For minimum building code requirements use the 1 300 ratio instead of the 1 150 ratio.
Attic ventilation requirements ontario.
Intake vents located at the lowest part of the roof under the eaves allow cool.
Bathrooms can only benefit from some type of exhaust venting system but which type do you need and what does the bathroom exhaust fan venting.
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.
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 key to proper ventilation of your roof and attic is balance.
Ridge static attic vents 384 00 minimum sq.
Code requirements the international building code.
However in canada the largest contributor to infiltration is the temperature difference between the inside of the house and the outside causing in a phenomenon called stack effect.
Air vent recommends 1 square foot of ventilation for every 150 square feet of attic floor space with half the ventilation represented by intake vents and half by exhaust vents such as ridge vents.
Bathrooms are wet smelly places that often are closed in and unventilated.
Vent requirements 1 except as provided in sentence 2 the unobstructed vent area shall be not less than 1 300 of the insulated ceiling area.
Typically building codes include minimum requirements applicable to attic ventilation.
The ontario building code vent requirements 9 19 1 2.
Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents.
For the 1 150 attic ventilation requirement simply double the amount of exhaust and intake calculated.
Moisture though is the real problem since it can create potentially hazardous mold and mildew eating away at your walls ceiling and trim.
You can calculate attic ventilation requirements by determining the square footage of your attic.
The roofing industry also has practical guide lines for attic ventilation.
Smells are merely an annoyance.
As ventilation rates vary with wind speed and direction the magnitude of natural ventilation is difficult to predict.
Proper attic ventilation can be an impor tant performance consideration when design ing and installing steep slope roof systems.
Of net free area of exhaust needed at or near the ridge.
2 where the roof slope is less than 1 in 6 or in roofs that are constructed with roof joists the unobstructed vent area shall be not less than 1 150 of the insulated ceiling area.
