.

Fascia – protective boards running along the edge of the roof or eaves.

Fasteners – attaches the roofing to the underlayment and deck. Can be made from roofing nails, tar, or even glue depending on the roofing material.

Flashing – thin waterproofing metal sheets that are installed around any vertical structures that intersect the roof (such as a chimney).

Gable – the triangular wall beneath any space where two roofing planes meet.

Hip – the space where two roof faces connect and project outward.

Ridge – the peak of two intersecting roofing planes.

Saddle – waterproof structure designed to divert rainwater away from projections (such as the higher side of a chimney).

Shingles – protective topical layer (most commonly asphalt) to protect the roofing structure. Also available in a variety of materials such as wood, metal, fibreglass and tile.

Soffit – the horizontal underside of a roof eave that extends past the exterior wall. Often fitted with vents to allow for air circulation within the attic and rafters.

Underlayment – protective fabric-like layer (typically made from asphalt-saturated felt) placed between the deck and the roofing material.

Valley – the angled intersection of two sloping roofs. Designed to help water drain towards the gutters.

Vent Pipe –protruding pipes that allow fresh air into the home’s plumbing system.

Vents – intake vents are situated below the eaves (or soffit) to help air circulation and moisture protection within the attic.


The term “soffit” originates from a combination of a French word meaning “formed as a ceiling”, and a Latin word for “to fix underneath”.

While not all properties may have soffits installed, the roofing structures that do are generally pretty easy to spot.

Visible from street level, the soffit is the horizontal underside of a roof eave that extends past the exterior wall. You can think of a soffit as your roofs “ceiling”.

While soffits are available in either solid or vented styles, vented soffits allow for air circulation within the attic and rafters.

What Purpose Does Soffit Serve?

With a clean, finished look to your otherwise-exposed eaves – soffit provide a variety of important benefits beyond their aesthetic appeal.

In fact, soffit protect your roof with the following key features:

– Protection from the elements
– Maintains air circulation within the attic and rafters
– Reduces risk of moisture buildup and condensation
– Decreases risk of ice dams, mold and decay
– Increases energy efficiency
– Improves energy expenses
– Prevents birds, pests, bugs and animals from entering the attic

By allowing your home to “breathe”, you have a much better chance of protecting and prolonging the quality of your roof for many years to come.

While a damp, moldy, and inefficient roof can cause deterioration and increase your energy expenses, it is very important to check your soffit every so often to ensure they are functioning as optimally as possible.


Fascia is an architectural term that originates from the Latin translation for “band, bandage or ribbon”.

Visible from outside the home, fascia is the exposed horizontal finishing board that connects to the ends of the roof rafters or trusses. It serves to support and carry your eavestrough and gutter systems.

Sitting just above the soffit, fascia is mounted to the space where your roof meets the outer walls of the home (also referred to as the roofline).

Available in a variety of different styles, colours and materials – fascia can do a great deal for your home’s overall aesthetic and curb appeal!

What Purpose Does Fascia Serve?

As one of the most visible trim elements of your home’s exterior, fascias provide a beautiful, finished aesthetic to your property.

However, the primary role of the fascia is to serve as a barrier between the outside elements and the inside of your roof!

While fascia block the risk of weather damage from entering your roof and home interior, it is very important that it remains properly sealed and caulked.

When properly maintained, fascia provide the following key benefits to your home:

– Protection from the elements
– Prevents water damage and moisture buildup under the roof boards
– Provides support to the bottom row of shingles
– Provides support to the eavestrough and gutter systems
– Protects the ends of the rafters
– Improves home aesthetic and curb appeal
– Prevents mold and decay

To ensure that your fascia is always functioning to the best of its ability, be sure to implement a bi-annual roof inspection to keep up on any necessary replacements and/or repairs.


When it comes to soffit vs. fascia – they always work hand-in-hand!

As these architectural elements are designed to protect your home from a variety of potential threats, soffits and fascia are both essential to the overall anatomy of your roofing system.

From weather protection and pest control to energy efficiency and curb appeal – these two factors contribute their important roles to the comfort, safety and functionality of your home.


While homeowners often invest in soffit or fascia that match the colour and style of their existing trim, there are a variety of materials to choose from!

When preparing for a roof repair or replacement, the most important thing is to select materials that will effectively protect your home.

At T. Simpson Roofing, we pride ourselves on the quality and practicality of our vinyl and aluminum soffit and fascia selections:


As vinyl is resistant to cracking, rotting and warping, choosing this material for your soffit and fascia will make them very low maintenance and easy-to-clean!

With a wide variety of colours and finishes, this cost-effective option does a great deal in providing style, protection and optimal energy-efficiency without breaking the bank.


Durability and ease of installation are the leading benefits of choosing aluminum for your soffit and fascia.

Available in regular or heavy gauge for high performance, there are a wide variety of colours and styles suited to just about every type of home.

Although more expensive than their vinyl alternative, aluminum soffit and fascia have a long, promising life span to keep your home protected for many years to come.

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If you are interested in learning more about your roof replacement options, our professionals at T. Simpson Roofing Ltd. offer the largest GAF Certified Roof Replacement Services in Canada!

Click here or call 1-800-925-3044 for more information.

T. Simpson

Originally founded by a 16-year-old Tony Simpson as a way of acquiring funds to help pay his way through university, T. Simpson Roofing, propelled by Tony’s strong work ethic and commitment to delivering quality work and unbeatable customer service, quickly grew into a thriving business.

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