How to install asphalt shingles

Asphalt shingles are a highly popular roofing choice among consumers, valued not only for their aesthetics but also for their durability and affordability.

However, their installation is a delicate operation that requires skill and precision. If you lack experience in roofing installation, you might fall into one of the many pitfalls that amateur roofers often encounter.

To help you succeed, our roofers have put together valuable advice to guide you through the process. Discover our step-by-step guide below!

How to Install Asphalt Shingles?

Installing asphalt shingles is a crucial step in creating a durable and visually appealing roof. In this guide, our roofers in Laval walk you through the preparatory steps and the detailed process of shingle installation.

Step 1: Gather the Necessary Materials and Tools

First, assemble all the materials required for your chosen asphalt shingles installation:

Materials:

• Asphalt shingles
• Galvanized roofing nails (typically 1-1/4″ is sufficient)
• Asphalt plastic cement
• Eave protection (self-adhesive protective membrane)
• Synthetic underlayment
• Flashing and valley liners
• Attic vents

Tools:

To ensure a smooth and efficient installation, you should also have the appropriate tools:

• Shingle removal shovel (to remove old shingles)
• Tin snips (for cutting metal flashing)
• Chalk line
• Hook blade utility knife
• Roofing square
• Roofing hammer and/or pneumatic nail gun
• Air compressor for pneumatic tools
• Caulking gun
• Measuring tape
• Trowel
• Pry bar
• Personal protective equipment, including a harness, rope, lanyard, energy absorber, anchor, safety glasses, steel-toe boots

Step 2: Roof Preparation

Before starting the installation, properly prepare the roof surface:

• Remove the old roofing material if necessary.
• Inspect the wooden decking and replace any damaged sections.
• Install an eave protection membrane and synthetic underlayment to optimize waterproofing.
• Place flashing and valley liners to protect sensitive areas from water infiltration.

Step 3: Installing the Asphalt Shingles

Progressing from the Base to the Ridge

Shingle installation always begins at the base of the roof and progresses upward to the ridge. This ensures uniform coverage and proper water drainage, preventing leaks.

Marking Reference Lines

Before securing the first shingles, use a chalk line to create reference marks. This helps maintain straight lines and ensures precise alignment across the entire roof. Proper alignment reduces irregularities that could compromise the roof’s waterproofing and appearance.

Installing the First Reversed Row

The installation begins with a reversed row of shingles (cutting off the tabs). This technique creates a watertight base, serving as a solid foundation for subsequent rows. Skipping this step could allow water to seep through the gaps between the shingles, weakening the structure.

Securing with Galvanized Nails

Shingles should be fastened using 1-1/4” galvanized nails, which provide excellent corrosion resistance and ensure a strong hold. Each shingle should be secured with 4 to 6 nails, depending on wind exposure. Too few nails can cause shingles to lift in strong winds, while excessive nailing can reduce flexibility and hinder the roof’s ability to adapt to movements.

Overlapping Shingles Properly

Ensure that each shingle overlaps the previous one correctly. This prevents water and wind from penetrating beneath the roofing material. Proper overlapping enhances waterproofing and increases the lifespan of your roof.

Step 4: Sealing and Waterproofing

Next, properly seal every joint and gap using asphalt plastic cement. This step ensures the waterproofing of critical roofing components such as the chimney, vents, roof fans, and ridge caps.

Before applying sealant, consider the water drainage direction to ensure unobstructed water flow.

Step 5: Cleanup and Finishing Touches

A meticulous installation requires precise finishing touches, including trimming excess shingles and applying sealants where necessary.

Shingle Installation Techniques Based on Shingle Type

Different installation techniques apply to various types of asphalt shingles, each suited to specific climate conditions and roofing styles.

1. Step Installation (Ladder Pattern)

This method is primarily used for 3-tab shingles, where each row is installed in a linear pattern from the bottom up. This technique creates a traditional aesthetic and is suitable for moderately sloped roofs.

However, it is less effective against strong winds since the vertical seams are aligned, increasing the risk of water infiltration if waterproofing is inadequate.

2. Staggered Installation (Stair-Step Pattern)

This technique is ideal for architectural shingles, where each row is offset by half a shingle width from the previous row. The staggered pattern enhances wind resistance, as the seams do not align.

By optimizing overlap, this technique provides better waterproofing and greater durability in harsh weather conditions. It is frequently used in areas prone to high winds and storms.

3. Diagonal Installation

This method ensures precise alignment and prevents positioning errors. The shingles are installed along a slanted guideline, distributing weight evenly and reducing the risk of wind uplift.

Diagonal installation is particularly suitable for large roofing surfaces and steep slopes. It also creates a modern and dynamic visual effect.

How to Cut Asphalt Shingles?

When cutting asphalt shingles, there are two common methods:

Using a Utility Knife

A utility knife with a hook blade is a precise tool for cutting asphalt shingles. Follow these steps:

• Ensure the blade is sharp. A dull blade makes cutting difficult and imprecise.
• Measure and mark the shingle with a measuring tape.
• Place the shingle on a stable surface.
• Hold the knife securely and keep fingers away from the blade.
• Apply firm, consistent pressure while cutting along the marked line.
• Repeat the process for each shingle, ensuring straight, clean cuts.

Using a Pneumatic Cutter

A pneumatic cutter can speed up the cutting process, especially for large projects.

• Use a pneumatic cutter connected to an air supply and ensure the blade is in good condition.
• Mark the shingle with a measuring tape and chalk.
• Secure the shingle on a solid surface to minimize vibrations.
• Align the cutter blade with the marked line.
• Press the trigger and smoothly cut along the line.
• Keep hands and fingers away from the blade for safety.

Safety Reminder: Regardless of the cutting method, always wear safety glasses and gloves to prevent injuries.Always remember to work safely.

Safety First: Secure Installation PracticesAlways prioritize safety when working on a roofing project.

Installing asphalt shingles or performing any roofing work requires strict adherence to building codes and occupational health and safety regulations.

Couvreurs Duro-Toit can install your asphalt shingles

Don’t underestimate the complexity of installing asphalt shingles on a pitched roof. This work is best left to professional roofers if you do not feel completely comfortable with any of the steps outlined above.

When you rely on Duro-Toit, you benefit from personalized service, expert advice and superior workmanship. We’re dedicated to customer satisfaction and we’ll build a roof that meets your needs and adds value to your property.

If you would like more information on our asphalt shingle installation service or to learn more about our other roofing products and services, contact us today!