Our Blog

How to Air Seal an Attic

Air leaks in the attic can be a large source of energy loss in the home. Sealing these leaks with caulk and weatherstripping can be done on your own, or you can have a professional contractor do it for you. Here are the basic steps regarding how to air seal an attic:

Sealing the attic

If you attempt this yourself, do it on a cool day and have someone who can help you in case you run into any problems. If your attic is large, you might wish to split this job up and do only a section at a time per day. Wear a dust mask and goggles to protect yourself from dust and debris.

  • Attic hatch: An attic hatch or entry door is often a large source of drafts. Because the hatch needs to remain moveable, place weatherstripping around it instead of using caulk.
  • Chimney shaft and flue: Caulk around all chimney shafts and flues.
  • Ductwork: Use caulk where ductwork enters the attic.
  • Plumbing vents: Wherever any flues, vents or pipes enter the attic, consider these areas to be potential sources of air leakage. Seal around these with caulk.
  • Recessed lights: Small gaps are common around recessed light boxes.  Use caulk or weatherstripping.

After you have sealed all of the obvious areas of potential air leaks, move around the attic slowly to check for any additional drafts. If you hear wind whistling or feel air movement that is not coming from attic vents, look for the source and seal it.

For more about how to air seal an attic and other issues related to home comfort and energy efficiency, please contact us today at HVAC & Plumbing Unlimited. We serve customers in Fairfax, Arlington, Alexandria, Springfield, Reston, Centreville, Lorton, Burke and Ashburn, Va., and other nearby areas.

HVAC Unlimited Inc.
Great job!
Steele - Woodbridge, VA
Ask about our special financing for 3 years with approved credit!
Accreditations & Affiliations