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Winter-Proofing Your Home in Montreal: Essential Renovations

 

ELIMINATING AIR LEAKS AND INSULATING YOUR HOME

Drafts, condensation, cold floors... If heat is escaping from your home, you need to use more energy to make up for the loss. Did you know that, in Québec, heating accounts for 50% of the energy used in a typical household?

If you are planning major home renovations, consider including work to minimize air leaks and heat loss through your home’s thermal envelope. By keeping heat inside your home in the winter, you’ll lower your energy use and your electricity bill!

 

 

Do you know how heat is escaping from your home?

If you plan to take advantage of your renovations to improve your home’s insulation, your first step will be to find out where you are losing heat. Energy efficiency advisors can guide you through any major project involving insulating your home or eliminating air leaks. They can help you assess the relevance of an insulation project in great detail, particularly if your home was built before 1980 and has never been renovated.

The two main points to consider are heat loss through your home’s thermal envelope and heat loss caused by air leaks. Do you know the difference?

Heat loss through the thermal envelope is any loss that occurs “through” your home’s surfaces. It tends to be greater if your home has large surfaces, if the difference between the indoor temperature and outdoor temperature is significant, and if the thermal insulation (also known as thermal resistance) of the surfaces is low.

The level of thermal insulation depends on the materials used to insulate your home’s external walls, roofs, exposed floors (on piles) and floors against the ground. A high level of thermal insulation limits the transfer of heat from inside the house to outside.

Heat loss caused by air leaks is any loss occurring from unintentional exchanges between indoor air and outdoor air, known as either air infiltration or exfiltration. There are many places in a home where these exchanges take place: the seals around doors and windows, chimneys, etc.

 

How to maximize your renovations with the Rénoclimat program

Carried out by certified advisors, the evaluation available under the program checks your home for air leaks and evaluates its overall energy efficiency. The insulation level recommended for your home is then presented to you, along with details on the energy you will save by implementing the changes suggested (kWh/year).

Once you know this information and the cost of the recommended changes, you’ll be better equipped to analyze the situation and make an informed decision about which improvements you wish to make.

Find out more about the Rénoclimat program

 

Insulating your thermal envelope: improving thermal resistance

Insulating materials are essential for improving your home’s thermal resistance.

Here are the most common types of insulation

Batt or blanket

Materials:

Fiberglass

Mineral fiber

Uses:

Inserted into the cavities of walls, roofs and framed floors.

Recommandations:

An air barrier and vapor barrier are required when using this type of insulation in walls and roofs. In floors, the rim joists need to be sealed using an air barrier, and the insulation must be covered with a vapor barrier on its interior surface.

The insulation must not come into direct contact with a concrete wall or a concrete floor against the ground: a humidity barrier is required.

Batt, blanket and loose-fill insulation is generally less costly per R value than rigid board or spray foam insulation.

Thermal resistance

MaterialsApproximate range
RSI/25.4mm (R/po)Indicative
RSI/25.4mm (R/po)

Fiberglass0.55-0.76 (3.1-4.3)0.62 (3.5)

Mineral fiber0.53- 0.70 (3.0-4.0)0.62 (3.5)

 

Loose-fill

Materials:

Blown cellulose fiber

Blown glass fiber

Blown mineral fiber

Uses:

Blown into the cavities of roof frames.

Recommandations:

Requires air and vapor barriers: the effectiveness of the air barrier in roofs must be ensured and the insulation must be covered with a vapor barrier on its interior surface.

If the insulation is applied in spaces other than the cavities of roof frames (in wall frames, for example), specific installation techniques must be used to limit the gaps caused by the settling of this material.

Blowing requires specialized equipment and workers.

Batt, blanket and loose-fill insulation is generally less costly per R value than rigid board or spray foam insulation.

Thermal resistance

MaterialsApproximate range
RSI/25.4mm (R/po)Indicative
RSI/25.4mm (R/po)

Blown cellulose fiber0.53-0.67 (3.0-3.8)0.62 (3.5)

Blown glass fiber0.48-0.63 (2.7-3.6)0.53 (3.0)

Blown mineral fiber0.53-0.67 (3.0-3.8)0.53 (3.0)

Rigid boards

Materials:

Expanded polystyrene (“bead” board)

Extruded polystyrene

Polyisocyanurate and polyurethane (covered with aluminum on both sides)

Uses:

Installed continuously across walls, floors and roofs.

Recommandations:

Extruded polystyrene boards have a low permeability. They do not absorb moisture or let it through easily.

These boards can be used for concrete walls and floors in contact with the ground. Certain high-density expanded polystyrene boards have been specifically designed for this purpose.

Be cautious and mindful when using these boards in anything other than frames with isolated cavities (minimum R value proportional to that of the cavity) in the same way one would with other boards, such as those covered with a low permeability material.

Extruded polystyrene boards and boards covered with an appropriate material can act as an air barrier if joints are sealed. At a certain thickness, they can also act as a vapor barrier.

The materials used on interior surfaces must be covered with a fire-resistant material.

These boards can be used for certain types of roofs (no-cavity or low roofs that are not accessible and do not allow for easy ventilation with outdoor air).

Rigid board and spray foam insulation are generally more costly per R value than batt, blanket and loose-fill insulation.

Thermal resistance

MaterialsApproximate range
RSI/25.4mm (R/po)Indicative
RSI/25.4mm (R/po)

Expanded polystyrene (“bead” board)0.67-0.77 (3.8-4.4)0.70 (4.0)

Extruded polystyrene0.88 (5.0)0.88 (5.0)

Polyisocyanurate and polyurethane (covered with aluminum on both sides)0.88-1.23 (5.0-7.0)1.06 (6.0)

Spray foam

Materials:

Polyurethane

Uses:

Sprayed continuously across the surface of walls (closed-cell structure, high density).

Recommandations:

Closed-cell polyurethane foam sprayed continuously may be used for:

insulating the interior surface of concrete walls in contact with the ground;

creating an air barrier and, past a certain thickness (about 2 in), a vapor barrier.

Polyurethane sprayed on an interior surface must be covered with a fire-resistant material.

Spraying should always be done by specialized and experienced workers using specialized equipment.

Allow a 24-hour off-gassing period before occupancy can resume.

Rigid board or spray foam insulation is generally more costly per R value than batt, blanket and loose-fill insulation.

Though not commonly used, low density open-cell polyurethane foam can be sprayed non-continuously into cavities. It can act as an air barrier but not a vapor barrier.

Thermal resistance

MaterialsApproximate range
RSI/25.4mm (R/po)Indicative
RSI/25.4mm (R/po)

polyurethane0.88-1.15 (5.0-6.5)1.06 (6.0)

If you do decide to improve the thermal resistance of your home, we recommend aiming for the thermal insulation levels required for new buildings.

 

 

Regulation in effect (since 2012)

Select a zone

                                                 Very cold winter..., ...Amos, Gagnon, Schefferville, …                                                 Cold winter…, …Montréal, Gatineau, Québec, Gaspé, Chicoutimi, …                                                 All                                             

Cold winter…, …Montréal, Gatineau, Québec, Gaspé, Chicoutimi, …

Components exposedRSItRt*

Roof or ceiling7.2241.0

Wall above ground level4.3124.5

*RSIt et Rt = Total thermal resistance

 

Creating an airtight envelope

Eliminating air leaks reduces heat loss and limits condensation in your home’s envelope.

You may need to carry out work to eliminate air leaks if:

Your home is older with many sources of air leaks, and work has never been done to improve its energy efficiency.

Condensation is detected in the exterior walls and roofs.

The inside of your home has too many cold drafts or is uncomfortably dry in winter.