Below are answers to the questions Renfrew County homeowners most often ask about roofing — from how long asphalt shingles last in Ontario's climate, to permit requirements, ice dam prevention, and how to evaluate contractor warranties. For pricing, see our roofing cost guide. For material comparisons, see our roofing materials guide.
How often should I replace my roof in Ontario?
Asphalt shingles — the most common residential material in Ontario — typically last 20–25 years. In Renfrew County's climate, repeated freeze-thaw cycles and heavy snow loads can reduce that lifespan, particularly for lower-quality 3-tab shingles. Watch for these end-of-life signs:
- Granule loss — granules accumulating in gutters or visible baldness on shingles
- Cupping or curling at shingle edges
- Cracking or brittleness, especially visible from the ground on a warm day
- Moss or lichen growth (holds moisture, accelerates decay)
- Multiple areas of flashing failure around chimney or vents
If your roof is approaching 20 years and showing two or more of these signs, budget for replacement within 2–3 years. Waiting until active leaks develop is almost always more expensive — water intrusion into the decking or attic insulation adds remediation costs.
Do I need a permit to replace my roof in Renfrew County?
Yes — most Renfrew County municipalities require a building permit for a complete roof replacement. This includes the Town of Renfrew, City of Pembroke, Petawawa, and the surrounding townships. Minor repairs — patching a few shingles, replacing flashing on a chimney — typically don't require permits.
Important: your contractor should pull the permit, not you. A contractor who suggests you pull the permit as "owner-builder" is typically trying to avoid the associated inspection. The permit triggers a building inspection that confirms ice and water shield placement, ventilation compliance, and deck condition — all of which protect you. See our building permits guide for municipality contacts and application details.
What causes ice dams and how do I prevent them?
Ice dams are a frequent Renfrew County problem. Here's the mechanism:
- Heat escapes from the living space through an under-insulated attic
- The underside of the roof deck warms, melting snow on the upper roof slope
- Meltwater flows down to the eave overhang, which is exposed to outside air temperature
- Water refreezes at the cold eave, building up an ice dam
- The ice forces water back up under the shingles, where it penetrates the roof deck
Prevention addresses the cause, not the symptom:
- Adequate attic insulation (R-49 minimum in Renfrew County) keeps the roof deck cold and at uniform temperature
- Balanced soffit-to-ridge ventilation flushes warm air before it warms the deck
- Ice and water shield at eaves catches water that does back up — but it doesn't stop the dam from forming
If you have recurring ice dams, the roof replacement is an opportunity to improve the underlying conditions — address the attic insulation and ventilation at the same time.
Metal vs asphalt for Renfrew County — which should I choose?
Both are sound choices; the right answer depends on your budget and how long you plan to stay in the home.
| Architectural Asphalt | Metal (Steel/Aluminum) | |
|---|---|---|
| Upfront cost (typical home) | $10,000 – $16,000 | $15,000 – $28,000 |
| Expected lifespan | 22–30 years | 40–60 years |
| Snow shedding | Moderate — can accumulate | Excellent — sheds naturally |
| Ice dam risk | Higher with poor insulation | Lower due to snow shedding |
| Noise (rain/hail) | Quiet | Louder (mitigated by insulation) |
For rural Renfrew County properties — especially those with heavy snow loads, significant tree cover, and a long ownership horizon — metal is frequently the better lifetime investment. For homeowners on a tighter budget or with shorter-term plans, quality architectural shingles remain a proven and cost-effective solution.
Can I put new shingles over old ones?
The Ontario Building Code allows a maximum of two shingle layers on a residential roof. If your home already has two layers — common in older Renfrew County homes — a full tear-off to the deck is required before re-roofing.
Even within the two-layer allowance, overlaying has meaningful downsides:
- Hidden deck problems: Moisture damage, rot, or sagging in the deck won't be discovered until the next tear-off — by which time it may have worsened significantly
- Uneven base: Existing shingle bumps and ridges telegraph through the new layer, affecting appearance and potentially shingle adhesion
- Added weight: Two shingle layers add approximately 3–5 lbs per sq ft of additional load on the structure
- Warranty considerations: Some manufacturers will not honour product warranties for shingles installed as an overlay
Many experienced Renfrew County roofers recommend a full tear-off even when a second layer is technically permitted, for the reasons above.
What is ice and water shield?
Ice and water shield is a self-adhering waterproofing membrane installed directly on the roof deck before shingles go on. Unlike standard roofing felt (which is a non-adhering underlayment), ice and water shield seals itself around nails and staples — creating a continuous waterproof layer that resists water infiltration even if shingles are damaged or lifted.
The Ontario Building Code requires ice and water shield at all eaves, extending a minimum of 900 mm from the interior wall line inward. It is also required at valleys. Given Renfrew County's ice dam history, many local contractors apply extended coverage — full eave overhang, all valleys, around all penetrations (chimney, pipe vents, skylights).
Ice and water shield is your last line of defence against water that backs up under shingles. It's not a substitute for proper attic insulation and ventilation, which prevent ice dams from forming in the first place — but it provides critical protection when ice dams do occur.
What warranty should I expect from a roofing contractor?
Roofing comes with two separate warranties — understand both before signing:
- Manufacturer's product warranty (30–50 years): Covers defects in the shingle material itself. Premium architectural shingle lines carry "lifetime" limited warranties. This warranty is only valid when the product is installed per the manufacturer's specifications — incorrect nailing patterns or improper underlayment can void it even if a material defect occurs.
- Contractor's workmanship warranty (typically 2–10 years): Covers installation errors — improperly installed flashing, missing or insufficient ice and water shield, incorrect valley treatment, poor chimney work. This is the more practically important warranty in the first decade of a new roof.
Get both in writing before any deposit is paid. A one-year workmanship warranty from a roofing contractor is below market standard for Renfrew County — aim for a minimum of 5 years workmanship. The contractor's willingness to back their work for a meaningful period is a reliable signal of their confidence in the installation.
How much does roofing cost in Renfrew County?
Roofing costs for a typical 1,200–1,500 sq ft Renfrew County home (all prices before HST):
- Asphalt 3-tab shingles: $8,000 – $12,000
- Architectural (laminate) asphalt shingles: $10,000 – $16,000
- Metal roofing (steel or aluminum): $15,000 – $28,000
- Cedar shake: $18,000 – $35,000
Additional costs to budget for: building permit ($150–$600), fascia and soffit repair ($20–$40/linear ft), eavestrough replacement ($15–$30/linear ft). See our full roofing cost guide for a detailed breakdown of all cost factors including pitch, tear-off layers, deck repair, and HST rebate information.