How Far Apart Should Roof Vents Be Placed

This is ok provided the vents are near the ridge.

How far apart should roof vents be placed.

They should be divided equally between inlet and outlet vents and they can be used in any combination that will work with your roof s design. You need to have an equal number of vents located at the bottom of the attic or under the roof easement as you have at the top of the attic near a gable or ridge. Space the vents at the bottom and top of the attic equally according to house size. Ideally half the vents should be located in the soffit at the bottom of the roof and half in gable or ridge vents near the top to allow for natural circulation of air through the attic.

For the previous example you would need 20 soffit vents. Proper installation number and location of roof ventilation is needed to maximize the performance of a roof. Putting them at mid roof or lower is ineffective. Thus if your attic is 450 square feet you need roof vents equaling 3 square feet.

If your attic floor has a vapor barrier you will need one square foot of nfa per every 300 square feet of attic floor area half of that will be intake half for exhaust. This video has examples of both static and ridg. In this case they should be placed near the ridge so that the upper attic will be vented. If there is no vapor barrier double it to one square foot of nfa for every 150 square feet of attic floor space half for intake half for exhaust.

Otherwise the un vented roof slope simply won t be treated.