Ventilation of attic spaces is required by most building codes as well as by roofing material manufacturers and the national roofing contractors association nrca.
Why do you need ventilation in the attic.
All you need to know about attic ventilation understand the pieces and parts that contribute to quality attic ventilation so that you can better cool down the space and prevent roof damage all.
Effective ventilation provides year round benefits creating a cooler attic in the summer and a drier attic in the winter.
Throughout the balance of this digest the terms attic and roof will and can be used interchangeably.
Good insulation reduces fan effectiveness.
How much venting do you need.
In cold climates the primary purpose of attic or roof ventilation is to maintain a cold roof temperature to control ice dams created by melting snow and to vent moisture that moves from the conditioned space to the attic ventilation acts to bypass the vapour barrier created by most roof.
Generally speaking you need a ratio of 1 300 where for every 300 square feet of ceiling space you need 1 square foot of attic ventilation.
Rarely will you find a building practice that works everywhere.
Federal housing administration recommends a minimum of at least one square foot of attic ventilation split evenly between intake and exhaust for every 300 square feet of attic floor space.
In other words the entire vent opening doesn t count as vented space.
Attic ventilation fans whether hard wired or powered by their own solar panels seem like a low cost and effective way to help keep your house cool.
This 1 300 rule is general and may not apply to all buildings.
Attic fans are intended to cool hot attics by drawing in cooler outside air from attic vents soffit and gable and pushing hot air to the outside.
How you can improve your attic ventilation.
The downside of attic ventilation fans.
For instance attic ventilation is used widely in cold climates to evacuate the warm moist air that escapes from the living space below.
That said air resistance and interference such as vent grates reduces the area of true ventilation.
Ventilation can be accomplished using various products and techniques.
It s typically the minimum recommended standard that should be used for ventilating attics.
One reason for the lack of agreement over attic ventilation is the tremendous variation in climate across north america.
However the utility of attic ventilation fans is actually quite a controversial topic.
However if your attic has blocked soffit vents and is not well sealed from the rest of the house attic fans will suck cool conditioned air up out of the house and into the.
What does attic ventilation do for my home.
The size and placement of vents depends on the roof configuration and the size of the attic.