Formula For Proper Attic Ventilation

Proper attic ventilation consists of a balance between air intake at your eaves soffits or fascias and air exhaust at or near your roof ridge.

Formula for proper attic ventilation.

Let s use the following simple ranch house for an example. Most attic ventilation manufacturers list the longer formula on their websites and inside key product brochures. Ventilation can be accomplished using various products and techniques. Federal housing authority recommends a minimum of at least 1 square foot of attic ventilation evenly split between intake and exhaust for every 300 square feet of attic floor space.

But the shortcut is just as good and faster. The federal housing administration recommends 1 square foot of attic ventilation for every 150 square feet of attic space. The following are the requirements taken directly from the irc. Calculate or enter the square footage of the attic or area to be vented.

Of vent area with half under the eaves in the soffit and half near the peak as either gable or ridge vents. Soffit vents alone are not enough to provide proper attic ventilation. The majority of the requirements related to attic ventilation have not changed much from the previous editions. For a 30 x26 attic 780 sq.

Calculating ventilation area of attic kitchen ventilation text. Attic mold rotting of roof sheathing and framing shortened roof life cracked paint and siding failure or an overheated home. Calculation q a. Ft you would need at least 5 2 sq.

Proper air ventilation in the roof prevents costly problems like. Ensuring your home has the proper attic ventilation according to these guidelines however can save yourself the stress and hassle of an emergency roof repair. Here are the answers to the five most frequent questions pertaining to calculating attic ventilation. The house measures 30 feet by 50 feet.

Cool air in hot air out. Divide the attic s square footage by 150. Let owens corning roofing help you calculate exactly how much ventilation you will need for a healthy and balanced attic with our 4 step ventilation calculator. The ventilation amount and opening size requirements can be found in section 806 roof ventilation of chapter 8 roof ceiling construction.

Before we explore how to ventilate an attic space it is prudent to understand how much ventilation is needed.