{"id":6,"date":"2026-09-15T00:31:53","date_gmt":"2026-09-15T00:31:53","guid":{"rendered":"https:\/\/division7.ca\/blog\/?p=6"},"modified":"2026-09-15T00:46:57","modified_gmt":"2026-09-15T00:46:57","slug":"air-sealing-before-attic-insulation-bc","status":"publish","type":"post","link":"https:\/\/division7.ca\/blog\/air-sealing-before-attic-insulation-bc\/","title":{"rendered":"Why Air Sealing Matters Before Adding Attic Insulation in BC Homes"},"content":{"rendered":"

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Adding more insulation to an attic can be one of the most effective ways to improve comfort in a BC home, but insulation alone is not always the whole solution. Before topping up an attic with blown-in cellulose or fiberglass, it is worth checking for air leakage between the living space and the attic.<\/p>\n

Air sealing and insulation do different jobs. Insulation slows heat flow through the building assembly. Air sealing reduces the uncontrolled movement of indoor and outdoor air through gaps, penetrations, cracks, and openings. When both are addressed together, the attic assembly can perform much better than it would with insulation alone.<\/p>\n

Why attic air leaks matter<\/h2>\n

Warm indoor air naturally finds paths toward colder areas of the building. In winter, gaps around electrical penetrations, plumbing stacks, attic hatches, exhaust ducts, framing joints, and other openings can allow conditioned air to leak into the attic. In summer, hot attic air can also move into the living space through the same pathways.<\/p>\n

Those leaks can contribute to uneven room temperatures, drafts, higher heating or cooling demand, and moisture movement into the attic. Adding a thick layer of insulation may slow heat transfer, but it does not automatically stop air from moving through hidden gaps below it.<\/p>\n

Common attic leakage points<\/h2>\n

Every house is different, but several locations are worth inspecting before an insulation top-up:<\/p>\n