How to Close Off Attic Vents

Proper venting of your attic keeps your home warmer in the winter and cooler in the summer. It also prevents ice dams, a built up of snow that won’t melt, from forming on your roof. If your roof has too much ventilation, however, you could be losing heat in the winter and cool air in the summer. In order to fix that, you can close off some of your attic’s vents.

Measuring tape
Tarp
Duct tape

Instructions

- 1
  Measure the total square footage of your attic. Multiply the length of the attic by the width. For example, an attic that is 30 feet by 40 feet would have a square footage of 1,200.
- 2
  Divide the square footage by 150. For example, an attic with 1,200 square feet divided by 150 equals eight. This is how many attic vents you should have open at all times. Half of those should be intake vents and the other half exhaust vents.
- 3
  Close off any vents that are over the number of vents your attic needs for proper ventilation. Slide the vent adjustment bar closed, if your vents have one. If not, place a piece of tarp over the vent and tape it in place.

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