I added insulation to the attic rafters, but should I have left room for airflow

atticinsulation

I added insulation to my attic rafters and plugged the space between the outdoors and my attic with insulation. It lowered my heating bill by $150/month, but I've seen some information that I may have made a mistake by cutting off the airflow in my attic.

Did I make a mistake, and if so, how can I properly insulate my attic? There's already insulation in the floor.

Best Answer

You can buy air ducts that staple to the inside of your roof above the eave vents and fit between the rafters. The will hold open an air gap of approximately 1 inch to allow airflow past a layer of insulation. The ones I've used are made of styrofoam and IIRC they cost around $2. You should be able to find them near the insulation in your home improvement store.

EDIT: They are called baffles or rafter vents; this is how they're installed:

metal rafter vent between wooden roof and insulation