7 Common Mistakes to Avoid During Roof Replacement

What is the Roof Replacement Process?

A comprehensive roof replacement involves several steps, each of which is critical to the success of the project.

1. Inspection: This initial step involves a thorough assessment of your roof’s current condition. A professional roofer will look for signs of wear, damage, and potential problem areas. This helps determine whether a roof replacement is necessary and what specific areas need attention.

2. Tear-Off: During a roof replacement, the old roofing materials, including shingles, underlayment, and flashing, are removed. This allows the contractor to assess the decking (the wooden surface that supports the roof) and repair any damage.

3. Decking Repair: If the decking shows signs of rot, water damage, or other issues, it will need to be repaired or replaced. A solid, undamaged decking is crucial for the longevity of your new roof.

4. Underlayment Installation: Underlayment is a protective barrier that sits between the decking and the shingles. It provides an additional layer of protection against water infiltration.

5. New Roofing Material Installation: This is the most visible part of the roof replacement process. The new shingles or other roofing materials are installed according to manufacturer guidelines to ensure maximum durability and protection. The cost of a roof replacement typically ranges from $6,700 to $80,000, with the average-sized home costing around $11,500.

6. Flashing and Ventilation: Flashing, typically made of metal, is installed around areas like chimneys, vents, and skylights to prevent water from seeping into your home. Proper ventilation is also crucial, as it helps regulate temperature and moisture levels in your attic, extending the life of your roof.

7. Final Inspection: Once the roof replacement is complete, a final inspection ensures that everything has been installed correctly and that no issues have been overlooked.

Common Signs It’s Time for a Roof Replacement

Recognizing when it’s time for a roof replacement can save you from more extensive and expensive repairs later on. Here are some common signs that indicate a roof replacement might be necessary:

1. Age of the Roof: The age of your roof is one of the most telling indicators. Most roofing materials, such as asphalt shingles, have a lifespan of 20-25 years. However, roofs generally need replacing every 12 to 50 years, depending on the materials used and environmental factors. If your roof is approaching this age, it’s time to consider a roof replacement, even if there are no visible issues.

2. Leaks and Water Damage: Persistent leaks or visible water damage in your attic, ceilings, or walls are strong indicators that your roof may be failing. Water stains, mold growth, and damp spots are all signs that a roof replacement is needed to prevent further damage to your home.

3. Missing or Damaged Shingles: Shingles that are cracked, curled, or missing entirely indicate that your roof is deteriorating. These issues can lead to leaks and should be addressed promptly through a roof replacement.

4. Granule Loss: Shingles are coated with granules that protect them from UV rays and provide fire resistance. If you notice an excessive amount of granules in your gutters, it’s a sign that your shingles are nearing the end of their life, and a roof replacement may be necessary.

5. Sagging Roof Deck: A sagging roof deck is a serious issue that often necessitates a roof replacement. This problem indicates structural damage that must be addressed to ensure the safety of your home.

7 Common Mistakes to Avoid During Roof Replacement

When undertaking a roof replacement, it’s essential to be aware of common pitfalls that can compromise the quality and longevity of your new roof.

1. Using Mismatched Roofing Shingles

One of the most visible and easily avoidable mistakes during a roof replacement is using mismatched shingles. This can happen when a contractor uses leftover materials from previous jobs or when a homeowner tries to cut costs by purchasing discounted, mismatched shingles.

Why It’s a Problem

• • Aesthetic Consistency: Mismatched shingles can create an inconsistent look, diminishing the overall appearance of your home. This inconsistency is especially noticeable from the street, reducing your home’s curb appeal and potentially affecting its resale value.

• • Material Integrity: Different shingles may have varying lifespans, leading to uneven wear. As some shingles degrade faster than others, you might find yourself facing another roof replacement sooner than expected.

How to Avoid It

• • Order Carefully: Ensure that your contractor orders the correct amount of shingles from the same manufacturer and batch. This guarantees that all shingles will match in color, size, and texture.

• • Inspect Materials: Before installation begins, inspect the shingles to confirm they match. If you notice any discrepancies, address them immediately with your contractor to avoid problems down the line.

2. Overlaying an Existing Roofing System

Some homeowners opt to overlay a new roofing system on top of the old one rather than doing a complete tear-off. While this might seem like a cost-effective solution, it can lead to significant problems down the line.

Why It’s a Problem

• • Hidden Damage: Overlaying can hide existing damage, such as rot, mold, or leaks, which can worsen over time. This hidden damage can compromise the structural integrity of your roof and home.

• • Increased Weight: Adding another layer of shingles increases the weight on your roof, which can stress the structural integrity of your home. This added weight can lead to sagging or even structural failure in extreme cases.

• • Poor Ventilation: Overlays can affect ventilation, leading to moisture buildup and reduced energy efficiency. Poor ventilation can also cause shingles to overheat, reducing their lifespan and effectiveness.

How to Avoid It

• • Opt for a Tear-Off: Always opt for a complete tear-off during a roof replacement. This allows for a thorough inspection of the decking and ensures that any underlying issues are addressed. A tear-off might cost more upfront, but it can save you from more expensive repairs in the future.

3. Underlayment Issues

The underlayment acts as a protective barrier between the decking and the shingles, helping to prevent moisture from seeping into your home. However, mistakes during underlayment installation can lead to significant problems.

Why It’s a Problem

• • Moisture Intrusion: Incorrect or poorly installed underlayment can allow water to penetrate the roof deck, leading to rot and mold. Over time, this can compromise the structural integrity of your roof and even lead to costly repairs or another roof replacement.

• • Reduced Lifespan: Without proper underlayment, the lifespan of your new roof could be significantly shortened. Any issues with its installation can reduce the effectiveness of your entire roofing system.

How to Avoid It

• • Use Quality Materials: Ensure that a high-quality underlayment is used for your roof replacement. This includes materials that are appropriate for your specific climate and roofing system.

• • Ensure Proper Installation: Work with a contractor who understands the importance of underlayment and has experience in its proper installation. The underlayment should be installed without gaps, overlaps, or wrinkles that could compromise its effectiveness.

4. Improper Use of Roofing Nails

Roofing nails may seem like a minor detail, but they play a crucial role in securing your roofing materials. Improper nailing techniques can lead to a host of problems that compromise the integrity of your roof replacement.

Why It’s a Problem

• • Loose Shingles: Over- or under-driven nails can result in loose shingles, which are more susceptible to wind damage. Loose shingles can easily be torn off during storms, leaving your roof vulnerable to leaks and other damage.

• • Leaks: Incorrectly placed nails can create gaps that allow water to seep in, leading to leaks. These leaks can cause water damage inside your home and may require costly repairs.

How to Avoid It

• • Use the Correct Nails: Ensure that your contractor uses the correct size and type of nails for your specific roofing materials. Roofing nails should be long enough to penetrate the shingle and at least 3/4 inch into the decking.

• • Proper Nailing Technique: Nails should be driven straight and just below the shingle surface without over-penetrating. Over-driven nails can cut through shingles, while under-driven nails can prevent the shingles from lying flat. Both scenarios can lead to problems with your roof replacement.

5. Too Short or Long Overhang at the Eaves

The overhang of your roof, or the portion that extends beyond the walls of your home, is essential for protecting your home from water damage. However, getting the overhang length wrong can cause issues during and after your roof replacement.

Why It’s a Problem

• • Too Short: An overhang that is too short can lead to water running down the walls, causing damage to the siding and foundation. This can result in issues such as mold growth, wood rot, and even foundation problems.

• • Too Long: An overhang that is too long can be lifted by strong winds, potentially damaging the roof. Long overhangs can act like sails, catching the wind and putting stress on the roof structure.

How to Avoid It

• • Determine the Right Overhang Length: The overhang should be long enough to direct water away from the walls but not so long that it becomes a liability in high winds. The ideal length depends on the architecture of your home and the local climate.

• • Consult with Your Contractor: Work with a contractor who understands the importance of proper overhang length and can calculate the correct dimensions for your roof. This will ensure that your roof replacement not only looks good but also performs well in protecting your home.

6. Not Adhering to Roof Slope

The slope or pitch of your roof is a critical factor in determining the type of roofing materials that should be used. Using materials not suited to your roof’s slope is a common mistake during roof replacement.

Why It’s a Problem

• • Water Accumulation: If the slope is too shallow for the chosen material, water can accumulate, leading to leaks and potential roof failure. Flat or low-slope roofs require special materials designed to prevent water pooling.

• • Reduced Lifespan: Roofing materials not designed for a specific slope will not perform as intended, reducing the lifespan of the roof. For example, traditional shingles may not be suitable for low-slope roofs because they rely on gravity to shed water.

How to Avoid It

• • Select the Right Materials: Ensure that the roofing materials selected are appropriate for your roof’s slope. This may involve using materials such as metal roofing, rubber membranes, or modified bitumen for low-slope roofs.

• • Consult with Your Contractor: Discuss the slope of your roof with your contractor and ensure they select materials that are suitable for the pitch of your roof. This will help ensure your roof replacement is durable and effective in shedding water.

7. Neglecting to Get a Roofing Permit

Skipping the permitting process is a mistake that can have serious consequences. While it might be tempting to avoid the hassle, especially if you’re working with a contractor who doesn’t insist on it, not getting a roofing permit can lead to problems.

Why It’s a Problem

• • Legal Issues: Without a permit, your roof replacement may not be up to code, leading to fines and the potential need for rework. Building codes exist to ensure that construction projects are safe and meet certain standards. 

• • Insurance Problems: Your insurance company may refuse to cover any claims related to the roof if the work is done without a permit. If something goes wrong with your roof replacement, you could be left footing the bill for repairs or even a complete re-roofing.

• • Resale Complications: When you go to sell your home, an unpermitted roof replacement can become a sticking point in the sale process. Buyers may be hesitant to purchase a home with unpermitted work, or they may demand a lower price.

How to Avoid It

• • Check Local Regulations: Always check with your local building department to determine if a permit is required for your roof replacement. Requirements can vary depending on your location and the scope of the work.
  • Work with a Reputable Contractor: Choose a contractor who includes the permitting process in their services. A good contractor will handle the paperwork and ensure that all work complies with local building codes.