You will need a baffle for each space between the rafters.
Attic baffles requirements.
Attic ventilation system with built in baffle 10 per carton 4 4 out of 5 stars 3 accuvent 14 5 x 50 16 o c flame retardant pvc high energy vent 50 pack acbp18429.
Pull any existing insulation away from the edges of the attic where you will be putting up the baffles.
Surprisingly even the most well insulated attic space may still require the assistance of attic baffles to provide the additional air circulation.
Of total vent space needed.
That airflow is intended to churn the stale air in.
Each bag lists the required depths for a range of r values and the number of bags needed to cover 1 000 square feet at those depths.
Ado products durovent 23 1 2 in.
Calculate the total vent area needed.
That means drawing air in from outside the home and allowing it to push through the attic.
Length x width of attic in feet 150 total sq.
Multiply the length of the attic times the width in feet to find the attic area then divide by 150 to find the total square feet of vent space needed.
Baffles are a critical component to our attic insulation process that provides multiple benefits to a difficult construction aspect.
The picture below courtesy of the epa indoor airplus program which we provide builder verification services for helps show how the system works.
While it may seem counterintuitive even well insulated attic spaces require air circulation.
Attic baffles how they work.
A 50 x 30 attic would have a total area of 1 500 sq.
Measure your attic s square footage.
Attic ventilation works on the principle that heated air naturally rises primarily utilizing two types of vents.
For loose fill read labels.
Rafter vents or insulation baffles install in any rafter space.
You can situate the baffles where the circulation is mainly required.
Fit each one snuggly in the bay with the bottom starting where the ceiling joist meets the roof rafter.
For batts or rolls calculate the number based on the width and length of the product you re using.
The main function of an attic baffle is to draw the air in from outside your home and allowing it to circulate around your attic.