How do I know if my New Brunswick home has adequate air sealing? | Insulation IQ?

Most New Brunswick homeowners don't know their home has an air sealing problem — they just know it feels drafty in January, their heating bills seem high, and some rooms are never quite comfortable no matter how the thermostat is set. The connection between those symptoms and air leakage through the building envelope often goes undiagnosed for years, quietly costing hundreds of dollars per winter.

The definitive test is a blower door test, performed by a certified energy adviser as part of an EnerGuide home evaluation. A blower door is a calibrated fan mounted in an exterior door frame that depressurizes the house to a standard 50 Pascals of pressure differential. The machine measures how much air is flowing through the fan to maintain that pressure — the higher the flow, the leakier the house. Results are reported in ACH50 (air changes per hour at 50 Pa) or ELA (equivalent leakage area). In New Brunswick's climate zone 6, new homes built to the NBC 9.36 energy efficiency requirements must achieve 3.5 ACH50 or better, and homes qualifying for the Canada Greener Homes Grant need to demonstrate improvement toward or below 5.0 ACH50 in a before-and-after test sequence.

Older homes in Moncton, Fredericton, or Saint John commonly test at 8–15 ACH50, meaning the entire air volume of the house is replaced by cold outdoor air 8 to 15 times every hour when the wind is blowing at pressure. Translated into practical terms: that's roughly equivalent to leaving a window open all winter.

Beyond the formal blower door test, there are observable signals that point to inadequate air sealing:

Ice dams forming on the eaves after snowfall are almost always an air sealing problem at the attic floor. Warm air escaping through gaps around pot lights, attic hatches, top plates, and electrical boxes heats the underside of the roof deck, melting snow that then refreezes at the cold eave overhang. Fredericton and Edmundston homeowners see this frequently after freeze-thaw cycles.

Frost or condensation on interior surfaces, particularly on the upper sections of exterior walls or around window frames in winter, signals that moist interior air is reaching cold surfaces — a clear sign the air barrier is not continuous. This is also a precursor to mould growth inside the wall cavity.

Visible daylight or cold air around electrical outlets on exterior walls, around the baseboards on above-grade walls in older homes with plank sheathing, or through attic access hatches are direct air leakage paths.

High heating bills relative to comparable homes. NB Power's online energy usage portal lets you compare your consumption year-over-year. If your home consistently uses 20–40% more energy than a similar-sized home built post-2010 in your area, air leakage is usually a significant part of the explanation.

The smoke pencil or incense test is a simple DIY diagnostic on a cold, windy day. Turn on all bathroom and kitchen exhaust fans to depressurize the house slightly, then hold a stick of incense near suspect locations — electrical outlets, where walls meet the ceiling, around window and door frames, at the base of exterior walls. Smoke that pulls toward the surface or is deflected by incoming air identifies the leak.

Common high-leakage locations in New Brunswick homes include: recessed lighting fixtures in attic floors (each unsealed pot light is roughly a 2-inch hole through the air barrier), rim joists at foundation level where the floor framing meets the foundation wall, attic access hatches (often just a bare piece of plywood with no weatherstripping), top plate penetrations for wiring and plumbing, and in older homes with balloon framing, open stud bays that run from basement to attic without any barrier.

If your home was built before 1985 and has never had an air sealing upgrade, it almost certainly fails modern standards. The original poly vapour barriers installed in NB homes of that era were often torn, improperly lapped, or terminated with staples rather than acoustic sealant — they provided some vapour control but minimal air barrier function.

The good news is that targeted air sealing is often the highest-ROI upgrade available to NB homeowners. Sealing the rim joist, attic floor bypasses, and recessed lights alone can reduce heating costs by 10–20% in many homes. When combined with NB Power's Home Energy Efficiency Program rebates and the federal Canada Greener Homes Grant (up to $5,600 for qualifying retrofits), the payback period on a comprehensive air sealing project is frequently under five years.

A qualified energy adviser from the New Brunswick Construction Network directory can arrange a blower door test and produce a prioritized retrofit plan specific to your home.

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Looking for experienced contractors? The New Brunswick Construction Network connects homeowners with qualified professionals:

• moose luxury painting
• Thirty Four Renovations
• Arctic Fox Construction Inc.
• 3Tone Construction Ltd
• Brunswick insulation & roofing