Are Vented Soffits Necessary? For some
Vented Soffit Panels Increase Air Circulation
Due to the small perforations, vented soffit panels increase the air circulation of the attic area. Solid soffit panels, on the contrary, effectively seal off the attic space from fresh air, causing the air inside to become trapped and grow stale.
Solid soffits can be used in accent areas or areas where a vented panel is not necessary. If you are going to use solid soffits underneath your overhangs, you have the opportunity to create a venting system that is tailored to provide proper air circulation throughout your attic.
You should install your soffit vents along your home's eaves. You can install them under the roof's eaves to help air circulate through your attic space.
Regular Soffits (Non-Vented)
These soffits do not have any openings or vents and therefore do not allow any airflow through the attic. Non-vented soffits are typically used for aesthetic purposes and are not recommended for homes as they can cause moisture buildup and mold growth.
Local Building Codes for Installing Soffit Vents
The soffit vents must be a minimum of 1 square foot for every 300 square feet of attic space. They can be either screened or unscreened, but they must be installed so that they allow for airflow.
Non-vented or continuous soffit works best when your roof has narrow eaves or if you need to ventilate a large amount of attic space.
Aluminum soffit is a solid upgrade from wood or vinyl because it is much more durable and weather-resistant. Aluminum won't rot or warp due to the elements, and it doesn't require all the maintenance of wood. Plus, it does not have the same flammability risk of wood or vinyl soffit.
Normal vented air likes to enter the attic lower down (near the bottom third of the attic ) and as it passes through, it will exit higher up near the top third of the attic space. If you have an attic with no soffit vents but 2 unobstructed gable vents, then you will probably be ok on ventilation.
A warm roof is designed to prevent any moisture from forming on cold surfaces in the roof construction. This means that warm roofs do not generally require ventilation, but there should be an Air & Vapour Control Layer (AVCL) or vapour barrier on the warm side of the insulation depending upon the detailing.
It is absolutely possible the ventilation system on your roof is excessive. Maybe your home is older and prior ventilation was installed by a homeowner, or incorrect vent sizes were used in an older roof layout. Too much ventilation can negatively influence the attic's and home's insulation as well.
The unintended consequence of your recently installed roof vents is that your house got colder. In the winter months, warm attic air is vented to the outside through the ridge vents and is replaced by colder outside air sucked in through the soffit vents. In essence there is a mini jet stream in the attic.
For any type of system (active, passive, or mechanical ventilation) a healthy venting ratio is one where the attic space requires a minimum of 50% intake ventilation and 50% exhaust, but ideally, a 60/40 is recommended, when possible.
For example, if your attic is 1,800 square feet, you'd simply divide 1,800 by 150 to determine that you need approximately 12 square feet of total ventilation for your attic. The vents themselves will need to be placed evenly around the bottom of your eaves.
The type of soffit you use depends on the type of roof you have. If your eaves are wide, then you can go with a vented soffit. However, if your eaves are narrow, then you should opt for a non-vented one. Regardless of which type of soffit you install, it will help ensure that you have proper ventilation in your attic.
Moderate eaves require soffit between 12 and 20 inches wide. Some homes with deep eaves may need soffit up to 30 inches wide or more. Soffit comes in various lengths to suit the project, from just a few inches all the way to several feet long.
Don't worry, replacing soffit and fascia boards is actually rather simple, and can be done by anyone with rudimentary DIY knowledge and experience.
For some overhang areas closed soffit works just fine, but for others—especially those that lead to your attic or are particularly large—vented soffit is recommended for proper ventilation. Be sure to check local codes to see what is allowed in your area as it may vary from build to build.
The price of soffit and fascia is usually determined by the type of the material, not the colour.
Without venting, moisture will build up on the material and cause mold growth and fungus to rot the wood. Meanwhile, the fascia board with the attached soffits is responsible for protecting the area under the rafters from any damage that may be caused by debris, insects and rodents.
Soffit vents are strategic air intake points installed beneath your roof's eaves, designed to: Prevent moisture buildup that can lead to mold and wood rot. Reduce heat accumulation that can damage roofing materials.
Soffit vents typically come at an average price of $325 per unit, with installation costs ranging between $300 and $350. Widely recognized as the primary venting solution, they are commonly paired with ridge vents for optimal ventilation.
The most common mistake homeowners make when installing insulation is to block the flow of air at the eaves. NEVER COVER ATTIC SOFFIT VENTS WITH INSULATION — use rafter vents and soffit vents to maintain airflow.