What is the correct order of priority for air sealing?

What is the correct order of priority for air sealing?

• A. Seal the Top, then the Bottom, then the Vertical Shafts, then Everything Else.
• B. Seal the Bottom, then Top, then the Vertical Shafts, then Everything Else
• C. Seal Everything Else first
• D. Seal Vertical Shafts first

Answer: (A)

Prioritizing air sealing by starting at the top and moving downward targets the largest and most influential leakage paths first. Sealing the attic and roof areas stops the major source of warm air escaping upward, which has a big impact on reducing overall heat loss. Next, addressing the bottom helps prevent cold air intrusion from the foundation and basement areas, cutting down drafts at the ground level. After those major paths are closed, sealing vertical shafts stops air from moving between floors through stairwells and service chases, which can undermine sealed zones above and below. Finally, you finish with everything else because these remaining penetrations are typically smaller and easier to seal once the big leaks are already minimized.

Prioritizing air sealing by starting at the top and moving downward targets the largest and most influential leakage paths first. Sealing the attic and roof areas stops the major source of warm air escaping upward, which has a big impact on reducing overall heat loss. Next, addressing the bottom helps prevent cold air intrusion from the foundation and basement areas, cutting down drafts at the ground level. After those major paths are closed, sealing vertical shafts stops air from moving between floors through stairwells and service chases, which can undermine sealed zones above and below. Finally, you finish with everything else because these remaining penetrations are typically smaller and easier to seal once the big leaks are already minimized.