If you plan to install insulation on your attic floor, then most building codes require that the attic be vented. If a roof has only soffit vents and no ridge vents, most codes require 1 square foot of net free ventilation area for every 150 square feet of attic floor area.
Also asked, are soffit vents necessary?
Static, roof-line, vents are effective for ventilation but generally aren’t recommended due to issues with leaks. Soffit vents may leave air trapped at the top of your attic. Most effective ventilation uses a ridge-and-soffit continuous ventilation system, but even these designs can vary from roof to roof.
Beside above, how do you know if you have soffit vents? There’s a good chance your home does have soffit installed. The easiest way to tell is to walk around the home and look up at the roof. If you can see the underside of the eaves, but you can‘t see the rafters, your home has soffit.
Similarly, you may ask, how many vents in soffit are needed?
Calculating the Number of Soffit Vents You Need Divide this number by 300 to get the venting area. For example, a 1200 square foot attic space would require 4 square feet of venting.
Where should soffit vents be placed?
Soffit vents are installed under the overhang in the eaves (known as the soffit) to allow cool, outside air in the attic to reduce the temperature.