Laying Asphalt Shingles

Laying Asphalt Shingles: A Comprehensive Guide

So, you’re thinking about tackling a roofing project? Specifically, laying asphalt shingles? That’s fantastic! While it’s definitely a significant undertaking, with the right preparation, knowledge, and a healthy dose of patience, it’s absolutely achievable. This guide will walk you through every step of the process, from initial assessment to final cleanup, ensuring you have all the information you need to complete the job successfully. We’ll be using a fairly casual, yet professional tone here, so it’s like you’re getting advice from a knowledgeable friend who’s done this a time or two (or ten!). Remember, safety is paramount. Always wear appropriate safety gear and if you’re uncomfortable with any part of the process, don’t hesitate to call in a professional.

Assessing the Project and Gathering Materials

Before you even think about climbing up onto that roof, let’s take a good, hard look at what you’re getting into. This initial assessment is crucial for determining the scope of the project, estimating costs, and ensuring you have all the necessary materials.

Inspecting the Existing Roof (If Applicable)

If you’re replacing an existing roof, the first step is a thorough inspection. Look for these key things:

Damage: Obvious signs like missing, cracked, or curled shingles are a dead giveaway. Also, check for water stains or leaks in the attic, which indicate more serious problems.
Underlayment Condition: Is the underlayment (the layer underneath the shingles) damaged or deteriorated? This will need to be replaced along with the shingles.
Decking Condition: The decking (the wooden sheathing that the shingles are nailed to) is the foundation of your roof. Check for rot, water damage, or loose nails. Soft spots are a major red flag. You might need to replace sections of decking before laying new shingles.
Flashing: Flashing is the metal used around chimneys, vents, and skylights to prevent water intrusion. Check for rust, corrosion, or damage to the flashing. Damaged flashing needs to be replaced.
Ventilation: Proper roof ventilation is essential for preventing moisture buildup and extending the life of your shingles. Make sure your existing vents are functioning properly and aren’t blocked by debris.

Document everything you find with photos and notes. This will help you create an accurate materials list and budget.

Determining the Square Footage

This is critical for ordering the correct amount of shingles. Here’s how to calculate the square footage:

Measure the Length and Width: Measure the length and width of each rectangular section of your roof.
Calculate Area: Multiply the length and width of each section to find its area.
Add it All Up: Add the areas of all the sections together to get the total roof area.
Convert to Squares: Roofing materials are typically sold in “squares,” which represent 100 square feet. Divide the total roof area (in square feet) by 100 to determine the number of squares you need.
Add Waste: It’s always a good idea to add some extra shingles to account for waste during installation and for future repairs. A good rule of thumb is to add 10-15% to your total square footage. For complex roofs with many angles and valleys, you might want to add even more.

For example, if your roof is 2,000 square feet, you’ll need 20 squares of shingles. Adding 10% for waste means ordering 22 squares.

Creating a Materials List

Here’s a comprehensive list of materials you’ll likely need:

Asphalt Shingles: Choose the type and color you want. Consider architectural shingles for a more premium look.
Underlayment: Synthetic underlayment is generally preferred over felt paper for its superior durability and water resistance.
Drip Edge: Metal flashing installed along the edges of the roof to prevent water from wicking back under the shingles.
Flashing: For chimneys, vents, skylights, and valleys. Aluminum or galvanized steel are common choices.
Roofing Nails: Use galvanized roofing nails of the correct length for your shingle type and roof decking thickness. Consult the shingle manufacturer’s instructions.
Roofing Cement: For sealing around flashing and other penetrations.
Ventilation Materials: Ridge vents, soffit vents, or other types of ventilation to ensure proper airflow.
Starter Shingles: Specifically designed for the first course of shingles.
Ice and Water Shield: (Optional, but recommended in areas with heavy snow or ice) Applied along the eaves and in valleys to prevent water damage from ice dams.
Safety Equipment: Roofing harness, safety ropes, non-slip shoes, hard hat, safety glasses, gloves.
Tools: Roofing hammer or nail gun, utility knife, measuring tape, chalk line, pry bar, shingle remover (if replacing an existing roof), ladder, and possibly a dumpster for debris.

Remember to check with your local building codes for any specific requirements regarding roofing materials or installation methods.

Ordering and Storing Materials

Order your materials well in advance of your project start date to ensure they’re available when you need them. When the materials arrive, store them in a dry, well-ventilated area, preferably off the ground on pallets. Cover them with a tarp to protect them from the elements. Shingles are heavy, so be careful when lifting and moving them. Don’t stack them too high, as this could damage the shingles or cause them to fall.

Preparing the Roof Surface

Proper preparation is key to a long-lasting and watertight roof. This involves removing the old shingles (if applicable), inspecting and repairing the decking, and installing the underlayment.

Removing the Old Shingles

Removing the old shingles can be a tedious and dusty job, but it’s essential for ensuring a clean and solid base for the new shingles. Here’s how to do it:

Safety First: Wear safety glasses, gloves, and a dust mask.
Start at the Top: Begin at the top of the roof and work your way down.
Use a Shingle Remover: A shingle remover tool will make the job much easier. It’s designed to slide under the shingles and pry them up with minimal effort.
Pry Up the Nails: If the shingles are nailed down tightly, use a pry bar to lift them and remove the nails.
Dispose of the Old Shingles: Place the old shingles in a dumpster or other designated disposal container.
Remove All Debris: Once all the shingles are removed, sweep the roof deck clean of any debris, such as nails, granules, and old underlayment.

Be careful not to damage the roof decking during the removal process. If you encounter any damaged areas, repair them before proceeding.

Inspecting and Repairing the Decking

With the old shingles removed, you can now thoroughly inspect the roof decking. Look for:

Rot: Soft, spongy areas indicate rot. Use a screwdriver to probe suspect areas. If the screwdriver easily penetrates the wood, it’s likely rotten.
Water Damage: Stains, discoloration, or warping can indicate water damage.
Loose Nails: Hammer in any loose nails or replace them with new ones.
Sagging: Sagging areas indicate structural problems that need to be addressed. This might require replacing sections of the decking or reinforcing the rafters.

To repair damaged decking, cut out the affected section with a circular saw and replace it with a new piece of plywood or OSB of the same thickness. Secure the new decking to the rafters with screws or nails. Make sure the edges of the new decking are flush with the existing decking.

Installing the Underlayment

Underlayment is a crucial layer of protection that helps prevent water from penetrating the roof deck. It also provides a smooth surface for the shingles to adhere to.

Start at the Eaves: Begin at the bottom edge of the roof (the eaves) and roll out the underlayment horizontally.
Overlap: Overlap each course of underlayment by at least 2 inches (or as specified by the manufacturer).
Secure with Staples: Use roofing staples to secure the underlayment to the roof deck. Space the staples about 12 inches apart along the edges and 24 inches apart in the field.
Ice and Water Shield (Optional): In areas with heavy snow or ice, install ice and water shield along the eaves, in valleys, and around any penetrations. This self-adhesive membrane provides an extra layer of protection against water damage from ice dams.
Follow Manufacturer’s Instructions: Always follow the manufacturer’s instructions for installation.

Make sure the underlayment is smooth and wrinkle-free. Any wrinkles or bumps can telegraph through the shingles and affect their appearance.

Installing the Asphalt Shingles

Now for the main event! Installing the asphalt shingles is where your hard work really pays off. This section will cover the essential steps for laying shingles properly and creating a durable, attractive roof.

Installing the Drip Edge

The drip edge is a metal flashing that is installed along the edges of the roof to prevent water from wicking back under the shingles. It also helps to protect the fascia board from water damage.

Install Along the Eaves First: Start by installing the drip edge along the eaves (the bottom edge of the roof).
Overlap at Corners: Overlap the drip edge at corners by a few inches.
Nail Securely: Nail the drip edge to the roof deck with roofing nails. Space the nails about 12 inches apart.
Install Along the Rakes: Next, install the drip edge along the rakes (the sloping edges of the roof). Overlap the drip edge at the eaves.

Make sure the drip edge is securely attached to the roof deck. A loose or improperly installed drip edge can allow water to penetrate the roof and cause damage.

Installing 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 first course of full shingles and helps to seal the edges of the roof.

Use Starter Shingles: Use starter shingles specifically designed for this purpose. These shingles are typically narrower than full shingles and have a self-adhesive strip along the bottom edge.
Position the Starter Shingles: Position the starter shingles so that the self-adhesive strip is aligned with the bottom edge of the roof.
Overlap: Overlap the starter shingles by a few inches at the seams.
Nail Securely: Nail the starter shingles to the roof deck with roofing nails. Use the same nailing pattern as you would for full shingles.

Alternatively, you can create a starter course by cutting the tabs off of full shingles and installing them upside down along the eaves.

Laying the First Course of Shingles

The first course of full shingles is installed directly above the starter course. This is a critical row, as it sets the alignment for all the subsequent rows.

Align the Bottom Edge: Align the bottom edge of the first course of shingles with the bottom edge of the starter course.
Overlap: Overlap the shingles according to the manufacturer’s instructions. This is typically around 5-6 inches.
Nail Correctly: Nail the shingles to the roof deck with roofing nails. Use the correct nailing pattern as specified by the manufacturer. This is usually four nails per shingle, placed just below the sealant strip. Make sure the nails are driven straight and flush with the shingle surface. Overdriving the nails can damage the shingles and compromise their water resistance.

Pay close attention to the alignment of the first course. If it’s not straight and true, it will throw off the alignment of all the subsequent rows.

Laying Subsequent Courses

Once you’ve laid the first course, you can continue laying subsequent courses, overlapping each course according to the manufacturer’s instructions. This creates a staggered pattern that helps to shed water and prevents leaks.

Stagger the Seams: Stagger the seams of each course by half the width of a shingle. This ensures that no two seams are directly above each other, which could create a weak spot in the roof.
Maintain Alignment: Use a chalk line to maintain alignment as you lay each course. This will help to ensure that the shingles are straight and true.
Proper Nailing: Again, ensure correct nailing as specified by the manufacturer. Use the correct nailing pattern and drive the nails straight and flush with the shingle surface.
Work Your Way Up: Continue working your way up the roof, laying each course of shingles until you reach the ridge.

Take your time and pay attention to detail. A well-laid roof is a thing of beauty that will provide years of protection for your home.

Cutting Shingles Around Obstacles

You’ll likely need to cut shingles to fit around obstacles such as chimneys, vents, and skylights. Here’s how to do it:

Measure Carefully: Measure the distance from the edge of the obstacle to the nearest shingle.
Mark the Shingle: Transfer the measurement to the shingle and mark the cut line.
Cut with a Utility Knife: Use a utility knife to cut the shingle along the marked line. You may need to score the shingle several times to cut through it completely.
Test the Fit: Test the fit of the cut shingle around the obstacle. Make any necessary adjustments.
Seal with Roofing Cement: Seal the edges of the cut shingle with roofing cement to prevent water from penetrating.

Be careful when cutting shingles around obstacles. Use a sharp utility knife and work in a well-ventilated area.

Installing Flashing

Flashing is used to seal around chimneys, vents, skylights, and valleys to prevent water intrusion. It’s a critical component of a watertight roof.

Chimney Flashing: Chimney flashing typically consists of base flashing, counter flashing, and step flashing.

Base Flashing: The base flashing is installed around the base of the chimney, overlapping the shingles.
Counter Flashing: The counter flashing is embedded in the chimney mortar joints and overlaps the base flashing.
Step Flashing: Step flashing is used along the sides of the chimney, overlapping each course of shingles.

Vent Flashing: Vent flashing is installed around roof vents to prevent water from entering the vent opening.

Skylight Flashing: Skylight flashing is specifically designed to seal around skylights.

Valley Flashing: Valley flashing is installed in roof valleys, where two roof slopes meet. This area is particularly vulnerable to water damage, so proper flashing is essential.

Install Valley Flashing First: If your roof has valleys, install the valley flashing before laying the shingles.
Use Metal Flashing: Use metal flashing, such as aluminum or galvanized steel.
Overlap Properly: Overlap the flashing according to the manufacturer’s instructions.
Seal with Roofing Cement: Seal the edges of the flashing with roofing cement to prevent water from penetrating.

Proper flashing installation is critical to preventing leaks. If you’re not comfortable installing flashing, it’s best to hire a professional.

Installing the Ridge Cap

The ridge cap is the final row of shingles that is installed along the ridge of the roof. It seals the ridge and provides a finished look.

Use Ridge Cap Shingles: Use ridge cap shingles specifically designed for this purpose. These shingles are typically wider than full shingles and are pre-bent to fit over the ridge.
Overlap Properly: Overlap the ridge cap shingles according to the manufacturer’s instructions.
Nail Securely: Nail the ridge cap shingles to the roof deck with roofing nails. Use the same nailing pattern as you would for full shingles.
Seal with Roofing Cement: Seal the edges of the ridge cap shingles with roofing cement to prevent water from penetrating.

The ridge cap completes the roof and provides a clean, finished look.

Final Inspection and Cleanup

Once you’ve finished laying the shingles, it’s time for a final inspection and cleanup. This is your chance to catch any mistakes and ensure that the roof is properly sealed and protected.

Inspect the Roof Carefully

Walk around the roof and inspect it carefully for any of the following:

Missing Shingles: Make sure all shingles are in place and securely attached.
Loose Nails: Hammer in any loose nails.
Misaligned Shingles: Correct any misaligned shingles.
Damaged Shingles: Replace any damaged shingles.
Improper Flashing: Check the flashing around chimneys, vents, skylights, and valleys to make sure it’s properly installed and sealed.
Sealant: Make sure all sealant is properly applied and that there are no gaps or cracks.

Pay particular attention to areas that are prone to leaks, such as valleys, chimneys, and vents.

Clean Up the Job Site

Once you’ve completed the inspection, it’s time to clean up the job site. This includes:

Removing All Debris: Remove all debris, such as nails, shingle scraps, and roofing cement containers.
Sweeping the Roof: Sweep the roof clean of any granules or other debris.
Checking the Gutters: Check the gutters for any debris and clean them out if necessary.
Disposing of Waste Properly: Dispose of all waste materials properly, according to local regulations.

A clean job site is a safe job site.

Document Your Work

Take photos of the finished roof from different angles. This will be helpful for insurance purposes and for future reference. Keep records of all materials used and the dates of installation.

Safety Considerations

Roofing is a dangerous job, and it’s important to take safety precautions to prevent accidents. Here are some important safety considerations:

Wear Appropriate Safety Gear: Always wear a roofing harness, safety ropes, non-slip shoes, a hard hat, safety glasses, and gloves.
Use a Sturdy Ladder: Use a sturdy ladder that is long enough to reach the roof safely. Make sure the ladder is properly secured and that it’s placed on a level surface.
Work in Good Weather: Avoid working on the roof in wet, windy, or icy conditions.
Be Aware of Your Surroundings: Be aware of your surroundings and watch out for power lines, trees, and other obstacles.
Take Breaks: Take frequent breaks to avoid fatigue.
Don’t Work Alone: It’s always best to work with a partner.
Communicate Clearly: Communicate clearly with your partner and let them know what you’re doing.
Know Your Limits: If you’re not comfortable with any part of the process, don’t hesitate to call in a professional.

Safety is always the top priority. Don’t take any unnecessary risks.

Troubleshooting Common Problems

Even with the best planning and execution, problems can sometimes arise during a roofing project. Here are some common problems and how to troubleshoot them:

Leaking Roof: If you notice a leak after installing the shingles, the first step is to identify the source of the leak. Check the flashing around chimneys, vents, skylights, and valleys. Also, check for damaged or missing shingles. Once you’ve identified the source of the leak, repair it as needed. This might involve replacing damaged shingles, resealing flashing, or installing new flashing.
Blown-Off Shingles: If shingles are blown off the roof during a storm, replace them as soon as possible. Make sure to use the correct nailing pattern and seal the edges of the shingles with roofing cement. Consider using a heavier-duty shingle in areas that are prone to high winds.
Granule Loss: Some granule loss is normal, especially during the first few months after installation. However, excessive granule loss can indicate a problem with the shingles. If you notice excessive granule loss, contact the shingle manufacturer for advice.
Algae Growth: Algae can grow on asphalt shingles, especially in humid climates. This can cause the shingles to become discolored and unsightly. To prevent algae growth, consider using algae-resistant shingles. You can also clean the shingles with a mild bleach solution.

If you encounter any problems that you’re not comfortable troubleshooting, it’s best to call in a professional roofer.

When to Call a Professional

While DIY roofing is possible, there are definitely situations where it’s best to call in a professional. Consider hiring a professional roofer if:

You’re Not Comfortable Working at Heights: Roofing is a dangerous job, and if you’re not comfortable working at heights, it’s best to leave it to the professionals.
You Have a Complex Roof: Complex roofs with many angles, valleys, and penetrations can be challenging to roof. A professional roofer will have the experience and expertise to handle these types of roofs.
You Don’t Have the Time or Skills: Roofing is a time-consuming and labor-intensive job. If you don’t have the time or skills to do it properly, it’s best to hire a professional.
You’re Unsure About Building Codes: Roofing projects are subject to local building codes. A professional roofer will be familiar with these codes and will ensure that your roof meets all requirements.
You Encounter Unexpected Problems: If you encounter unexpected problems during the project, such as damaged decking or hidden leaks, a professional roofer will be able to assess the situation and provide solutions.

Hiring a professional roofer can be more expensive than doing it yourself, but it can also save you time, money, and headaches in the long run. A professionally installed roof will be more durable, watertight, and long-lasting.

Conclusion

Laying asphalt shingles is a significant undertaking, but with careful planning, preparation, and execution, it’s an achievable DIY project. Remember to prioritize safety, follow the manufacturer’s instructions, and take your time. A well-laid roof will protect your home for years to come. And if you ever feel overwhelmed or unsure, don’t hesitate to call in a professional. Good luck!