7 Steps to Install Asphalt Shingles: Why Hiring a Professional Roofer Makes Sense

Installing a new roof is one of the most significant home improvement projects you’ll undertake. Many homeowners face frustrating challenges when attempting to install asphalt shingles themselves – from damaged materials and incorrect installation to water leaks and premature roof failure. These issues don’t just create immediate headaches; they can also lead to expensive repairs down the road.

In this comprehensive guide, we’ll walk you through the seven essential steps to installing asphalt shingles correctly. You’ll learn everything from proper preparation to the final ridge cap installation. We’ll also explain why, despite having this knowledge, hiring a professional roofer might still be your wisest choice for ensuring durability, safety, and warranty protection for your home.

Understanding Asphalt Shingle Roofing Basics

Why Asphalt Shingles Remain Popular

Asphalt shingles continue to dominate the residential roofing market for good reason. They offer an excellent balance of durability, aesthetic appeal, and cost-effectiveness. Before attempting any roofing project, it’s crucial to understand what makes a quality installation.

Properly installing asphalt shingles requires more than basic DIY skills. It demands precision, roofing knowledge, and specialized tools. Understanding the complete installation process helps homeowners make informed decisions about whether to tackle this project themselves or hire professionals.

Essential Tools and Materials

Before starting any roofing installation procedure, you’ll need to gather specific tools and materials:

• Asphalt shingles (plus 10-15% extra for waste)
• Roofing underlayment
• Roofing nails (1¼-inch galvanized)
• Drip edge and flashing materials
• Ridge vent and cap shingles
• Roofing hammer or nail gun
• Utility knife and chalk line
• Ladder and safety equipment (harness, roof brackets)
• Pry bar and roofing cement

The 7-Step Process to Install Asphalt Shingles

Step 1: Prepare Your Roof Deck

The foundation of a successful installation begins with proper preparation:

1. Remove all existing roofing materials (for re-roofs)
2. Inspect the deck for damage, replacing any rotted or damaged wood
3. Ensure the surface is clean, smooth, and dry
4. Check that all nail heads are flush with the deck surface

This critical preparation stage is where many DIY attempts falter. Professional roofers are trained to identify structural problems that might not be obvious to the untrained eye.

Step 2: Install the Underlayment

Understanding what goes under roof shingles is essential for long-term roof performance. The underlayment acts as a secondary moisture barrier. For proper installation:

1. Start at the lowest point of the roof
2. Roll out the roofing underlayment for shingles horizontally
3. Overlap rows by 2-4 inches (more in high-wind areas)
4. Secure with roofing nails approximately 12 inches apart
5. Install ice and water shield in valleys and around roof penetrations

Proper underlayment is your roof’s second line of defense against weather, making it non-negotiable for roof longevity.

Step 3: Install Drip Edge

The drip edge serves multiple important functions:

• Protects fascia boards from water damage
• Directs runoff into gutters
• Prevents water infiltration under the roofing materials

Installation sequence:

1. Install along the eaves first (before underlayment)
2. Secure with roofing nails every 12 inches
3. Install along the rakes after the underlayment
4. Overlap pieces by at least 2 inches in the direction of water flow

Step 4: Apply Starter Shingles

The starter course is a critical component of the roofing installation procedure that’s often overlooked:

1. Install starter strips along the eaves
2. Either use manufactured starter strips or modified regular shingles
3. Position to overhang the eaves by ¼ to ⅜ inch
4. Nail securely 3-4 inches up from the eave edge

This starter course prevents water from seeping between the seams of the first row of regular shingles, providing crucial wind resistance.

Step 5: Install Shingle Courses

Now comes the main part of installing roof shingles:

1. Begin the first full course at the rake edge
2. Follow the manufacturer’s nailing pattern (typically 4-6 nails per shingle)
3. Use chalk lines to ensure straight, even courses
4. Stagger the seams between courses (typically by half a tab)
5. Cut shingles at valleys and around roof penetrations
6. Continue upward toward the ridge

This labor-intensive step requires careful attention to detail. Improper nailing is the number one cause of shingle failure, affecting both leak resistance and warranty coverage.

Step 6: Install Flashing

Proper flashing is essential around:

• Chimneys and skylights
• Vent pipes and exhausts
• Wall intersections
• Valleys

Professional installation includes:

1. Installing base flashing first
2. Integrating with shingles as you progress
3. Applying counter flashing where needed
4. Sealing joints with appropriate roofing cement

Flashing details are often where leaks begin, making this technical step crucial for roof integrity. Learning about what goes under roof shingles, including proper flashing, is essential for a complete understanding of the roofing system.

Step 7: Install Ridge Caps

The final step in installing roof shingles is applying ridge caps:

1. Install ridge vents if specified in your design
2. Use pre-made ridge caps or cut regular shingles into caps
3. Begin at the end opposite the prevailing wind direction
4. Overlap each cap by 5-6 inches
5. Secure with roofing nails (one on each side)
6. Cover nail heads on the final cap with roofing cement

Why DIY Roofing Often Falls Short

Safety Hazards

Roofing consistently ranks among the most dangerous home improvement projects:

• Falls remain the leading cause of construction fatalities
• Working on pitched surfaces requires specialized safety equipment
• Carrying heavy materials up ladders creates fall risks
• Weather conditions can change rapidly, creating slippery surfaces

Professional roofers undergo safety training and use equipment that most homeowners don’t have access to.

Quality and Warranty Concerns

When homeowners tackle installing roof shingles themselves, they often encounter:

1. Voided manufacturer warranties (many require professional installation)
2. Improper nailing patterns that compromise wind resistance
3. Inadequate ventilation calculations
4. Incorrect material choices for specific roof conditions

Did you know that the number of roof shingles in a bundle affects your material calculations? Professional roofers understand these nuances and plan accordingly.

Hidden Costs of DIY Installation

While saving on labor costs is tempting, DIY roofing often leads to unexpected expenses, such as:

• Specialized tools that will rarely be used again
• Material waste from improper cutting (up to 20%)
• Potential structural damage from improper techniques
• Future repair costs for addressing mistakes
• Medical costs from potential injuries

The Professional Advantage

Expert Knowledge and Craftsmanship

Professional roofers bring specialized knowledge to your project:

• Understanding of local building codes and requirements
• Experience with various shingle types, including premium options like OC Duration shingles
• Ability to identify and address underlying issues
• Proper ventilation calculation experience
• Access to contractor-grade materials not available to the public

Efficiency and Warranty Protection

A qualified St Louis roofing contractor like Brandon J Roofing offers:

• Completion of most residential roofs in 1-2 days
• Manufacturer warranties that remain valid with professional installation
• Workmanship warranties for additional protection
• Proper disposal of old materials
• Thorough cleanup after project completion

Superior Results and Peace of Mind

The difference between DIY and professional roof installation is often visible in:

• Straight, uniform shingle lines
• Properly executed details around penetrations
• Correct flashing installation
• Appropriate ventilation integration
• Secure, weather-tight seals and transitions

Professional roofers can also spot and address issues like roofing shingle repair needs that might otherwise go unnoticed.

Install High-Quality Shingles with The Best

While understanding how to install asphalt shingles is valuable for any homeowner, recognizing the complexity involved helps put professional installation in perspective. Brandon J Roofing brings years of experience to every project, ensuring your roof is crafted with precision and expertise that withstands St. Louis’s challenging weather conditions.

From proper material selection to flawless installation techniques, professional roofers provide peace of mind that simply can’t be matched by DIY efforts. When you consider the investment you’re making in your home’s protection, professional installation represents true value rather than an added expense. Ready to see the difference?

GET A ROOF REPLACEMENT