Can you have too much roof ventilation?

It's possible to have too much exhaust ventilation, but you cannot have too much intake ventilation. If there is more intake ventilation than the attic's square footage requires, it's not problematic because any excess intake converts to “exhaust” on the leeward side of the house.

What happens if my roof is not vented?

They say that poor or non-existent ventilation might cause attic temperatures to rise to 150 degrees or higher in the summer. That can lead to damaged shingles and other roofing materials as well as a buildup of condensation and development of mildew and mold.

How do you know if your roof is properly vented?

How to determine whether you need better attic ventilation

Look at your eaves and roof. ...

Touch your ceiling on a warm, sunny day. ...

Warm air that escapes living space also carries moisture that will condense on rafters or roof sheathing.

Do I need to vent my garage roof?

Although venting the garage roof is not needed if you only park your vehicle in the garage, it is required by code to vent the attic if you insulate the attic floor. It is highly recommended you vent the garage roof when you have a common attic (no fire wall, making the attic open throughout) if you use it as a living space and want to keep the roofing in good condition.

How much attic ventilation is too much?

For most, the requirement is 300 to 1, meaning one square foot of ventilation is required for every 300 square feet of attic floor.