What Is Soffit and Why Is It Important?

If you’ve been considering upgrading the exterior of your home, you’ve likely come across the word “soffit.” Doing so might lead you to ask, What is the soffit on a house, anyway? You wouldn’t be alone. Though many homeowners are familiar with the terms that make up part of their home’s roofing system, many cannot point soffits out or even know their purpose. 

A soffit is an exposed underside of a roof overhang or eave that covers the gap between the edge of the roof and the wall. Roofers usually install a soffit at a 90-degree angle to an exterior wall parallel to the ground. But installation varies by roof type.

Soffit vents attach to the eaves and circulate air in your attic, preventing moisture problems. Soffits usually range from 12” to 24” wide to allow space for the soffit vents.

Keeping air moving inside your attic creates an effect called convection. Soffit vents help exhaust moist air from the attic to the outdoors. Cross ventilation is made possible with the soffit vents and aids in convection, which assists in dissipating heat and prevents premature aging of your roof. 

Without the vents, heat could escape from your home, resulting in increased moisture in the attic, mold formation, and an increased potential for ice dams on your roof in the winter.

We’ll discuss in greater detail what benefits soffits provide, why they are required, and how they are installed.

What Is theSoffit on a House?

A soffit is the material that covers the underside of your roof’s overhang. They fall between the roof’s edge and the exterior wall of the house.

Soffits are typically attached to the rake or fascia board on one side and to the exterior wall on the other side. 

Most modern building codes have specific requirements regarding soffits in residential construction, as they perform several duties and provide multiple advantages. 

Soffits are installed to protect the attic from vermin and insects, provide cross ventilation, and prevent blowing rain from damaging the rafters.

Soffits usually contain vents that work with your other roof vents to keep your attic dry. Hip and valley roof types tend to use soffit vents in combination with ridge vents located at the very top of the roof. 

In contrast, homes with a gabled roof will depend on gable vents for this task, but they will, too, work together with the soffit vents to circulate air. Stale, stagnant air in your attic will condense into liquid water, possibly leading to mold growth.

Today, most homeowners opt for vinyl soffits because they are inexpensive, easy to use, and durable. To a lesser degree, wood soffits are used, although they’re more expensive than vinyl. Metal and fiber cement soffits are other possible options, as these are very durable materials. However, vinyl soffits require the least maintenance.

Why Do You Need a Soffit?

What a soffit can do for your home goes beyond any aesthetic benefits it can offer. A soffit protects your roof and attic from damage by water, insects, animals, and airborne debris. 

Without soffits, your home’s attic would struggle to stay dry in some climates, as the moisture would not be drawn as easily outdoors. 

Soffits also help conserve energy by removing heated air in your attic that can enter your home (via conduction) if the insulation is inadequate.

Here are some of the benefits of soffits:

• Seals the underside of your roof’s edge
• Holds the soffit vents that aid in cross ventilation
• Is removable to allow outside access to the attic
• Prevents moisture that attracts damaging insects
• Deters birds that would otherwise be attracted to insects, thus warding off further damage 
• Keeps the rake and fascia boards straight adds symmetry
• Provides a finished look that enhances the curb appeal and increases the value

Soffit also beautifies the look of your home by providing a sleek, finished look that enhances curb appeal. There are even multiple color choices available that you can choose from to complement your home’s exterior.

How to Choose and Maintain Soffit

You’ll want to choose soffits that are sized and designed for your home. Your budget, style, and needs will often determine your choices. It’s also wise to consider the soffits maintenance requirements and accessibility, as some are more challenging to access for repairs and upkeep. 

Generally, soffit installation is not a first-time DIY project, as the job requires ladders, walk boards, or scaffolding. Hiring a professional to install your soffits is money well spent, as they will have the tools on hand that you would otherwise have to rent.

The following are a few features of the most common soffit designs and the benefits they offer.

Vinyl Soffit

Vinyl soffit is inexpensive to purchase and install while remaining essentially maintenance-free. Roofing contractors install vinyl soffits as part of a system, not individual components. Vinyl soffits may include other vinyl parts, like F channel, J channel, and an aluminum component called trim coil.

Wood Soffit

Wood soffits are composed of ¼” thick luan plywood and attached to the exterior wall along one edge, and the fascia or rake board is installed along the other. Usually, the installer will route a groove into the back of the rake or fascia board, which fits the plywood soffit.

Fiber Cement Soffit 

Fiber cement soffit is cut and installed similarly to wooden soffits. However, cutting fiber cement boards requires personal protective equipment, so caution is advised. A fiber cement soffit is also about ¼” thick and can be attached using corrosion-resistant fasteners. 

The real benefit of fiber cement soffit is that the material can handle very high temperatures without igniting. Wood and vinyl will combust in a fire, but fiber cement soffits will not fuel a flame. 

Fiber cement soffits do, however, require precise installation procedures, fasteners, and regular sealing, which can be a hassle on a multi-story home.

Metal Soffit

The real benefits of metal soffits are their resistance to heat and the fact that they’re lightweight. Metal soffits are among the easiest to install, as many systems interlock, reducing the number of fasteners required. However, metal soffit is often the most expensive option, and the material will dent.

Pro Tips For Cleaning and Repairing Your Soffits

Ideally, the best option is to hire an experienced professional to clean your soffits, as they can be difficult to access and very high. If you feel it is safe for you to clean your home’s soffits, here are a few things to keep in mind:

Cleaning Your Soffits

• Sometimes all it takes is a soft brush with bristles. A mild solution with regular household detergent, clear water, and a garden hose will do the trick without damaging the soffits.

• Some soffit materials, such as a pressure washer, need a heavier application, but be prepared to get wet.
• Brushes and brooms are effective at removing dirt and grime, but working over your head for hours can be exhausting.
• Hiring a professional is often the best solution, and they can inspect your soffits while they are there.

Repairing Your Soffits

Repairing your soffits is not recommended for new DIYers, as the job is physically taxing and fairly complex. However, vinyl, metal, and wood are the easiest to repair if you need to make a spot repair due to damage.  

It’s a good idea to leave fiber cement repairs to professionals as they have the appropriate safety equipment, like a respirator, eye protection, and gloves. Fiber cement also requires special cutting/shearing tools to reduce or eliminate the dust created by sawing, as the dust is a lung irritant.

Key Takeaway: Soffits are More Important Than You Might Think 

We’ve shown you what a soffit is and why it’s important to your home’s and your family’s health. 

The exposed underside of your roof’s overhang between the exterior wall and the roof’s edge serves an important purpose.

Soffits protect your home and roof from water damage and ensure adequate ventilation in your attic. 

Maintaining your home’s soffits and keeping them in good condition is vital to prevent damage. Keeping soffit vents clear helps your roof last as long as possible while reducing the moisture in your home.

If you’d like an evaluation of your current soffits to learn if they’re adequately protecting your home, contact our soffit and roof experts. 

We’re happy to meet with you to analyze your roofing system or provide an estimate on soffit replacements. We have local contractors located in most states across the U.S.