Attic Ventilation Worksheet

Calculations are based on 1 square foot of net free area for every 150 square feet of attic floor space.

Attic ventilation worksheet.

Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents. Of attic space 1 150 ventilation ratio measured at the attic floor level ceiling. Ridge vents are one of the easiest ways to meet roof venting requirements. See attached required attic ventilation shall be provided for all reroof projects as determined from the attic ventilation worksheet.

Jones has an attic space that measures 23 feet by 48 feet. Furthermore nrca also rec ommends the amount of ventila. Attic ventilation calculator note. Let s look at the following example.

Other options to meet your attic ventilation needs are. Ridge vent must me installed per the manufactures instructions. Gaf attic ventilation calculator. Best ventilation is open soffit venting to a open vented ridge vent.

One last thought attic ventilation is not there to get rid of heat it is there to get rid of excess moisture accumulating from the home. Up to 6 12 7 12 to 10 12 11 12 and up. Insulation at least r 38 or more is there for heating and. Most building codes require a ratio of 1 150 ventilation space to attic floor space.

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. Enter the width and length of your home including overhang in feet. 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. Intake vents located at the lowest part of the roof under the eaves allow cool.

For large volume attics such as where roof slopes are greater than 8 12 designers also should consider increasing the amount of attic ventilation to account for the additional volume of attic space. Select the roof pitch that is closest to yours. Use this calculator to help determine the proper amount of attic ventilation based on u s. It can do both.

Standard attic vents like af 50 s ventilation fans or solar powered attic fans. This yields a total area of 1 104 square feet. Calculate or enter the square footage of the attic or area to be vented. The ridge vent is installed on the peak with nails and shingled over for aesthetic purposes.

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.