Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents.
Attic ventilation worksheet.
Attic ventilation calculator note.
Ridge vent must me installed per the manufactures instructions.
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.
Ridge vents are one of the easiest ways to meet roof venting requirements.
Let s look at the following example.
Most building codes require a ratio of 1 150 ventilation space to attic floor space.
Up to 6 12 7 12 to 10 12 11 12 and up.
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.
Jones has an attic space that measures 23 feet by 48 feet.
Select the roof pitch that is closest to yours.
You can also contact your local municipality to check on building code in your area.
Calculations are based on 1 square foot of net free area for every 150 square feet of attic floor space.
Other options to meet your attic ventilation needs are.
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.
This yields a total area of 1 104 square feet.
Of attic space 1 150 ventilation ratio measured at the attic floor level ceiling.
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.
The ridge vent is installed on the peak with nails and shingled over for aesthetic purposes.
Gaf attic ventilation calculator.
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.
Insulation at least r 38 or more is there for heating and.
Enter the width and length of your home including overhang in feet.
The attic ventilation worksheet shall be completed by the contractor applicant to determine the number of vents required to comply with minimum building code requirements.
It can do both.
Use this calculator to help determine the proper amount of attic ventilation based on u s.
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.
See attached required attic ventilation shall be provided for all reroof projects as determined from the attic ventilation worksheet.
Best ventilation is open soffit venting to a open vented ridge vent.
Standard attic vents like af 50 s ventilation fans or solar powered attic fans.
