Glossary

Home inspection glossary

Report terms explained in plain language.

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Terms

Aluminum wiring: Branch wiring made of aluminum instead of copper, used in some homes built in the late 1960s and 1970s. Connections can loosen and overheat if they are not made with the right parts, so it is worth having an electrician review.
Asbestos: A mineral fibre once used in insulation, flooring, ceiling texture and pipe wrap. It is only a concern when disturbed. An inspection can note materials that may contain it, but only a lab test can confirm it.
Attic bypass: A gap where warm, moist house air leaks into the attic, such as around light fixtures, plumbing stacks or the attic hatch. In cold weather that moisture can form frost and lead to stains or mould.
Backflow valve (backwater valve): A valve on the main sewer line that lets wastewater leave the house but closes if the city sewer backs up. Many Edmonton homes have one; it needs occasional cleaning.
Efflorescence: A white, powdery deposit on concrete or masonry left behind when water moves through it and evaporates. It is a sign of moisture, not damage in itself.
Flashing: Thin metal or membrane that directs water away from joints, such as where a roof meets a wall or around a chimney.
Freeze-thaw cycle: Water that soaks into concrete, masonry or soil freezes, expands and thaws again. Repeated through an Alberta winter, it widens cracks and moves steps, walkways and foundations.
GFCI outlet: A ground fault circuit interrupter outlet cuts power quickly if electricity leaks to ground, which protects against shock. They are expected near water, such as in bathrooms, kitchens and outdoors.
Grading: The slope of the ground around a house. Good grading slopes away from the foundation so water drains away instead of toward the basement.
Heat exchanger: The part of a furnace that transfers heat from the burner to the air in your home while keeping combustion gases separate. A visual inspection cannot confirm it is free of cracks; a furnace technician can.
HRV (heat recovery ventilator): A ventilation unit that brings in fresh outdoor air and exhausts stale indoor air, using the outgoing air to warm the incoming air. Common in newer, tighter homes; its filters need regular cleaning.
Ice damming: A ridge of ice that forms at the edge of a roof when heat from the house melts snow higher up and the water refreezes at the cold eaves. Water can back up under the shingles and leak inside.
Knob-and-tube wiring: An early wiring method with single wires on porcelain knobs and tubes, found in some homes built before about 1950. Many insurers ask about it, and it is usually recommended for evaluation by an electrician.
Parging: A thin coat of cement-based mortar on the exposed outside of a foundation wall. Cracked or loose parging is mostly cosmetic but can let water reach the wall behind it.
Poly-B (polybutylene) pipe: Grey plastic water supply pipe used in many homes built from the late 1970s to the mid-1990s. Some fittings have a history of failing, and some insurers ask about it or charge more.
Radon: A colourless, odourless radioactive gas that comes from the ground and can build up in basements. The only way to know a home’s level is a radon test, which takes longer than an inspection.
Reverse grading (negative grading): Ground that slopes toward the house instead of away from it, often because backfill around the foundation has settled. It sends water toward the basement.
Sewer scope: A camera inspection of the main sewer line from the house to the city connection. It finds roots, breaks, sags and old clay or cast-iron pipe that a home inspection cannot see.
Shingle granule loss: Asphalt shingles shed their protective granules as they age. Bare or smooth patches and granules collecting in the gutters are signs the roof covering is nearing the end of its life.
Spalling: Concrete or brick flaking or breaking away at the surface, often from moisture and freeze-thaw cycles.
Sump pit and pump: A pit in the basement floor that collects groundwater from the weeping tile, with a pump that pushes it outside. A missing or failed pump is a common cause of basement water.
Vapour barrier: A layer, usually plastic sheeting, that slows moisture moving from the warm inside of a home into walls and ceilings, where it could condense in cold weather.
Vermiculite insulation: A loose, pebble-like attic insulation that is grey-brown or gold. Some vermiculite contains asbestos, so it should be left undisturbed until tested.
Weeping tile: A perforated drain pipe around the base of the foundation that collects groundwater and carries it to a sump pit or, in older homes, the sewer.
Window well: The pit around a basement window below ground level. It should be clear of debris, drain well and ideally have a cover, or it can fill with water and snow.