How Many Vents Should A Roof Have

Feet of attic space divided 50 50.

How many vents should a roof have.

The size of your roof and attic space will determine how many roof vents you need. Foot of ventilation for every 150 sq. Ventsure 4 foot strip heat moisture ridge vent. Choose one of the following products to meet the recommended exhaust nfva of 528 square inches.

In our 2000 square feet example we determined we needed 480 square inches for intake 480 square inches for exhaust. Ventsure 4 foot strip heat moisture ridge vent with weather protector moisture barrier. If the home already has a fan roof vents or gable vents these should be blocked and sealed from the attic side of the home. Soffit vents are vital in keeping air flowing throughout your attic space.

You ll need the square footage of your attic to calculate the number of roof vents that you should need. Hot air exhaust vents located at the peak of the roof allow hot air to escape. Even if you have vents in your roof you still need to have soffit vents to allow the air to circulate naturally. There are a number of different types of vents to choose from so getting the ones to suit you should not be difficult although you will still need to work out how many to purchase.

Divide that by 144 for a 0 196 square foot opening. A 6 inch diameter soffit vent would have a 3 inch radius. Squaring the radius is 9 and multiplying it by pi is 28 26. Once the recommended amount of net free area is known and the type of vents have been selected you can determine how many vents you will need.

It should be noted that these vents which expel warm moist air from the bathroom and food prep areas of the home need their own ducts and vent hoods which direct air to the home s exterior. Taking advantage of this natural process referred to as passive ventilation is the most common way to vent an attic. Industry standard for proper attic ventilation recommends for no vapor retarder type of attic insulation no paper plastic or aluminum layer between the attic floor and insulation layer 1 sq. Attic ventilation requirements how many attic vents your roof needs.

These vents and ducts should never share space with the roof vent and air should never be vented directly into the attic. 27 lineal feet required. The next step is to divide the nfa required by the nfa rating of the vent. For example if you have 1200 square feet of attic space you should need at least 4 air vents to ensure proper ventilation.

Solid vinyl soffit material costs the same as the vented material.