Insulation Contractors near you

Heat always moves toward the cold, so the envelope loses it wherever insulation is thin, missing or compressed, and wherever framing, concrete or metal forms a bridge straight to the outside. Air leakage adds to the loss: Natural Resources Canada lists typical leakage points such as the joint between the sill plate and the foundation, holes for wires and pipes, electrical outlets, window and door frames, attic hatches and chimneys.

Insulating value is given as RSI in metric units or as an R-value in imperial units, as in Natural Resources Canada's retrofit guide; either way, a higher number means more resistance to heat flow. The right material depends on access, moisture and whether it must also stop air.

Natural Resources Canada calls air leakage control the single most important retrofit activity and says it should be considered first in any upgrade strategy. Fibrous insulation slows heat but doesn't stop air, so an unsealed house keeps pushing warm, moist air into its walls and attic, where it can condense.

Walls are the hardest part of an existing house to insulate because they are closed. When the finishes are sound, a contractor can drill small holes and dense-pack cellulose, glass fibre or an approved foam into each cavity; NRCan advises writing the manufacturer's recommended density into the contract, since too little leaves voids and too much can bulge the wall. Shallow older stud cavities limit the gain.

When walls are gutted or the siding comes off, a deeper upgrade is possible: new batts or spray foam with a continuous air and vapour barrier inside, or rigid insulation and a new air barrier outside, which NRCan notes lets the existing interior vapour barrier stay. Either way, fix moisture or structural problems such as rot, mould or out-of-square windows first, and never fill the drainage cavity behind brick veneer or plug its drain holes.

Below grade, moisture comes first. NRCan advises against insulating a basement from the inside while it shows leaks, dampness, efflorescence or blistering paint, because interior insulation makes the foundation colder and can hide the water. Exterior insulation protects the foundation but requires excavation, so it usually goes with waterproofing or drainage work; interior insulation can be done in any season and fits a basement finish.

The rim joist, the band of framing on top of the foundation under the main floor, is one of the coldest and leakiest spots in many houses. NRCan describes sealing every joint between the subfloor, joists and foundation before insulating, with the air and vapour barrier continuous from the wall into this header space; spray foam applied by a certified installer often does both. In a crawl space, NRCan generally favours insulating the walls rather than the floor above, over a ground cover of 0.10 mm (4 mil) polyethylene overlapped, caulked and taped at the seams.

A tighter house keeps more moisture inside. NRCan warns that as the envelope is tightened, household humidity rises and can create condensation and moisture problems, which is why controllable whole-house ventilation, such as a heat recovery ventilator or properly sized exhaust fans, belongs in a thorough air sealing job. Winter is when this shows: frost in window corners or damp closets after a retrofit are signs the ventilation needs attention.

Fuel-burning appliances need air as well. NRCan explains that furnaces, water heaters, fireplaces and wood stoves need combustion air, and that in a closed-up house, exhaust fans can reverse the flow in a chimney or vent and spill combustion gases indoors. After major air sealing, have a qualified technician test naturally vented appliances for backdrafting, keep working smoke and carbon monoxide alarms, and consider sealed-combustion, direct-vent equipment when those appliances are replaced.

Health Canada notes that vermiculite-based insulation may contain asbestos and that it can be found in walls as well as attics. If you have it, don't disturb it or try to remove it yourself, and hire professionals trained to handle asbestos before any renovation that could reach it, including drilling into a wall to blow in new insulation. Health Canada adds that, before 1990, asbestos was mainly used to insulate buildings and homes against cold and noise, and it lists pipe and tank insulation, furnaces and heating systems among the places where it may turn up.

An EnerGuide home evaluation is the most useful starting point for a whole-house insulation project. An energy advisor registered with Natural Resources Canada, representing the service organization you choose, visits the house, measures its airtightness with a blower door test, records the insulation levels of the walls, ceilings and basement along with the heating equipment, and gives you an EnerGuide rating and a report of recommended upgrades. Many incentive programs require this evaluation before the work starts and a second one afterward.

Programs change often, so check what is open when you plan the work. Quebec's Rénoclimat program, which was active when this page was reviewed, pairs evaluations before and after the retrofits with financial assistance for insulation, airtightness and other upgrades. The federal Canada Greener Homes Affordability Program was also delivering no-cost retrofits, such as insulation, to low-to-median-income households through participating provinces and territories, including Quebec, with applications made through the provincial or territorial program.