Roof vent types
Exhaust vents compared.
Guide
Soffit Vent Types: Which Intake Vent Does Your Roof Need?
Soffit vents are the intake half of attic ventilation. Here are the main types, how much air each lets in and what they cost to add.
The types
Soffit vent types compared
Intake vents let cool air into the attic at the eaves. These are the main types, with net free area (NFA) from manufacturer specs.
| Type | Net free area | Best for |
|---|---|---|
| Continuous soffit vent | 9 sq in per linear foot | New soffits or retrofit along the whole eave |
| Perforated vinyl or aluminum soffit | Varies by panel; the retrofit perforated strip we checked lists 9 sq in per linear foot | Homes getting new soffit panels |
| Individual undereave vent | 28 sq in per vent | Wood soffits; adding intake in spots |
| Vented drip edge or Edge Vent | 9 sq in per linear foot | Homes with little or no overhang |
NFA figures from Air Vent’s published intake vent specs. Panels vary by maker, so check the spec for the product you use.
Why it matters
Intake is half the system
Exhaust vents at the ridge only work if cool air can get in low. Too little intake and the attic pulls air from the house instead, or the exhaust stalls. Most ventilation is designed as a balance of intake and exhaust.
Run the numbers for your attic in our roof ventilation calculator, and see roof vent types and ridge vent vs box vent for exhaust options.
Cost
What soffit vents cost
| Job | Typical cost |
|---|---|
| Eaves ventilation strips | $2.50 to $4.00 per linear foot installed |
| Soffit replacement (1 to 2 ft wide) | $4 to $22 per linear foot |
| Roof vent installation | $200 to $700 |
Source: HomeGuide’s soffit and fascia repair cost guide and HomeGuide’s roof replacement cost guide. Blocked soffit vents, often from attic insulation, are a common find; baffles keep the airway open.
Questions
Soffit vent questions
What is the best type of soffit vent?
A continuous soffit vent gives even intake along the whole eave. Air Vent lists 9 sq in of net free area per linear foot.
How many soffit vents do I need?
Enough intake area to balance your exhaust. Work out your attic’s total from its floor area in our roof ventilation calculator.
What if my house has no soffit overhang?
Use a vented drip edge or a roof-edge intake vent. Air Vent lists 9 sq in per linear foot for both.
How much do soffit vents cost to install?
Eaves ventilation strips cost $2.50 to $4.00 per linear foot installed, per HomeGuide.
Can insulation block soffit vents?
Yes. Blown insulation often covers them. Rafter baffles keep a clear channel from the soffit to the attic.
Keep reading
Related guides and calculators
Roof ventilation calculator
Intake and exhaust you need.
Soffit and fascia
Our soffit and fascia service.
Fascia board replacement cost
If the eaves need work.
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