The 6-Point Pre-Winter Roof Checklist
A thorough pre-winter inspection covers six key areas. Each one addresses a specific failure mode that Quebec's freeze-thaw cycles and heavy snowfall tend to exploit.
1. Inspect Shingles and Membrane
Look for cracked, curled, or missing shingles. On flat roofs, check for blisters or cracks in the membrane. Check your gutters for granule accumulation — heavy granule loss signals shingles approaching the end of their service life. Any compromised area will worsen dramatically under snow load and freeze-thaw cycles.
2. Check and Replace Flashings
The majority of roof leaks originate at transitions — chimney bases, skylight perimeters, and wall-roof intersections. Inspect metal flashings for lifting, rust, or gaps. If the caulking around these areas is cracked or pulling away, reapply with a roofing-grade sealant before temperatures drop below 5°C, which is the minimum application temperature for most sealants.
3. Clean Gutters and Downspouts
Clogged gutters are a leading cause of ice dams. When gutters overflow with debris, water backs up and freezes at the roof edge, forcing ice under the first courses of shingles or under the membrane edge. Clean gutters after leaves have fully fallen — late October to early November in the Montreal and South Shore area. Confirm downspouts discharge water at least 1.5 m away from the foundation.
4. Verify Attic Ventilation
Proper attic ventilation keeps the roof deck cold and uniform in temperature — the key to preventing ice dams. The system relies on balanced intake at the soffits and exhaust at the ridge or roof vents. A very common problem is insulation installed directly against soffit vents, blocking intake airflow entirely. Confirm baffles are in place to keep soffit vents clear.
5. Check Attic Insulation Level
The Quebec building code sets a minimum of R-41 for attic insulation; R-50 (RSI 8.8) is strongly recommended for existing homes in our climate. Inadequate insulation allows heat to escape from your living space, warming the roof deck from below and triggering the melt-refreeze cycle that creates ice dams. Check your current depth — 30 cm of blown-in cellulose or fiberglass provides approximately R-41. See our guide: Ice Dams: Causes, Prevention and Solutions.
6. Inspect the Interior
Before winter arrives, inspect your attic and ceilings from the inside. Water stains on ceilings — even old, dry ones — indicate past infiltration points. Damp or compressed insulation in the attic signals ongoing moisture intrusion. A musty smell in the attic suggests mold growth, which often develops unseen after a slow, long-term leak. These signs require immediate attention before snow adds weight and hydrostatic pressure.
What Happens When You Skip Winter Preparation
Skipping the fall inspection doesn't save time — it defers costs while allowing damage to compound throughout the winter. Three specific failure chains are most common:
- Ice dam cascade: Unaddressed ventilation or insulation deficiencies allow ice dams to form. Water backs up under the roofing material, saturating the wood decking, soaking attic insulation, and eventually reaching interior ceilings. By spring, what was a $400 insulation fix has become a $5,000+ structural repair.
- Snow load risk: Accumulated snow over 60 cm (24") on a pitched roof or over 45 cm (18") on a flat roof begins to represent a structural concern — especially on older homes or buildings with already-compromised decking. A professional inspection can identify framing or decking weakness before it becomes a failure under load.
- Membrane crack propagation: Aging flat roof membranes with existing micro-cracks are vulnerable to Quebec's freeze-thaw cycles. Water enters existing cracks, freezes, expands, and widens them. What was a small crack in October can be a split seam by March. Sealing cracks before winter dramatically extends membrane life.
When to Call a Professional
A DIY visual inspection from the ground and from inside the attic is a valuable first step that every homeowner should do. Walk the perimeter of your home and look at the roofline; check the attic with a flashlight on a sunny day.
However, anything involving climbing onto the roof, assessing structural concerns, evaluating membrane integrity up close, or repairing flashings requires a licensed roofer with an RBQ (Régie du bâtiment du Québec) licence. Rooftop work is among the leading causes of serious injury in home maintenance — and a professional has both the safety equipment and the trained eye to catch what a ground-level inspection misses.
Winter is coming: If your roof needs snow removal during the season, our professional team handles it safely and without damaging the roofing surface. Learn about our roof snow removal service.
Professional Pre-Winter Inspection: What's Included
Our pre-winter inspection covers the full roofing system — not just a visual sweep from the ground. Here is what we assess on every visit:
Documented with photos of every identified deficiency, so you have a clear record before and after any repair work.
Non-destructive moisture detection to identify wet areas in the decking or insulation that are not yet visible from the interior.
All transition points checked: chimney, skylights, dormers, plumbing stacks, and wall-roof intersections.
Soffit and ridge vent verification, insulation depth measurement, and air leak identification.
Issues are classified as urgent (address before winter), recommended (address within 1–2 seasons), or advisory (monitor). No pressure — just honest information.
Our inspection and repair services are detailed on the Inspection and Repair page. We serve the Montreal and South Shore area with RBQ-licensed technicians.
Frequently Asked Questions
When should I inspect my roof before winter in Quebec?
September to mid-October is the ideal window, before temperatures drop below 5°C. Sealants and some repair materials require warmer temperatures to set properly. Waiting until November risks having to postpone work until spring — or dealing with winter damage that could have been prevented.
How much does a pre-winter roof inspection cost?
Typically $150–$350 for a professional inspection with a written report. Many contractors — including Toiture Qualité Pro — credit the inspection fee toward repair costs if you proceed with the recommended work. Considering the potential cost of water infiltration damage, it's one of the best investments a homeowner can make.
Can roof work be done in winter?
Yes. Membrane thermal welding works reliably in cold weather and is performed year-round. Shingle repairs can be done in mild winter conditions (above -10°C with proper material handling). Emergency repairs are always available regardless of season — a leaking roof in January still needs to be addressed immediately.