What Is a Soffit?
You can define a soffit as a panel that encloses the underside of the roof overhang, extending from the exterior wall to the edge of the roof. You can also call the collection of individual soffit panels that run around the perimeter the soffit on a house . Soffits give your home a finished look, but the benefits go beyond appearance:
- Soffits protect your rafters, roof deck and attic from weather and pests.
- Vented soffits pulling in cooler air into an attic while warm, moist air exits the space.
Keep in mind, soffit vents form only the intake of your attic and roof ventilation system. You need an exhaust component as well, such as a ridge vent. Soffits aren’t suitable for all ventilation systems.
While you can find individual, circular soffits, wall soffits and soffits that allow exhaust from a bathroom fan or kitchen exhaust hood, for this guide we primarily cover soffit panels for a roof installation.
Soffits and Fascia: You may wonder about the difference between soffits and facia. Soffits enclose the underside of the roof overhang and fascia cover the roof edge. Both soffits and facia protect your roof while improving its appearance.
Soffit Vent Types
Your building codes might specify ventilation requirements and soffit types for your home. Talk to a professional builder or roofer to find the right ventilation for your attic and roof before you decide on vented soffits, but if you’re considering this type of ventilation, in general you need to:
- Determine the amount of ventilation you need.
- Choose fully vented or center-vented and continuous or individual soffit vents based on the amount of airflow necessary.
- Choose a material based on factors like appearance, durability and maintenance needs.
Estimating Soffit Ventilation Needs
The number of soffit vents you need depends on factors such as the type of vent, the design of your home and roof and local codes. However, here are tips for planning:
- If you’re replacing soffit vents, you might simply need to replace the existing soffit panels with new panels of the same size and with the same ventilation properties.
- If you’re planning soffit installation for a new home, you can create a rough estimate of the amount of vent space you need based on the square footage of your attic. As a general rule, plan for at least a square foot of ventilation for every 150 square feet of attic space.
- The Net Free Area (NFA) specification of a soffit vent tells you how much ventilation a single panel creates.
These tips give you broad estimates to use as a starting point. Keep in mind soffits are only part of your whole ventilation system. Other attic and roof ventilation is a factor as well.
Types of Soffits
Soffit panels are usually fully vented, center vented or solid. The type you need depends on building codes and the amount of ventilation you need the soffits to provide.
- Fully vented soffits have perforations or openings across the entire surface. They allow maximum ventilation and are best if you live in an area where high heat and moisture levels are common.
- Center-vented soffits have a smaller perforated area and draw in less air. This type of soffit vent might be appropriate for areas with mild temperatures and low humidity levels.
- Solid soffits have no perforations. The give the underside of the eaves a clean look but are only appropriate if the roof has a separate ventilation system.
You might also see references to continuous and individual soffit vents.
- Continuous soffit vents run the length of the roof eaves and provide more ventilation.
- Individual soffit vents might be appropriate for areas where ventilation needs are lower.
Soffit Vent Materials
Unless your local codes specify a soffit material, you can choose the material based on the look, durability and maintenance needs:
Vinyl Soffits
- Vinyl soffits are resistant to moisture and corrosion.
- Vinyl soffits don’t require paint or stain.
- Vinyl soffits offer several color options.
- Sunlight can degrade and discolor vinyl soffits over time if they don’t have UV (ultraviolet) protection.
Aluminum Soffits
- Aluminum soffits are durable, resisting crackling and UV damage.
- Aluminum soffits have moisture and corrosion resistance that makes them good options for coastal areas.
- Aluminum soffits are available in several colors.
- Aluminum soffits tend to be more expensive than other types.
Steel Soffits
- Steel soffits are strong and highly durable.
- A galvanized finish on steel soffits helps reduce the risk of rust and corrosion.
- Steel soffits are heavier than other materials, making installation a bit more difficult.
Plastic/Resin Soffits
- Plastic/Resin soffit vents resist moisture damage and don’t corrode.
- Plastic/resin soffit vents often feature UV protection.
Wood Soffits
- Wood soffits can be more visually appealing than other types.
- You can paint or stain wood soffits to match or complement your home exterior.
- Wood soffits are more vulnerable to damage from the elements and insects.
- Wood soffits require more maintenance than other types.
Fiber Cement Soffits
- Fiber cement soffits are very strong and durable.
- You can find fiber cement soffits in colors to coordinate with your home exterior
- Fiber cement soffits have a longer potential lifespan than other options.
- Fiber cement soffits are heavier than other options, making installation a bit more difficult.
Maintaining and Repairing Soffits
Keeping your soffits in good shape lets them provide the proper airflow to ventilate your attic space. Well-maintained soffits also keep pests away from your attic and roof structure:
- Restore airflow by removing any spider webs and having a professional remove any nests of stinging insects.
- Remove and replace warped, damaged or corroded soffits with new panels that have the same ventilation properties.
- If any panels are loose, secure them in place with the designated fasteners to close gaps.
- Clean away dirt, mildew and moss with a soft brush and mild detergent to improve the look of your home.
- Repaint or restain and reseal wood soffits to protect them from moisture and UV light.
- Reseal joints between the panels, as necessary.
While you can inspect the panels from the ground, you’ll need to work from a ladder for any soffit repairs. Follow all safety instructions when using a ladder and have a helper hold the ladder in place.
Get Help With Home Ventilation at Lowe’s
As part of an attic and roof ventilation system, soffit vents improve airflow and reduce moisture in an attic space. But soffits are just part of a complete ventilation system. Shop Lowes.com for other home ventilation products that protect your home and improve comfort. Stop by your local Lowe’s and talk to a Red Vest associate. They’ll help you find the right ventilation products for your home.