Applying Asphalt Shingles

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Applying Asphalt Shingles



Applying Asphalt Shingles: A Comprehensive Guide

Introduction to Asphalt Shingles

Asphalt shingles are the most popular roofing material in North America, and for good reason. They’re relatively inexpensive, durable, and come in a wide variety of colors and styles. This guide will walk you through the entire process of applying asphalt shingles, from preparing your roof deck to installing the final ridge cap. Whether you’re a seasoned DIYer or a complete beginner, this article will provide you with the knowledge and confidence you need to tackle this important home improvement project.

Before we dive into the specifics, it’s important to understand that roofing can be dangerous. Working at heights always carries a risk of falls, and the tools and materials involved can also pose hazards. Always prioritize safety and take the necessary precautions. If you’re not comfortable working on a roof, it’s best to hire a professional roofing contractor.

This guide assumes a standard residential roof with a typical slope. Complex roof designs may require different techniques and more specialized knowledge. If you have a particularly challenging roof, consult with a professional before starting the project.

Planning and Preparation

Proper planning is crucial for a successful shingle installation. This stage involves assessing your roof, gathering the necessary materials and tools, and preparing the roof deck for the new shingles.

Assessing Your Roof

The first step is to thoroughly inspect your existing roof. Look for signs of damage, such as missing, cracked, or curled shingles. Check for leaks in the attic and around chimneys, vents, and skylights. Pay close attention to areas where water tends to accumulate, such as valleys and around protrusions.

Determining the roof’s square footage is essential for ordering the correct amount of shingles. To calculate the square footage, measure the length and width of each roof plane and multiply the two measurements. Add the square footage of all the planes together to get the total roof area. Remember to add extra for waste (typically 10-15%). Roofing materials are typically sold in “squares,” where one square equals 100 square feet of coverage.

Also, evaluate the condition of the roof deck. The roof deck is the structural layer beneath the shingles, typically made of plywood or OSB (oriented strand board). Check for signs of rot, water damage, or warping. Any damaged sections of the roof deck must be replaced before installing new shingles. Weak or damaged decking will compromise the integrity of the entire roof system.

Gathering Materials and Tools

Here’s a list of the essential materials you’ll need:

  • Asphalt shingles (sufficient quantity for your roof area, plus extra for waste)
  • Underlayment (typically roofing felt or synthetic underlayment)
  • Drip edge (metal flashing installed along the eaves and rakes)
  • Roofing nails (specifically designed for asphalt shingles)
  • Caulk (for sealing around penetrations)
  • Ice and water shield (for areas prone to ice damming, such as eaves and valleys – recommended in colder climates)
  • Ridge cap shingles (for covering the ridge of the roof)
  • Ventilation (ridge vents, soffit vents, or other ventilation systems)

And here’s a list of the tools you’ll need:

  • Hammer or roofing nailer
  • Utility knife
  • Tape measure
  • Chalk line
  • Roofing shovel or pry bar (for removing old shingles)
  • Ladder
  • Safety harness and rope
  • Gloves
  • Safety glasses
  • Dust mask
  • Tin snips (for cutting flashing)

Choosing the right type of asphalt shingles is important. There are two main types: 3-tab shingles and architectural (or dimensional) shingles. 3-tab shingles are the most basic and economical option. Architectural shingles are thicker, heavier, and have a more textured appearance. They also tend to last longer and provide better wind resistance. Consider your budget and the aesthetic you’re trying to achieve when making your choice.

Preparing the Roof Deck

Before you can start installing the new shingles, you need to prepare the roof deck. This involves removing the old shingles, inspecting the deck, and making any necessary repairs.

Start by removing the old shingles using a roofing shovel or pry bar. Work carefully to avoid damaging the roof deck. Be sure to remove all nails and debris from the deck. This is a messy job, so be prepared for a lot of dust and shingle fragments. Wear a dust mask and safety glasses to protect yourself.

Once the old shingles are removed, inspect the roof deck thoroughly. Look for any signs of rot, water damage, or warping. Probe any suspicious areas with a screwdriver or other tool to check for soft spots. Replace any damaged sections of the roof deck with new plywood or OSB of the same thickness. Ensure the new decking is securely fastened to the rafters or trusses.

After repairing the roof deck, sweep or blow off any remaining debris. A clean, smooth surface is essential for proper shingle adhesion. Make sure all nail heads are flush with the surface of the deck. Drive in any protruding nails with a hammer.

Installing Underlayment and Drip Edge

With the roof deck prepared, the next step is to install the underlayment and drip edge. These materials provide an extra layer of protection against water damage and help to ensure the longevity of your roof.

Installing Drip Edge

Drip edge is a metal flashing that is installed along the eaves (the bottom edge of the roof) and rakes (the sloping sides of the roof). It helps to direct water away from the fascia and roof deck, preventing water damage and rot.

Start by installing the drip edge along the eaves. Overlap each piece of drip edge by a few inches. Fasten the drip edge to the roof deck with roofing nails, spaced about 12 inches apart. Make sure the drip edge extends slightly beyond the edge of the roof.

Next, install the drip edge along the rakes. The drip edge on the rakes should overlap the drip edge on the eaves. This ensures that water flows down and away from the roof properly. Again, fasten the drip edge to the roof deck with roofing nails, spaced about 12 inches apart.

When cutting the drip edge, use tin snips. Be careful to avoid sharp edges. Wear gloves to protect your hands.

Installing Underlayment

Underlayment is a water-resistant barrier that is installed over the roof deck. It provides an extra layer of protection against leaks and helps to prevent moisture from damaging the roof deck. The two most common types of underlayment are roofing felt and synthetic underlayment.

Roofing felt is a traditional underlayment material made from asphalt-saturated paper. It’s relatively inexpensive but not as durable as synthetic underlayment. Synthetic underlayment is made from woven polymers and is more resistant to tearing and water damage. It’s also lighter and easier to work with than roofing felt.

Start by rolling out a layer of underlayment along the eaves, overlapping the drip edge. Overlap each subsequent course of underlayment by at least 2 inches. Fasten the underlayment to the roof deck with roofing nails or staples, spaced about 12 inches apart. Work your way up the roof, overlapping each course of underlayment until the entire roof deck is covered.

On roofs with a low slope (less than 4:12), it’s recommended to use a double layer of underlayment for added protection. In areas prone to ice damming, such as eaves and valleys, consider using an ice and water shield instead of underlayment. Ice and water shield is a self-adhering membrane that provides a waterproof barrier against ice and water intrusion.

When installing underlayment around penetrations, such as chimneys, vents, and skylights, cut the underlayment to fit snugly around the penetration. Seal the edges of the underlayment with caulk to prevent water from entering.

Installing Asphalt Shingles

Now that the roof deck is prepared and the underlayment is installed, you can start installing the asphalt shingles. This is the most time-consuming part of the project, but it’s also the most rewarding.

Laying the Starter Course

The starter course is the first row of shingles that is installed along the eaves. It provides a solid base for the rest of the shingles and helps to prevent water from entering under the shingles.

Most manufacturers recommend using a special starter strip shingle, which is a solid strip of asphalt with an adhesive strip along one edge. If you don’t have starter strip shingles, you can create your own by cutting off the tabs from a regular shingle.

Install the starter course along the eaves, with the adhesive strip facing down. The starter course should overhang the drip edge by about 1/2 inch. Fasten the starter course to the roof deck with roofing nails, spaced about 12 inches apart.

Installing the First Course

The first course of shingles is installed directly above the starter course. This course is critical for ensuring proper alignment and spacing of the subsequent courses.

Start by aligning the bottom edge of the first shingle with the top edge of the starter course. Make sure the shingle is flush with the edge of the roof. Fasten the shingle to the roof deck with roofing nails. The number of nails required per shingle varies depending on the manufacturer’s instructions and local building codes. Typically, four to six nails are required per shingle.

Continue installing shingles along the first course, overlapping each shingle by the specified amount. The overlap is typically 5 inches for 3-tab shingles and varies for architectural shingles. Ensure each shingle is properly aligned and securely fastened with roofing nails.

Installing Subsequent Courses

After installing the first course, continue installing subsequent courses, working your way up the roof. Each course should be aligned and overlapped according to the manufacturer’s instructions.

A critical aspect of shingle installation is maintaining proper alignment. Use a chalk line to mark the location of each course. This will help you to ensure that the shingles are installed straight and evenly. Check the alignment frequently to catch any errors early on.

Stagger the joints between the shingles in each course. This helps to prevent water from entering through the seams. The recommended stagger is typically 6 inches for 3-tab shingles and varies for architectural shingles. Follow the manufacturer’s instructions for the specific type of shingles you are using.

When installing shingles around penetrations, such as chimneys, vents, and skylights, cut the shingles to fit snugly around the penetration. Use caulk to seal the edges of the shingles to prevent water from entering.

Pay close attention to valleys. Valleys are the areas where two roof planes meet. They are particularly vulnerable to leaks. There are two main types of valley treatments: open valleys and closed valleys.

Open valleys have a wide strip of metal flashing exposed. This allows water to flow freely down the valley. Closed valleys have the shingles extending across the valley, creating a seamless appearance. Open valleys are generally considered to be more effective at preventing leaks, but closed valleys are more aesthetically pleasing.

Fastening Shingles Correctly

Proper nail placement is essential for ensuring that the shingles are securely fastened to the roof deck. The nails should be driven straight and flush with the surface of the shingle. Overdriving the nails can damage the shingle and reduce its wind resistance. Underdriving the nails can allow the shingle to lift up in high winds.

The manufacturer’s instructions will specify the exact location where the nails should be placed. In general, the nails should be placed just below the sealant strip on the shingle. Use the correct type of roofing nails. These nails have a large head and a barbed shank that helps to prevent them from pulling out.

If you are using a roofing nailer, adjust the pressure so that the nails are driven to the correct depth. Practice on a scrap piece of shingle to get a feel for the correct pressure.

Installing Ridge Cap Shingles

The ridge cap shingles are the final row of shingles that are installed along the ridge of the roof. They provide a finished look to the roof and help to protect the ridge from water damage.

Ridge cap shingles are typically pre-cut to the correct size and shape. You can also create your own ridge cap shingles by cutting regular shingles into thirds.

Start by installing the ridge cap shingles at one end of the ridge, overlapping each shingle by about 5 inches. Fasten the ridge cap shingles to the roof deck with roofing nails. The number of nails required per shingle will vary depending on the manufacturer’s instructions.

Work your way along the ridge, overlapping each shingle until the entire ridge is covered. Make sure the ridge cap shingles are properly aligned and securely fastened.

At the end of the ridge, cut the final ridge cap shingle to fit. Seal the edges of the shingle with caulk.

Finishing Touches and Clean Up

Once the shingles are installed, there are a few finishing touches to complete the project. These include sealing around penetrations, cleaning up the job site, and inspecting the roof for any defects.

Sealing Around Penetrations

Carefully inspect all penetrations, such as chimneys, vents, and skylights. Make sure the shingles are properly sealed around these areas. Use caulk to seal any gaps or cracks. Pay particular attention to areas where water could potentially enter.

For chimneys, you may need to install counterflashing. Counterflashing is a piece of metal flashing that is installed over the base flashing to provide an extra layer of protection against water damage. Consult with a professional if you are unsure how to install counterflashing properly.

Cleaning Up the Job Site

Roofing projects can generate a lot of debris. It’s important to clean up the job site thoroughly to prevent accidents and injuries. Remove all shingle fragments, nails, and other debris from the roof and the surrounding area. Use a magnet to pick up any loose nails.

Dispose of the old shingles and other waste materials properly. Check with your local waste management company for information on how to dispose of roofing materials.

Inspecting the Roof

After completing the project, inspect the roof carefully for any defects. Look for missing shingles, improperly aligned shingles, and any other potential problems. Address any issues promptly to prevent water damage.

It’s also a good idea to inspect the roof after a heavy rain or windstorm. This will help you to identify any potential problems early on.

Safety Precautions

Roofing is a dangerous job. It’s important to take the necessary safety precautions to prevent accidents and injuries. Here are some important safety tips:

  • Wear a safety harness and rope. Secure the rope to a sturdy anchor point on the opposite side of the roof.
  • Wear non-slip shoes. Roofing boots are designed specifically for working on roofs and provide excellent traction.
  • Wear safety glasses and a dust mask. These will protect your eyes and lungs from dust and debris.
  • Use caution when working with power tools. Follow the manufacturer’s instructions and wear appropriate safety gear.
  • Be aware of your surroundings. Watch out for overhead power lines and other hazards.
  • Don’t work on a roof in wet or windy conditions. These conditions can make the roof slippery and increase the risk of falls.
  • If you’re not comfortable working on a roof, hire a professional roofing contractor.

Maintaining Your Asphalt Shingle Roof

Proper maintenance can extend the life of your asphalt shingle roof. Here are some tips for maintaining your roof:

  • Clean your gutters regularly. Clogged gutters can cause water to back up under the shingles and damage the roof deck.
  • Trim trees that are close to the roof. Overhanging branches can damage the shingles and allow leaves to accumulate on the roof.
  • Inspect your roof regularly for signs of damage. Look for missing, cracked, or curled shingles.
  • Repair any damage promptly. Small repairs can prevent major problems down the road.
  • Consider having your roof professionally inspected every few years. A professional roofer can identify potential problems that you may not be able to see.

Conclusion

Applying asphalt shingles is a challenging but rewarding home improvement project. By following the steps outlined in this guide and taking the necessary safety precautions, you can install a new roof that will protect your home for many years to come. Remember to prioritize safety and consult with a professional if you have any questions or concerns. Good luck with your roofing project!