Your Home’s Soffit: What It Is & Why It Matters

Derek Perzylo

October 11, 2016

Soffit plays an important role in how your home’s exterior envelope protects the attic and structure from moisture, debris, and pests. It is relatively “hidden”, residing under the roof overhang. Most of the time you have no reason to think about your home’s soffit- it just does its job.

In this post I thought I’d go over a bit about what soffit is, what it does, and why it’s important to ensure that the soffit on your home is in good repair.


Walk outside your home- use any door that has a roof overhang above it. Outside? Look up. The material that stretches from the wall to the edge of the underside of the overhang- that’s sofft.

Diagram Showing Fascia & SoffitSoffit covers the underside of the rafters, improving the aesthetic value of the home while also preventing moisture and pests from getting into the roof and attic.

We install perforated aluminum soffit, though other materials – including wood – may also have been used for your soffit installation. We prefer aluminum due to its durability, aesthetic properties, and ease of use.

Soffit can be basic, or it can be installed with light fixtures and other hardware pre-installed. Installing pot-lights into your soffit is a great way to improve exterior lighting while retaining a sleek, contemporary look.

Perforated soffit – such as the soffit pictured here – also improves ventilation throughout your home. Ventilated soffit allows air to flow into your attic, allowing the attic to cycle air and moisture (reducing moisture build-up).

Why We Install Aluminum Soffit

Soffit comes in a variety of forms. The most common materials soffit is made from are aluminum, steel, plastic, and wood. Compared to wood, steel soffits offer superior moisture protection and longevity.

Compared to steel, plastic soffits offer improved durability and corrosion resistance. In Alberta, with our crazy rain and hail storms, corrosion resistance matters.

Compared to plastic, aluminum soffits offer further improved durability. Where plastic gets brittle over time (especially so thanks to Calgary’s below-zero temperatures), aluminum soffit continues to retain its mechanical and aesthetic properties. In other words, unless it is physically damaged, aluminum soffit is as “set and forget” as it gets!


Attic Ventilation

Most Calgarians have likely never stepped foot in their attic, and thus are unaware of the importance of proper attic ventilation.

In the summer, a properly vented attic will help keep your home cooler. It does this by allowing hot air to leave the attic, drawing in cooler air from within the home and the surrounding external air. In the winter, a well-ventilated attic will ensure the roof stays cold, preventing snow from prematurely melting on the roof and creating moisture problems (resulting from moisture running through the eaves and freezing in the dead of winter).

Ventilated soffits facilitate the uptake of air and promotes proper attic ventilation.

Moisture Resistance

Without soffits there would simply be open space between your rafters and the outside world. Obviously, this creates easy opportunity for moisture to find its way into your attic. Moisture building up in the attic is a real problem. It can seep into the insulation, walls, and ceiling; as anyone who has ever had water problems will tell you, once it’s in the home it can be difficult to determine where it came from and how to fix it. Soffits are a physical barrier between the rafters and the outside world. The other aspect of moisture control your soffits contribute to its humidity control. Calgary doesn’t have a humid climate, so this is not something that is on most people’s mind, but it’s an important function just the same. By facilitating proper ventilation, soffits help ensure that the attic does not become stagnant and humid. Again, this helps prevent moisture problems from arising.

Pest Control

Soffit is usually installed in conjunction with another material, such as eavestrough, fascia, or siding. We also commonly install it after installing a new roof. It is rare that we install soffit on its own with no other component.

Do You Need New Soffit?

If your soffit is in need of repair or replacement, please contact us. With over 30 years experience, we’d love to come take care of your soffit needs!

Recent Posts

Related Posts

Oak Wood Texture