Laying Asphalt Shingles

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Laying Asphalt Shingles – Asphalt shingles are one of the most popular roofing materials used across North America and many other parts of the world. They are durable, affordable, relatively easy to install, and come in a wide variety of styles and colors. For homeowners or contractors looking to protect a property with a roof that combines longevity and style, asphalt shingles are a go-to choice.

This article provides a comprehensive step-by-step guide to laying asphalt shingles, including preparation, installation, and maintenance tips, ensuring a strong and weather-resistant roof that lasts for decades.

Why Choose Asphalt Shingles?

Before diving into the installation process, it is worth understanding why asphalt shingles are so widely used:

  • Affordability: Asphalt shingles cost significantly less than alternatives like slate, clay tile, or metal roofing.

  • Ease of Installation: Even DIY enthusiasts with some construction knowledge can install them, although professional installation is recommended for longevity.

  • Variety: They are available in three-tab, dimensional (architectural), and luxury designs.

  • Durability: With proper installation, asphalt shingles can last 20–30 years, sometimes longer.

  • Weather Resistance: They are designed to withstand wind, rain, and, depending on the type, even hail and fire.

Tools and Materials Needed

To lay asphalt shingles effectively, having the right tools and materials is essential:

Tools:

  • Hammer or roofing nail gun

  • Utility knife or roofing blade

  • Chalk line

  • Tape measure

  • Pry bar (for removing old shingles)

  • Roofing shovel or spade

  • Ladder and safety harness

  • Caulking gun

Materials:

  • Asphalt shingles (three-tab or architectural)

  • Roofing nails (galvanized, corrosion-resistant)

  • Roofing felt or synthetic underlayment

  • Starter strip shingles

  • Drip edge (metal flashing along roof edges)

  • Ridge cap shingles

  • Roofing cement or sealant

  • Ice and water shield (for colder climates)

Preparation Before Laying Asphalt Shingles

Preparation is one of the most critical phases of any roofing project.

  1. Inspect the Roof Deck
    Remove old shingles, nails, and underlayment. Inspect the plywood decking for rot or damage. Any weak or soft areas must be replaced to provide a solid foundation for the new shingles.

  2. Install Drip Edge
    Drip edge flashing is placed along the eaves of the roof before underlayment. It directs water away from the fascia and into gutters, preventing water damage.

  3. Apply Underlayment
    Roofing felt or synthetic underlayment creates a water-resistant barrier between shingles and decking. Overlap each course by at least 2 inches and secure it with cap nails or staples.

  4. Add Ice and Water Shield (if needed)
    In cold climates where ice dams are common, apply ice and water shield around valleys, chimneys, and eaves. This provides additional protection against water infiltration.

  5. Safety Setup
    Roofing is dangerous work. Ensure proper ladders, harnesses, and fall-protection equipment are in place before beginning.

Step-by-Step Process for Laying Asphalt Shingles

Install Starter Strip Shingles

Starter strips are critical for preventing wind uplift along the roof’s edges. These can be pre-manufactured strips or cut from regular shingles by trimming off the tabs. Place them along the eaves with adhesive edge facing down, then nail them into place.

Begin the First Course

Lay the first row of shingles directly above the starter strip. Align the bottom edge with the eave and secure with four to six nails (depending on wind zone). Drive nails just below the adhesive strip but avoid overdriving, as it can damage the shingles.

Continue Shingle Courses

  • Each subsequent row should overlap the one below by about 5–6 inches, depending on the manufacturer’s specifications.

  • Use a chalk line to maintain straight rows across the roof.

  • Stagger shingle joints to avoid creating straight vertical seams, which can allow water infiltration.

Valleys Installation

Roof valleys, where two roof slopes meet, are prone to leaks. There are two common methods:

  • Open Valley: Metal flashing is exposed, with shingles cut and sealed along the valley edge.

  • Closed Valley: Shingles are woven or cut to cover the valley. This method provides a uniform appearance but must be sealed properly.

Around Roof Penetrations

Chimneys, vents, and skylights require special attention. Install flashing around these features to prevent water leaks. Step flashing should be layered with shingles to ensure water runs over, not under, the flashing.

Ridge Cap Installation

At the roof’s peak, ridge cap shingles are installed to cover the joint where two slopes meet. These shingles are typically pre-cut or cut from standard shingles. Nail them in place and apply roofing cement as extra protection against wind.

Common Mistakes to Avoid

  • Improper Nailing: Nails driven too deep, too shallow, or at an angle can cause shingle blow-off.

  • Skipping Starter Strips: This can leave roof edges vulnerable to wind and water damage.

  • Ignoring Ventilation: Poor attic ventilation leads to heat buildup and moisture, shortening shingle life.

  • Not Sealing Valleys Properly: Valleys are the most leak-prone areas, and poor flashing or sealing can cause significant water damage.

Costs of Laying Asphalt Shingles

The cost depends on the type of shingle and whether you hire a professional or DIY.

  • Material Costs: $90–$150 per roofing square (100 sq. ft.) for three-tab shingles; $150–$250 for architectural shingles.

  • Labor Costs: Professional installation typically adds $2.50–$5.00 per square foot.

  • Total Average: $5,000–$12,000 for an average home roof replacement.

DIY installation can save labor costs but requires proper tools, safety equipment, and experience.

Maintenance After Installation

Even after a successful installation, ongoing maintenance ensures asphalt shingles last their full lifespan.

  • Inspect Annually: Look for curled, missing, or cracked shingles.

  • Clean Gutters: Prevent water backup that can damage shingles and roof decking.

  • Remove Debris: Keep branches, leaves, and dirt off the roof.

  • Address Damage Quickly: Replace missing or damaged shingles immediately to prevent leaks.

  • Check Flashing: Ensure flashing around chimneys and vents remains secure.

Advantages and Disadvantages of Laying Asphalt Shingles

Advantages:

  • Cost-effective

  • Easy to install and repair

  • Available in many styles and colors

  • Suitable for a variety of climates

Disadvantages:

  • Shorter lifespan compared to metal or tile (20–30 years)

  • Vulnerable to high winds and hail

  • Not environmentally friendly, as shingles are petroleum-based

Final Thoughts

Laying asphalt shingles is a practical roofing solution for most homeowners. With proper preparation, installation, and maintenance, asphalt shingles provide decades of reliable protection against the elements. Whether you are considering a DIY project or hiring professionals, following best practices ensures your roof remains both functional and visually appealing.

By investing the time and effort to lay shingles correctly, you safeguard your home’s structural integrity and improve curb appeal, making it one of the most valuable projects in residential construction.