Asphalt Shingle Roofing
Asphalt shingles are the most common residential roofing material in Renfrew County, accounting for approximately 80–85% of homes. Three main types are available:
Three-Tab Shingles
Three-tab shingles are the entry-level option. They are flat, single-layer shingles that create a uniform appearance. They typically weigh 200–235 lbs per square (100 sq ft) and carry a 20–25 year manufacturer’s warranty, though in Renfrew County’s climate they last 12–18 years. They are the least expensive option but offer the lowest wind resistance and hail protection. Three-tab shingles are generally not recommended for Renfrew County given the region’s storm activity.
Architectural (Dimensional) Shingles
Architectural shingles are the standard recommendation for Renfrew County homes. They have multiple layers of shingle material laminated together, creating a three-dimensional appearance. Weight ranges from 280–350 lbs per square. They offer better wind resistance (up to 130 km/h or higher with proper installation), better hail impact resistance, and a longer lifespan of 18–25 years in Renfrew County. The additional cost over three-tab is approximately 15–25% and is widely considered worthwhile for this climate.
Impact-Resistant Shingles
Impact-resistant shingles carry a Class 3 or Class 4 rating (per UL 2218 or ASTM D3462). They incorporate modified asphalt and reinforcement for greater durability. These are an excellent choice for Renfrew County homes in areas prone to hail or falling debris. They add approximately 25–40% over standard architectural shingles but may qualify for insurance premium discounts. Class 4 shingles can withstand a 2-inch steel ball dropped from 20 feet without cracking.
Metal Roofing
Metal roofing represents a premium option that is gaining popularity in Renfrew County, particularly on rural properties with steep pitches where snow shedding is a priority.
Standing Seam Metal
Standing seam metal roofing uses interlocking panels with concealed fasteners. No exposed screw heads means fewer potential leak points. Panels run vertically from eave to ridge, allowing snow to shed efficiently. Standing seam systems cost approximately $12–$18 per sq ft installed, or roughly 1.5–2 times the cost of architectural shingles. Lifespan in Renfrew County is 40–60 years. The snow-shedding properties alone can justify the premium on steep-roofed rural homes.
Exposed Fastener (Corrugated) Metal
Exposed fastener metal panels use screws with neoprene washers driven through the panel face. This is a more affordable option at approximately $8–$12 per sq ft installed, but the exposed fasteners are vulnerable to thermal cycling and washer degradation over time. In Renfrew County’s freeze-thaw climate, exposed fastener panels require more maintenance than standing seam and are better suited to outbuildings, garages, or steep-slope applications where water runs off quickly.
Roof Pitch and Snow Shedding
Metal roofing requires a minimum slope for proper water and snow shedding. For standing seam, minimum slope is typically 3:12 (14 degrees). For exposed fastener panels, minimum is typically 4:12 (18 degrees). Many Renfrew County rural homes have pitches of 8:12 or steeper, which are ideal for metal roofing performance.
Material Comparison
| Material | Lifespan (Renfrew County) | Cost Range (per sq ft) | Snow Shedding | Pros | Cons |
|---|---|---|---|---|---|
| Three-tab asphalt | 12–18 years | $2.50–$3.50 | Poor | Lowest cost, widely available | Short lifespan, poor wind/hail resistance |
| Architectural asphalt | 18–25 years | $3.50–$5.50 | Fair | Best value, good appearance | Ice dam risk without proper ventilation |
| Impact-resistant asphalt | 22–30 years | $5.00–$7.00 | Fair | Hail resistance, insurance discounts | Higher upfront cost |
| Standing seam metal | 40–60 years | $12–$18 | Excellent | Longest lifespan, best snow shedding | Highest cost, specialized installers |
| Exposed fastener metal | 25–35 years | $8–$12 | Good | More affordable metal option | Fastener maintenance, less durable |
The Installation Process
A typical residential roof replacement in Renfrew County follows these steps:
- Deck inspection: After tear-off, the roof deck (plywood or OSB) is inspected for rot, damage, or inadequate nailing. Damaged sections are replaced.
- Underlayment: A synthetic or felt underlayment is installed over the entire deck. In Renfrew County, high-quality synthetic underlayment is recommended for its superior tear resistance and UV stability during installation delays.
- Ice and water shield: Installed at eaves (minimum 900 mm from interior wall line per Ontario Building Code), in all valleys, and around all roof penetrations. Full deck coverage is an option many Renfrew County homeowners choose for maximum protection.
- Drip edge: Metal drip edge is installed along eaves and rakes to direct water away from the fascia and into the gutters.
- Flashing: Step flashing is installed at all roof-wall intersections. Counter flashing is installed around chimneys. Vent pipe flashing boots seal around plumbing vents. Skylight flashing is installed per manufacturer specifications.
- Shingle installation: Shingles are installed from the eave upward, staggered to prevent water channels. Proper nailing pattern and depth is critical for wind resistance.
- Ridge and hip caps: Pre-fabricated ridge cap shingles or ridge vent assemblies are installed at peaks. Ridge vents provide crucial attic exhaust ventilation.
- Clean-up: Magnetic sweep for dropped nails, site cleanup, and debris removal from gutters.
Ontario Building Code Requirements
The Ontario Building Code (O. Reg. 332/12) Part 9, Section 9.26 — Roofing sets out mandatory standards for residential roofs in Renfrew County. Key requirements include:
- Minimum slope: Asphalt shingles require minimum 1:6 roof slope. Metal roofing and other materials have their own minimum slope requirements per manufacturer specifications.
- Ice and water shield: Required at eaves on slopes of 1:3 or steeper, extending a minimum of 900 mm from the interior wall line. Also required in all valleys.
- Ventilation: Attic ventilation ratio of at least 1:300 (vent area to insulated ceiling area), with 50% intake and 50% exhaust. Some municipalities in Renfrew County require 1:150 for roofs with certain configurations.
- Maximum layers: No more than two layers of shingles allowed. The second layer must not exceed the first in weight.
- Underlayment: Minimum 30 lb felt or ASTM-compliant synthetic underlayment required under asphalt shingles.
- Flashing: Must be corrosion-resistant metal installed to direct water onto the roof covering.
Building permits are required in most Renfrew County municipalities for full re-roofing. The permit process typically includes plan review and at least one inspection. See the regulations guide for municipality-specific information.