If you feel drafts in winter or rooms swing hot and cool through the day, it is time to look at insulation and air sealing. For Toronto homes, stopping air leaks and adding the right insulation in the right places is the highest value upgrade you can make. This guide explains where to start, how to pair air sealing with insulation, what materials work here, and what budgets and timelines to expect.

Start with priorities

1. Air seal first: Close gaps at the top and bottom of the house so the stack effect does not pull warm air out and cold air in.
2. Attic second: Most homes have the best return on investment by air sealing, then topping up attic insulation.
3. Rim joists and basements: Seal and insulate the band at the top of foundation walls and the first 2 feet of basement walls to cut drafts at floors.
4. Walls next: Dense pack or exterior insulation upgrades deliver comfort and sound reduction on older homes.
5. Ventilation: Add or tune HRV or ERV and spot fans so fresh air is controlled and indoor humidity stays in range.

Attic upgrades that actually work

• Air sealing checklist: Seal around plumbing stacks, electrical boxes, bath fan housings, top plates, and chases. Add weatherstripping at the attic hatch.
• Insulation target: Aim for R‑60 total in most Toronto houses. That usually means adding blown cellulose or fiberglass on top of existing insulation after air sealing.
• Baffles and vents: Keep soffit vents clear with baffles and provide a clear path to the ridge or roof vents.
• Recessed lights: Swap old cans for IC‑rated, airtight fixtures or cover with rated boxes and seal before insulating.

Rim joists and basements

• Rim joists: Use 2-inch rigid foam seams sealed with foam or use closed‑cell spray foam for an air‑tight, high R solution. Fiberglass alone here does poorly because moving air defeats it.
• Basement walls: For dry basements, a continuous layer of rigid foam or spray foam against the concrete with taped seams, then stud wall and batt or no batt as space allows. Do not place poly directly against concrete, which can trap moisture.
• Floors over crawls or porches: Add rigid foam to the underside with sealed seams and protect with an appropriate fire barrier where required.

Walls and exterior insulation

• Dense pack cellulose: For older walls, dense pack through small holes fills cavities and reduces drafts with minimal interior disruption.
• Exterior insulation: When replacing siding, add 1 to 2 inches of exterior mineral wool or foam, then furring and cladding. This reduces thermal bridging and pairs well with new windows.
• Air barrier continuity: Tie window flashings, housewrap, and tapes together so the air barrier is continuous around the whole shell.

Materials in plain language

• Blown cellulose: Recycled content, good at filling irregular spaces, great for attics.
• Blown fiberglass: Light and quick, stable R value, also good for attics.
• Rigid foam (XPS, EPS, polyiso): High R per inch, useful for basements and exterior. Polyiso performs best above grade.
• Mineral wool: Fire resistant, sound absorbing, and vapor open. Excellent for exterior layers and interior stud bays.
• Spray foam: Highest air sealing in hard-to-reach areas like rim joists. Use where it delivers unique value and balances with other materials elsewhere.

Condensation and moisture control

• Warm side control: Use a smart vapor retarder on the interior in renovation assemblies that need it.
• Bulk water first: Fix roof and window leaks before insulating.
• Dehumidification: Keep basements around 45 to 55 percent relative humidity to protect finishes.
• Bath and range fans: Vent outdoors and use timers or humidity sensors.

Budgets and timelines in Toronto

Every home is different, but these planning ranges help set expectations:

• Attic air sealing and top up to R‑60: $1,800 to $4,500, depending on access, depth, and fixtures.
• Rim joist air seal and insulate: $900 to $2,500, depending on length and approach.
• Basement wall foam and frame (per linear foot): $85 to $150, depending on thickness and finish.
• Dense pack wall cavities (per 100 sq ft): $700 to $1,400, depending on access and patching.
• Exterior insulation added with re‑clad (typical semi): $18,000 to $40,000, depending on thickness and cladding choice.

Typical timelines: 1 day for small attic jobs, 2 to 4 days for attic plus rim joists, 1 to 2 weeks for basement wall upgrades, and 2 to 4 weeks when paired with exterior re‑cladding.

Avoid these common mistakes

1. Blowing insulation into an attic without sealing big air leaks first.
2. Using poly against the basement concrete and trapping moisture.
3. Skipping baffles so soffit vents get blocked.
4. Forgetting to seal the attic hatch, which becomes a chimney for heat loss.
5. Ignoring ventilation, then wondering why windows sweat in winter.

Helpful companion reads on our site:

• Toronto Ice Dam Prevention 2025
• Windows That Work in Toronto 2025
• Toronto Heat Pump & HVAC Retrofit Guide 2025
• Toronto Home Flood Protection 2025

Ready to cut drafts and bills? Contact us today to book a consultation. We will assess your home, map the air sealing plan, and deliver insulation upgrades that feel better from day one.

📞 Call us at: 437-259-9632

✉️ Email us at: jgcontractingyyz@gmail.com

🌐 Website: https://jgcontractingyyz.com