Formula For Proper Attic Ventilation

The house measures 30 feet by 50 feet.

Formula for proper attic ventilation.

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. 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.

Cool air in hot air out. 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. Here are the answers to the five most frequent questions pertaining to calculating attic ventilation. Divide the attic s square footage by 150.

Daily activities in your home such as showering dishwater laundry or having the furnace on generate heat and moisture in the air. Calculate or enter the square footage of the attic or area to be vented. The federal housing administration recommends 1 square foot of attic ventilation for every 150 square feet of attic space. Ft you would need at least 5 2 sq.

Attic mold rotting of roof sheathing and framing shortened roof life cracked paint and siding failure or an overheated home. Calculation q a. Ventilation of attic spaces is required by most building codes as well as by roofing material manufacturers and the national roofing contractors association nrca. Soffit vents alone are not enough to provide proper attic ventilation.

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. The majority of the requirements related to attic ventilation have not changed much from the previous editions. Let s use the following simple ranch house for an example. The following are the requirements taken directly from the irc.

Ok to determine how much ventilation area you need for your house all you need to know is the square foot area of the attic to be ventilated. Of vent area with half under the eaves in the soffit and half near the peak as either gable or ridge vents. Before we explore how to ventilate an attic space it is prudent to understand how much ventilation is needed. The ventilation amount and opening size requirements can be found in section 806 roof ventilation of chapter 8 roof ceiling construction.

For a 30 x26 attic 780 sq.