Your Attic Might Need This Makeover Before Winter, by Home Comfort Guy on YouTube. 5 min 16 s.
- Video length
- 5 min 16 s
- Time to do it
- 3 to 4 hours
- Difficulty
- Medium
- Steps
- 8
What you need
Steps
Book an energy audit that includes a blower door test. The test pressurises the house so leaks show up, including ones you cannot spot from inside the attic.
Find the boundary between inside and outside. In most homes that is the attic floor, so the ceiling below is your air barrier, not the roof deck.
Walk the attic with a flashlight and check recessed lights, wiring holes, plumbing pipes, top plates and attic walls. These are the gaps most homeowners miss.
Check duct joints, including supply ducts someone already repaired. Run the system, push on the tape and feel for air, because gaps often survive a quick fix.
In a split-level home, check the attic space beside an upstairs bathroom. Hidden connections there can link the attic to the house and leak steadily.
Seal small gaps with expanding foam. Use the low-expansion type around windows and doors, and fire-rated foam around flues and chimneys.
Seal duct gaps with mastic or foil-backed tape, not plain cloth duct tape. Let it cure before you run the system again.
Ask what needs sealing before anything gets covered up. Get pictures of the gaps and the finished repairs so you know the work was actually done.
Tips and common mistakes
Never block soffit vents or bury the airflow path at the eaves under insulation.
Only seal around recessed lights rated airtight and IC, otherwise build a box or call an electrician.
Wear gloves, safety glasses and a dust mask, and step only on joists or a laid board.
Photograph each gap before and after sealing so you can show what changed.
Questions
Can I skip sealing and just add more insulation?
No. Insulation slows heat flow but does not stop air movement, so leaks keep carrying warm air out. Seal the gaps first, then add insulation.
Do I really need a blower door test?
It is the fastest way to find leaks hidden behind finished surfaces, and it gives you a before and after number. You can still seal obvious gaps yourself without one.
Which foam should I use?
Low-expansion foam for window and door frames, standard foam for framing gaps, and fire-rated foam around flues and chimneys. Read the can before you start.
This guide was drafted from the video's details and general task knowledge. It has not been checked against the full video. Check the video and relevant product instructions before following a procedure. Report a correction.
