Your roof is one of the most important parts of your home. It keeps out rain, snow, and wind. Most North American homes have asphalt roofs. But what exactly are they? How long do they last? And when should you repair or replace yours? We’ll answer all of these questions.
What Are Asphalt Shingles?
Asphalt shingles are the most popular roof covering in North America. They’re called “composition shingles” because they’re made from multiple materials layered together.
Here’s what’s in an asphalt shingle:
- Base mat: This is the core. Modern shingles use fiberglass. Older shingles used organic mats made from wood fibers.
- Asphalt coating: This waterproof layer keeps water out of your home.
- Granules: Small pebbles on top protect the asphalt from UV rays and give shingles their color.
Think of it like a sandwich: the mat is the bread, asphalt is the filling, and granules are the toppings.
Shingle Types and Styles
Asphalt shingles come in three main styles:
| Shingle Type | What It Looks Like | Cost Level | Best For |
|---|---|---|---|
| 3-Tab Shingles | Flat with three notches per shingle. Simple and uniform. | Budget-friendly | Basic protection, simple roofs |
| Architectural Shingles | Thicker, layered look with more dimension. More upscale appearance. | Mid-range | Homes where curb appeal matters |
| Designer Shingles | Designed to look like cedar, slate, or stone. Premium appearance. | Premium | High-end homes, maximum curb appeal |
The Pros and Cons of Asphalt Roofs
Why Homeowners Love Asphalt Shingles
- Affordable: Asphalt is the least expensive roofing option.
- Widely available: Every roofer in Canada installs them. Repairs are easy to find.
- Many color choices: You can match almost any home style.
- Easy repairs: Single shingles can be replaced without redoing your entire roof.
- Quick installation: Roofers can install asphalt shingles faster than other materials.
Trade-Offs to Consider
- Shorter lifespan: Asphalt roofs don’t last as long as metal, slate, or tile.
- Wind damage: High winds can blow off shingles. You need good fastening.
- Hail damage: Large hail can crack or dent shingles.
- Algae and stains: Black streaks appear over time without cleaning.
- Loses granules: Shingles shed granules as they age, which is normal.
How Long Do Asphalt Roofs Actually Last?
This depends on the quality of the shingles and how well they’re installed and maintained.
| Shingle Type | Typical Lifespan | Warranty | Climate Impact |
|---|---|---|---|
| 3-Tab Shingles | 15-20 years | 20-25 year warranty | Shorter in harsh winters |
| Architectural Shingles | 20-25 years | 25-30 year warranty | Moderate in harsh winters |
| Designer Shingles | 25-30+ years | 30-50 year warranty | Better in harsh winters |
These numbers are for shingles installed correctly with proper ventilation. Canadian winters with freeze-thaw cycles can shorten lifespans. Snow, ice, and UV rays also play a role.
❌ MYTH: A 30-Year Warranty Means Your Roof Lasts 30 Years
Not quite. Warranties are usually prorated. That means the manufacturer pays less over time. By year 10, you might only get 50% coverage. By year 20, you get almost nothing. Always read the fine print.
Cost and Budgeting for Asphalt Roofs
What You’ll Actually Pay
Roofing costs depend on shingle quality, roof complexity, and whether you’re doing a tear-off or overlay.
| Work Type | Budget Range (Per Square)* | What’s Included |
|---|---|---|
| 3-Tab Shingles | $85-$150 | Budget shingles, standard installation |
| Architectural Shingles | $150-$250 | Mid-range shingles, standard installation |
| Designer Shingles | $250-$400+ | Premium shingles, full installation |
*A “square” is 100 square feet of roof. Most homes need 10-30 squares.
Cost Adders (Extra Charges)
Your final bill might be higher if you have:
- Steep or complex roofs: Harder to work on = higher labor costs.
- Tear-off vs. overlay: Removing old shingles costs more than layering new ones on top.
- Deck repairs: Rotted plywood needs replacement before new shingles go on.
- Better underlayment: Ice and water shield protects valleys and eaves.
- New flashing: Chimneys, skylights, and walls need proper flashing.
- Ventilation work: Adding or fixing ridge and soffit vents.
- Disposal fees: Dumping old shingles costs money.
Sample Cost Breakdown for a 2,000 sq ft Home
| Item | Percentage of Total | Est. Amount |
|---|---|---|
| Shingles | 40% | $4,000 |
| Labor | 35% | $3,500 |
| Underlayment & Flashing | 15% | $1,500 |
| Disposal & Misc | 10% | $1,000 |
| TOTAL | 100% | $10,000 |
What Goes Into an Asphalt Roof?
The Layers (From Bottom to Top)
A properly installed asphalt roof isn’t just shingles. There’s a whole system underneath:
- Roof decking: The plywood or OSB board that holds everything.
- Underlayment: A waterproof barrier under the shingles.
- Ice and water shield: Extra protection in valleys and along eaves.
- Drip edge: Metal trim that directs water away from fascia.
- Shingles: The visible layer you see.
- Ridge caps: Shingles on the roof peak.
- Flashing: Metal pieces around chimneys, vents, and walls.
Each layer has a job. Skip one, and you’re risking leaks.
Flashing: The Often-Forgotten Hero
Flashing is metal installed around any roof penetration. This includes chimneys, skylights, plumbing vents, and walls. Without proper flashing, water finds its way inside.
Common flashing types:
- Step flashing: Where a roof meets a wall.
- Valley flashing: Where two roof slopes meet.
- Chimney flashing: Around chimneys.
- Skylight flashing: Around skylights.
- Pipe boots: Around plumbing vents.
❌ MYTH: You Can Seal Flashing With Roof Cement and It Lasts Forever
Roof cement is temporary. It cracks, shrinks, and fails. Proper flashing should be metal, not sealed with goop. Save the cement for small gaps only.
Installation Matters More Than You Think
The best shingles installed poorly will fail early. Here’s why installation quality makes a huge difference:
Key Installation Details
- Nail placement: Nails must hit the nailing line precisely. Too high or too low and shingles blow off in wind.
- Nail count: Each shingle needs 4-6 nails (depending on brand). Roofers who use fewer nails cut corners.
- Substrate prep: The deck must be clean and secure before shingles go on.
- Valley method: The way valleys are constructed (open vs. closed) affects water flow.
- Weather conditions: Shingles can’t be installed below 50°F. Cold makes them brittle.
Ventilation and Your Attic Health
Good roof ventilation is boring—until you don’t have it. Then you get problems.
Your attic needs air to flow in and out. This keeps moisture away and prevents heat buildup in summer.
How Attic Ventilation Works
- Soffit vents: Let air in (intake) along the bottom of your roof.
- Ridge vents: Let air out (exhaust) at the top.
- Gable vents: Extra exhaust in gable-style homes.
- Baffles: Keep soffit vents from getting blocked by insulation.
You need balanced intake and exhaust. If you have lots of intake but no exhaust, air stagnates and moisture builds up.
❌ MYTH: More Vents Are Always Better
Wrong. You need balance. Too many vents without enough intake (or vice versa) creates negative air pressure. This can actually suck moisture into your attic. Aim for 1 square foot of vent per 150 square feet of attic space.
Ice Dams and Winter Roof Problems
Canadian winters are tough on roofs. Ice dams are one of the biggest winter headaches.
How Ice Dams Form
- Heat escapes from your home through the roof.
- This melts snow on the roof, even when it’s cold outside.
- Water runs down to the cold eaves and refreezes.
- Ice builds up and dams, trapping more water behind it.
- Water backs up under the shingles and leaks inside.
How to Prevent Ice Dams
- Improve attic insulation: Less heat = less melt.
- Better ventilation: Keeps roof temperature consistent.
- Clear gutters: So water can flow freely.
- Ice and water shield: Protects eaves even if backup happens.
- Safe snow removal: Push snow off eaves (don’t damage the roof).
Heat cables work in some cases, but they’re expensive and only a temporary fix. Fix the real problem instead.
Common Asphalt Roof Problems and Solutions
| Problem | What Causes It | Fix | Can DIY? |
|---|---|---|---|
| Black streaks/algae | Algae and mold growth | Soft wash cleaning (not high pressure) | Yes, with care |
| Lifted shingles | Seal strip failed or high winds | Re-seal or replace shingles | Maybe, one or two |
| Blown-off shingles | High winds, poor installation | Replace shingles | No |
| Nail pops | Deck movement, improper nailing | Replace nails and seal | No |
| Leaks at valleys | Flashing failure or debris | Re-flash or replace valley | No |
| Curling shingles | Age, UV exposure | Replace roof | No |
Cleaning and Maintenance
How to Clean Black Streaks Safely
- Use low pressure: High-pressure washers damage shingles. Use a soft wash or garden hose with low pressure.
- Use the right cleaner: Bleach or specialized roof cleaners work, but follow directions.
- Don’t scrub: Let the cleaner do the work. Scrubbing removes granules.
- Rinse well: Make sure all cleaner is gone.
❌ MYTH: Cleaning Your Roof Is Cheap and Easy
It looks easy but isn’t. If you pressure wash too hard, you’ll damage granules and void your warranty. If you scrub, you’ll do the same. Hire professionals. It’s worth it.
Regular Maintenance Tasks
- Clear gutters twice a year: Spring and fall.
- Trim branches: Keep trees 6+ feet away from roof.
- Inspect after storms: Look for missing or damaged shingles.
- Check flashing: Make sure it’s sealed and not rusted.
- Look for granule loss: Some is normal. Lots is a problem.
Choosing the Right Roofer
Installation quality matters more than shingle price. Here’s how to find a good roofer:
What to Look For
- Proper licensing and insurance: This protects you if something goes wrong.
- Local references: Call past customers and ask about their experience.
- Detailed written estimate: Know exactly what’s included (tear-off? New flashing? Underlayment spec?)
- Manufacturer certification: GAF, CertainTeed, and others have certified installers.
- Warranty on workmanship: Not just the product warranty.
- Permit and inspection plan: They should pull permits. If they won’t, walk away.
Red Flags (Walk Away)
- No permit or inspection required
- Vague estimate (“roof replacement” with no details)
- Cash-only payment
- “We don’t need to fix the flashing”
- Pressure to decide immediately
- Unclear warranty terms
Before Your Roof Gets Installed
Here’s your homeowner checklist:
- Get 2-3 detailed estimates
- Know how many layers your current roof has
- Take photos of current deck condition
- Confirm tear-off vs. overlay in writing
- Ask about flashing replacement details
- Confirm underlayment specification
- Understand the warranty (product AND workmanship)
- Get a timeline in writing
Common Questions Homeowners Ask
How long do asphalt roofs last in Canada?
Typically 15-25 years depending on the shingle tier and weather. Canadian winters shorten lifespans because freeze-thaw cycles are tough on shingles.
Can asphalt shingles be painted or coated?
Technically yes, but it’s not recommended. Coatings can trap moisture and void warranties. If you want a different color, replace the shingles.
Can I add a second layer of shingles over my existing roof?
Maybe. Check your local codes. Ontario allows one layer over existing shingles in most cases. But tear-off is usually better because it lets roofers inspect and repair the deck.
What’s the difference between felt and synthetic underlayment?
Felt is the old standard. Synthetic is newer and lasts longer (won’t tear as easily). Synthetic costs more but is worth it.
How do I know if my roof needs replacing?
Replace if you see: multiple missing shingles, significant curling, large areas of granule loss, leaks, or shingles older than 20 years. When in doubt, get an inspection.
Final Thoughts
Your roof protects everything you care about. Asphalt shingles are affordable and reliable when installed correctly and maintained well.
Don’t skip on underlayment or flashing just to save money. Don’t hire a roofer based on price alone. And don’t ignore signs of damage.
Your roof is an investment in your home. Treat it that way.
Have questions about your roof? Our roofing experts are here to help. Whether you need a repair, replacement, or just answers, we’re a phone call away.
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