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Insulation

Attic air sealing

Both ENERGY STAR and Natural Resources Canada place air and moisture control ahead of simply adding more insulation. This worksheet counts and locates penetrations; it does not assign generic leakage rates or promise energy savings.

First answer

Inspect and address accessible air leakage and moisture pathways before adding insulation, while preserving required clearances, ventilation, and combustion safety.

Formula or decision rule

work-list total = sum of accessible penetrations by type and location; material quantity follows the selected sealant system label
  • A count is a project inventory, not an air-leakage measurement.
  • Recessed fixtures require their approved clearance or cover details.
  • Sealant compatibility and gap limits come from the chosen system.

Air-sealing map

Air-sealing map
LocationRecordBoundary check
Top plateslinear accessible jointsdry and reachable
Wiring/plumbingpenetration count and sizeapproved sealing system
Chases/soffitsopening dimensionsfire/combustion requirements
Attic hatchperimeter and paneloperable and insulated

Work through the project

  1. Trace the ceiling plane

    Sketch the conditioned-space boundary and mark penetrations visible from the attic and room side.

  2. Resolve hazards and moisture

    Stop for active leaks, suspect material, unsafe wiring, combustion venting, or required fire-protection details.

  3. Document before covering

    Photograph completed accessible work and keep product labels before insulation makes the plane hard to inspect.

Safety and scope

  • Never block required ventilation or cover a heat-producing fixture unless its approved detail allows it.
  • Combustion appliances, flues, and electrical conditions can require qualified trade work.

Sources and scope

Source links reviewed July 16, 2026. A review date is not the document's publication date.

  1. ENERGY STAR: Attic InsulationUnited States · government guide

    Air leaks and moisture conditions should be addressed before insulation is added.

  2. Natural Resources Canada: Keeping the Heat In — Roofs and atticsCanada · government guide

    Follow product labels for bag count and settled depth; do not disturb suspected vermiculite.