Asphalt shingles are a popular choice for homeowners looking to protect their homes with a reliable and cost-effective roofing material. However, despite their widespread use, replacing asphalt shingles isn’t as straightforward as it might seem. Mistakes during installation can lead to leaks, damage, and a shorter lifespan for your roof. To help you avoid these pitfalls, here’s a guide on the most common mistakes homeowners and contractors often make when replacing asphalt shingles and how to prevent them.
1. Skipping a Thorough Roof Inspection
Before diving into replacing your asphalt shingles, one of the biggest mistakes homeowners make is neglecting a proper roof inspection. Some may think that simply replacing the visible worn or missing shingles is enough, but this overlooks potential damage to the underlying structure.
A roof inspection is vital for identifying underlying issues such as water damage, rot, mold, or issues with the roof decking and flashing. Roofs with hidden structural damage will not benefit from shingle replacement alone. If these problems are ignored, you might end up with leaks or structural issues that could have been addressed before installing the new shingles.
How to Avoid It:
Schedule a professional roof inspection before replacing your shingles. An experienced roofer can identify problems beneath the surface that may need attention before new shingles are installed. If you choose to inspect it yourself, look for signs of water damage, rot, and check your flashing for any signs of rust or cracks.
2. Choosing the Wrong Type of Shingles
It’s easy to be tempted by the lowest-priced shingles or pick the most visually appealing option, but not all shingles are created equal. Asphalt shingles come in a variety of types, and not every shingle is suitable for every climate or roof structure. Homeowners often make the mistake of choosing shingles without considering factors like durability, wind resistance, and UV protection.
For instance, certain areas prone to heavy storms or extreme weather require shingles with higher wind ratings or impact resistance. Choosing the wrong type of shingle for your region could lead to quicker wear and tear, meaning you may have to replace them sooner than expected.
How to Avoid It:
When selecting shingles, consider the local climate and the specific needs of your home. Talk to a roofing professional to help you choose shingles that are durable, weather-appropriate, and long-lasting. Opting for higher-quality shingles initially might be more expensive, but it will save you from frequent repairs or replacements.
3. Improper Nailing Techniques
The way shingles are nailed down is critical to their long-term performance. Improper nailing techniques, such as using too few nails, placing them in the wrong spot, or driving them at the wrong angle, are frequent mistakes that can result in shingles lifting, sliding, or being blown off in windy conditions. Nails that aren’t driven in properly can also create small gaps, allowing water to seep under the shingles and cause damage.
How to Avoid It:
Follow the manufacturer’s instructions for the recommended number of nails per shingle and the correct placement along the nailing strip. Nails should be driven straight and flush with the shingle surface, not at an angle. Be especially careful when nailing along the edges of the roof, where wind uplift can be strongest.
4. Forgetting to Seal Nail Holes
One common mistake often overlooked during shingle replacement is failing to seal the nail holes properly. Exposed or unsealed nail holes provide a direct pathway for water to enter the roof, potentially causing leaks, water damage, and even mold growth over time. Although the shingles themselves are waterproof, nails driven through them can create vulnerabilities if not sealed properly.
Leaving these nail holes exposed, particularly in areas prone to heavy rainfall, significantly increases the risk of moisture infiltration, which can compromise the structural integrity of your roof.
How to Avoid It:
After nailing down your shingles, ensure that each nail hole is sealed using an appropriate roofing sealant. This step adds an extra layer of defense, preventing water from seeping through and causing damage. Pay particular attention to nail holes around roof penetrations like chimneys, vents, or skylights, as these areas are especially prone to leaks.
5. Failing to Remove the Old Shingles
One of the most common shortcuts people take is installing new shingles over an existing layer. This might seem like a way to save time and money, but it’s one of the biggest mistakes you can make. Adding new shingles over old ones creates an uneven surface, prevents the new shingles from sealing properly, and adds unnecessary weight to your roof. Additionally, underlying issues with the roof decking or underlayment go unnoticed and unaddressed.
Skipping the removal of old shingles can lead to roofing issues much sooner than anticipated, shortening the lifespan of your roof.
How to Avoid It:
Always remove the old shingles before installing new ones. This gives you a clear view of the roof deck, allowing you to identify and repair any damage before proceeding with new shingles. It also ensures that the new shingles will lay flat and adhere correctly, providing better protection and durability.
6. Ignoring Roof Ventilation
Roof ventilation plays an essential role in the health of your roof and your home. Without proper ventilation, hot air and moisture can become trapped in your attic, leading to mold growth, warped roof decking, and premature aging of your shingles. Many homeowners fail to assess or improve their roof ventilation system when replacing shingles, not realizing that poor ventilation is one of the top causes of roof damage.
Improper ventilation can also cause ice dams in colder climates, where warm air from the attic melts snow on the roof, which then refreezes at the roof’s edge, creating dangerous ice buildup.
How to Avoid It:
Ensure your roof has proper ventilation by installing ridge vents, soffit vents, or other types of exhaust and intake vents to allow air to circulate freely. If you’re not sure whether your attic is well-ventilated, consult a roofing expert for advice on how to improve it.
7. Misaligning Shingles
Misalignment of shingles can lead to a roof that not only looks unattractive but also allows water to penetrate. Poorly aligned shingles create gaps and valleys where water can pool, leading to leaks and water damage. Shingles must be laid in straight rows with the correct amount of overlap for the roof to remain watertight.
How to Avoid It:
Use a chalk line to mark each row and ensure your shingles are aligned properly. Pay extra attention to keeping them level as you work across the roof. Taking the time to align each row perfectly will protect your roof from future problems and improve its visual appeal.
8. Skipping Drip Edge Flashing
Drip edge flashing is a thin metal strip installed along the roof’s edges to direct water away from the roof and into the gutters. Surprisingly, many roofers or homeowners skip this step, thinking it’s unnecessary. However, without drip edge flashing, water can seep under the shingles and into the roof decking, causing rot and structural damage over time.
How to Avoid It:
Always install drip edge flashing along the edges of your roof. It provides an extra layer of protection by guiding water safely off the roof and into your gutter system. Skipping this step may lead to costly repairs down the road.
9. Overlooking the Underlayment
The underlayment is a waterproof or water-resistant layer installed between the roof decking and the shingles. It serves as an extra barrier against moisture. Neglecting to install underlayment or using a substandard product can leave your roof vulnerable to leaks, especially during heavy rains or storms.
How to Avoid It:
Invest in high-quality underlayment and ensure it’s installed properly. This layer is your roof’s second line of defense, so don’t skip it. Make sure the underlayment is installed according to manufacturer guidelines for maximum protection.
10. Replacing Shingles in Bad Weather
Roofing during bad weather conditions is another major mistake. High winds, rain, snow, or extreme temperatures can make it difficult to install shingles correctly. Cold weather can cause shingles to become brittle, while extreme heat can make them overly pliable, both of which can lead to improper installation and shorter lifespan.
How to Avoid It:
Plan your roofing project for a time when the weather is mild and dry. This allows for proper installation and ensures the shingles have time to adhere correctly without being compromised by weather conditions.
11. Taking the DIY Route Without Expertise
Lastly, many homeowners attempt to replace their asphalt shingles themselves without the necessary experience or knowledge. While DIY projects can be rewarding, roofing is a complex task that requires precision, safety measures, and a deep understanding of how roofing systems work. Mistakes made during DIY roof replacement often lead to higher costs in repairs or early roof failure.
How to Avoid It:
If you’re not experienced with roofing, it’s best to hire a professional. A certified roofing contractor has the expertise to ensure the job is done right the first time. While it may seem like a bigger upfront investment, hiring a professional can save you money in the long run by preventing costly mistakes.
Conclusion
Replacing asphalt shingles is a significant investment in your home’s protection and longevity. Avoiding common mistakes like neglecting inspections, choosing the wrong shingles, or using improper installation techniques can make the difference between a durable roof and one that fails prematurely. By taking the time to address key issues—such as ventilation, proper nailing, and ensuring the right materials are used—you can guarantee that your new roof will stand the test of time.
Whether you choose to handle the project yourself or hire a professional, remember that attention to detail and proper planning are essential to ensuring long-term success. A well-executed roof replacement will not only enhance the look of your home but also provide peace of mind, knowing that your investment will pay off for years to come.
