Spotting Improper Roof Installation Signs: Key Tips

Buying a new roof is a considerable investment. And you want to make sure you’re making an intelligent decision for your biggest asset: your house. Although it can be tempting to go with the roofing contractor offering the most affordable bid, this could cost you more money in the long run, especially if those roofers cut corners or lack experience. Knowing the signs of improper roof installation can save you a massive headache later. This article will give you the tools you need to determine if your roof has been correctly installed or needs attention.

Telltale Signs of Improper Roof Installation

You can quickly and easily tell when some things are wrong, for example, mismatched paint or crooked tilework. But you might need to figure out what to look for with your roof. Fortunately, you can spot many improper roof installation signs with the naked eye once you know what to look for.

Shingle Issues

Shingles are one of the most obvious signs that something isn’t right with your roof. They’re the easiest to examine because they’re the outermost layer of your roofing system. A good, sturdy roof has a uniform appearance, and anything that deviates from this norm is a sign of potential roofing problems.

Wavy Shingles

A properly installed roof is supposed to have clean, straight lines, so when your roof has a wavy or uneven appearance, that indicates that the asphalt shingles were improperly installed.

This happens when your roofer doesn’t take the time to measure accurately and snap chalk lines onto the roof decking. Chalk lines guide roofers in installing shingles in a straight line, which, with improper installations, can make the finished product appear aesthetically crooked and can also result in leaks down the line.

Shingle Overhang

Next, check out the eaves and rakes (the edges of your roof). Do you see your shingles extending too far over the edge or not far enough?

According to IKO, one of North America’s largest roofing manufacturers, shingle overhang at the eaves should be about ¾ of an inch. Too much overhang puts the shingles at risk of blowing off in high winds. But if the shingles don’t overhang enough, water can seep back under the shingles and into your fascia board. This can lead to rotted wood.

Missing or Damaged Shingles

Damaged or missing shingles can result from severe weather, such as hailstorms, but they also commonly happen due to bad installation practices. One of the biggest culprits is improper nailing.

Nail Problems

Asphalt shingles require specific roofing nails and a “face nailing” technique to be secured correctly. These nails are shorter than standard nails and have a broader head, helping create a solid bond with the roofing material.

These nails must be driven straight into the nail line, a section just below the shingle’s top edge. This line might not always be visible to the naked eye. However, improper nailing will make itself known sooner rather than later through leaks or shingle blow-offs after a storm. If the nail isn’t driven in far enough, it won’t be flush with the shingle surface, and wind uplift could catch the raised nail head and rip the shingles right off the roof. You also run the risk of moisture infiltrating the nail hole and causing leaks or rot.

Conversely, if the nail is overdriven and sinks beneath the shingle’s surface, it won’t hold the shingle down as securely as it should, increasing the chances of shingle uplift. A roofing job with nail problems can cause your roof to perform poorly, leading to necessary repairs sooner than usual.

Incorrect Shingle Offsetting

Like bricks or tiles, shingles have an offset pattern, too. This offset pattern isn’t just for looks—it’s vital for protecting the roof. Imagine each shingle acting as a shield against rain and debris, with each layer slightly overlapping the one beneath it.

Without proper offset, you increase your chances of vulnerable spots on the roof that allow water damage. Misaligned shingles are a common roof installation problem that can lead to a bad roof.

Roof Flashing Gaps and Mistakes

Flashing is a thin metal material, often made of aluminum or galvanized steel. Its job is to prevent leaks. Flashing is installed in valleys and around anything that sticks out of the roof, like dormers, skylights, chimneys, or vent stacks, because these areas are especially vulnerable to leaks.

You’ll know if a roofer made mistakes while installing flashing because you’ll likely find evidence of leaks. Reused flashing and missing underlayment are also signs of poor roof installation.

Improper Gutter Installation

Even if your roof is installed perfectly, improper gutter installation can also spell disaster down the line. If your gutters are uneven, water backs up and causes costly issues such as mold, mildew, soil erosion around the foundation of your house, or even leaks that cause severe structural damage.

Your contractor should know the proper gutter system to use with your type of roof and how to position them so water effectively drains away from your house.

Working With Unlicensed, Inexperienced Contractors

One of the biggest signs you might be looking at an improper roof installation is if the company you hired is unlicensed, uninsured, or lacks proper experience. Always make sure the roofing contractor you work with is a reputable roofing company. Getting a few different inspections and estimates can help determine this.

Are you unsure if your contractor is licensed? Check with the Better Business Bureau or local government website. A roof is too important to leave to an amateur—make sure you research reviews and experience before handing over the job (and thousands of your hard-earned dollars) to a contractor. Winter roof installation can be especially challenging, so make sure your roofing contractors have experience with winter roofing during the colder seasons.

FAQs about Improper Roof Installation Signs

How can I be sure that my roof has been properly installed?

Identifying every nuance of improper installation might be tricky unless you’re a roofing expert. If you’re unsure about anything, your best bet is to get a professional roof inspection. But don’t wait. The longer you wait to bring in help, the more damage your roof (and home) might sustain.

What is the average cost to replace an entire roof?

Costs vary based on the materials used and your roof’s size and pitch. But you can generally expect to pay around $4 to $40 per square foot. To find the total square footage of your roof, multiply the length by width.

Of course, be sure to consult with several reputable roofing contractors in your area to get an accurate estimate for your roof replacement.


Spotting subtle signs of improper roof installation before they become massive headaches can be empowering and save you thousands of dollars down the road on repairs or even a complete roof replacement. Remember, your roof is a major component of your home’s protection. Paying attention to details—and addressing potential issues promptly—is a smart move for any homeowner.

  • Fidelity Roofing, Inc
  • 1725 McRee Rd., Newton, North Carolina 28658
  • Monday - Friday: 9:00am - 5:00pm
  • Saturday, Sunday: Closed
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