Is It OK To Reroof Over Old Shingles?

If you find yourself wondering whether it’s permissible or advisable to re-roof over old shingles, you’re not alone. Many homeowners are unsure about the best course of action when it comes to replacing or adding new shingles to a roof that already has an existing layer. In this article, we will explore whether re-roofing over old shingles is acceptable and the potential advantages and disadvantages of doing so. By the end, you’ll have a clearer understanding of how to approach this common roofing dilemma.

The Pros of Reroofing Over Old Shingles

Time and Cost Savings

Reroofing over old shingles can offer significant time and cost savings compared to a complete roof tear-off and replacement. When you choose to reroof, there is no need to remove the existing shingles, which can be a time-consuming and labor-intensive process. This means that the overall installation time is reduced, allowing you to quickly have a new roof without the hassle of a lengthy construction project. Additionally, the cost of labor and disposal fees associated with removing and disposing of the old shingles is eliminated, resulting in potential cost savings.

Reduced Environmental Impact

By opting to reroof over old shingles, you can contribute to a reduced environmental impact. Roof tear-offs generate a significant amount of waste that ends up in landfills. By avoiding a complete replacement, you can help reduce the amount of roofing material waste being disposed of, thereby minimizing your environmental footprint. Reroofing allows for the reuse of the existing shingles, which helps conserve resources and promotes sustainability.

Preserving the Existing Roofing Material

Reroofing over old shingles also allows you to preserve the existing roofing material. If the old shingles are still in relatively good condition and free from significant damage, reroofing can provide an opportunity to extend the life of the roofing system. This preservation of the existing shingles can be especially beneficial if they are made from high-quality materials or if they possess unique aesthetic qualities that you wish to maintain. By preserving the existing material, you can also retain the original character and charm of your home.

Minimal Disruption to Homeowners

One of the most appealing aspects of reroofing over old shingles is the minimal disruption it causes to homeowners. Unlike a complete tear-off and replacement, which can involve the noise and mess of removing the old shingles, reroofing allows for a smoother and more convenient process. With reroofing, less noise and debris are generated, resulting in a more comfortable living environment for you and your family. This reduced disruption ensures that your daily activities and routines can continue with minimal interference.

The Cons of Reroofing Over Old Shingles

Additional Weight on the Roof Structure

One of the main concerns when reroofing over old shingles is the additional weight it adds to the roof structure. The new layer of shingles, along with the existing layer, can significantly increase the load on the roof. This can potentially exceed the weight limits that the roof was originally designed to bear. If the roof structure is unable to support the added weight, it can lead to structural issues such as sagging or even collapse. Therefore, it is crucial to consult with a structural engineer or a roofing professional to determine if your roof can safely accommodate the extra weight.

Hidden Damages

When reroofing over old shingles, there is a risk of overlooking hidden damages that may be present beneath the old shingles. Issues such as water damage, rot, or mold may not be visible until the old shingles are removed. Reroofing without properly addressing these underlying problems can lead to further deterioration of the roof structure and potentially compromise the new roofing system. It is essential to conduct a thorough inspection of the existing roof and address any damages before proceeding with the reroofing process.

Decreased Longevity of the New Roof

Reroofing over old shingles may result in a decreased longevity of the new roof compared to a complete tear-off and replacement. The underlying shingles can trap heat and moisture, which can accelerate the aging process of the new shingles. Over time, this can lead to premature wear and reduce the lifespan of the roof. Additionally, if the existing shingles are already nearing the end of their life expectancy, reroofing over them may only provide temporary relief and require a full replacement in the near future. Considering the long-term durability and lifespan of the new roof is important when deciding whether to reroof or opt for a complete replacement.

Potential Warranty Voidance

Reroofing over old shingles can also potentially void the warranty of the new roofing material. Many shingle manufacturers have specific guidelines and requirements for installation, including the need for a complete tear-off of the old shingles. Failing to follow these guidelines may result in the warranty being voided, leaving you responsible for any future repair or replacement costs. Before deciding to reroof, it is crucial to consult the warranty information provided by the manufacturer and make an informed decision regarding its potential impact.

Lack of New Technology and Upgraded Protection

Another downside of reroofing over old shingles is the lack of access to new technology and upgraded protection. Over the years, advancements in roofing materials and technologies have led to improved durability, energy efficiency, and protection against various environmental elements. If you choose to reroof, you may miss out on the opportunity to take advantage of these advancements and enhance the performance of your roofing system. It is important to consider whether the benefits of new technology outweigh the convenience and cost savings of reroofing.

Is It OK To Reroof Over Old Shingles?

Determining Factors for Reroofing Over Old Shingles

Condition of the Existing Roof

The condition of the existing roof is a crucial factor when considering reroofing over old shingles. If the old shingles are severely damaged, curled, or have missing pieces, reroofing may not be a viable option. Reroofing is best suited for roofs with shingles that are in relatively good condition and free from extensive damage. Conducting a thorough inspection or consulting with a professional roofer can help determine the overall condition of the existing roof and whether it is suitable for reroofing.

Number of Layers of Shingles

The number of layers of shingles already present on the roof is another important consideration. Building codes in some areas limit the number of layers allowed before a complete tear-off is required. Adding additional layers of shingles can place excessive weight on the roof structure and compromise its integrity. It is essential to check the local building codes and regulations to ensure compliance and determine the feasibility of reroofing.

Roofing Codes and Regulations

Understanding the roofing codes and regulations specific to your area is crucial when considering reroofing over old shingles. Each region may have its own requirements and guidelines regarding the installation and materials allowed for roofing. It is important to research and adhere to these codes to ensure compliance and the safety of your home. Consulting with a professional roofer familiar with the local codes and regulations can provide valuable insights and guidance in making informed decisions.

Roof Pitch

The roof pitch, or slope, is another factor that affects the feasibility of reroofing. Steep roofs with a high pitch may not be suitable for reroofing due to the added weight and difficulty of installation. Reroofing is generally more challenging on roofs with a steeper pitch, potentially resulting in a compromised installation or reduced performance of the new roofing system. Assessing the roof pitch and consulting with a professional roofer can help determine if reroofing is a viable option for your specific roof structure.

Personal Preferences and Future Plans

Personal preferences and future plans also play a role in the decision to reroof over old shingles. If preserving the aesthetic appearance of the existing roof is important to you, reroofing may be the preferred choice. Additionally, if you have plans to sell or renovate your home in the near future, reroofing can provide a cost-effective solution to improve the curb appeal and market value of the property. Considering your long-term goals and preferences can help guide your decision-making process.

Preparing the Roof for Reroofing

Thorough Inspection of the Existing Roof

Before proceeding with reroofing, it is crucial to conduct a thorough inspection of the existing roof. This inspection should assess the overall condition of the shingles, identify any damages or underlying issues, and determine if the roof structure can support the additional weight. It is recommended to hire a professional roofer to perform a comprehensive inspection as they have the expertise to identify potential problems that may not be immediately visible to an untrained eye.

Fixing Any Damages

If any damages are detected during the inspection, it is essential to address them before reroofing. Fixing any leaks, repairing damaged areas, and replacing rotted or deteriorated sections will help ensure the structural integrity of the roof and prevent further damage. Ignoring these issues can lead to more costly repairs in the future and compromise the effectiveness of the new roof. It is advisable to consult with a professional roofer for the necessary repairs and replacements to ensure proper and long-lasting solutions.

Clearing the Roof Surface

In preparation for reroofing, it is important to clear the roof surface of any debris, dirt, or loose shingle granules. This ensures a clean and smooth surface for the new shingles to be installed. The presence of debris can interfere with the proper adhesion and installation of the new shingles, potentially compromising their performance. Clearing the roof surface can be done through gentle brushing or using a leaf blower to remove loose materials.

Adding New Flashing if Necessary

Flashing plays a crucial role in preventing leaks and directing water away from vulnerable areas of the roof. During the roof preparation stage, it is essential to assess the condition of the existing flashing and determine if any replacements or additions are required. If the flashing is damaged, corroded, or missing, it should be replaced with new flashing to ensure proper waterproofing and protection. Adding new flashing as necessary will help enhance the overall performance and lifespan of the reroofing project.

Is It OK To Reroof Over Old Shingles?

Applying the New Shingles

Choosing the Right Shingles

Selecting the right shingles is an important step in the reroofing process. Consider factors such as material, color, style, and durability when choosing the new shingles. Each material option, such as asphalt, wood, metal, or synthetic, has its own unique characteristics and advantages. It is recommended to consult with a professional roofer or a trusted supplier to determine the best shingle option that suits your specific needs, budget, and aesthetic preferences.

Roof Deck Preparation

The roof deck, or the sheathing beneath the shingles, should be inspected and prepared before installing the new shingles. Any damaged or rotted sections should be replaced to ensure a solid foundation for the new roofing system. Additionally, the roof deck should be free from debris, protruding nails, and other obstacles that may interfere with the proper installation of the shingles. Proper roof deck preparation ensures the longevity and reliability of the new roof.

Installing the Starter Strip

To begin the shingle installation process, a starter strip should be installed along the eaves of the roof. The starter strip provides a secure base for the first row of shingles and helps prevent wind uplift. It is crucial to follow the manufacturer’s instructions and guidelines when installing the starter strip to ensure proper alignment and attachment.

Applying Shingles in Proper Overlapping Pattern

Once the starter strip is in place, the shingles can be installed in a proper overlapping pattern. Following the manufacturer’s instructions and guidelines, the shingles should be fastened securely to the roof deck using the recommended nails or fasteners. Proper alignment, overlap, and fastening are essential to create a watertight seal and ensure the overall integrity of the new roofing system. It is recommended to hire a professional roofer with experience in reroofing to ensure the correct installation technique and achieve optimal results.

Considerations for Hiring Professional Roofers

Licensed and Insured Roofing Contractor

When considering reroofing, it is highly recommended to hire a licensed and insured roofing contractor. A licensed contractor has met the necessary requirements and regulations set by the local authorities, ensuring their competence and professionalism. An insured contractor provides you with protection and peace of mind in case of any accidents or damages that may occur during the reroofing process. Checking the contractor’s license and insurance certificates before hiring them is essential for a successful and worry-free reroofing project.

Obtaining Necessary Permits

Before commencing any roofing work, it is important to check if any permits or approvals are required by the local authorities. Some areas may have specific regulations regarding roof replacements or modifications. The roofing contractor should be knowledgeable about the permit requirements and assist you in obtaining the necessary approvals. Failing to obtain the required permits can lead to legal issues and delays in completing the reroofing project.

Warranty and Guarantees

When hiring professional roofers for reroofing, it is essential to inquire about the warranties and guarantees they offer. A reputable roofing contractor should provide warranties on both labor and materials to ensure the quality and longevity of the new roof. Understanding the details and limitations of the warranties, such as the duration and coverage, will help you make an informed decision and protect your investment.

References and Reviews

Before finalizing your decision to hire a roofing contractor, it is advisable to check their references and reviews. Ask for references from previous clients who have undergone reroofing projects with the contractor and inquire about their overall experience and satisfaction. Additionally, read online reviews and ratings to gather insights into the contractor’s reputation and reliability. Taking the time to research and gather feedback will help you make an informed choice and select a contractor that meets your expectations.

Written Contract and Cost Estimate

To ensure transparency and avoid potential disputes, it is crucial to have a written contract and cost estimate in place before starting the reroofing project. The contract should clearly outline the scope of work, materials to be used, project timeline, payment terms, and any other relevant details. Review the contract thoroughly and make sure you understand and agree with all the terms before signing. The cost estimate should include a detailed breakdown of the project costs, allowing you to budget and plan accordingly.

Is It OK To Reroof Over Old Shingles?

Alternative Options to Reroofing Over Old Shingles

Complete Roof Tear-Off and Replacement

While reroofing over old shingles can offer advantages, it is important to consider the alternative option of a complete roof tear-off and replacement. A complete replacement provides an opportunity to address any underlying issues, replace damaged or outdated materials, and start fresh with a new roofing system. Although it may involve a higher upfront cost and longer installation time, a complete tear-off can provide peace of mind and ensure the best long-term performance and durability of your roof.

Roof Coating and Restoration

Another alternative to reroofing over old shingles is roof coating and restoration. Roof coating involves applying a protective layer over the existing shingles to extend their lifespan and enhance their performance. It can provide added weather resistance, energy efficiency, and protection against UV rays. However, roof coating is only suitable for roofs with shingles in good condition and minimal damage. Restoration options, such as roof cleaning, sealing, and repair, can also help rejuvenate the existing roof and improve its appearance and functionality.


Reroofing over old shingles can offer time and cost savings, reduced environmental impact, and the preservation of existing roofing material. However, it is important to consider the potential drawbacks, such as additional weight on the roof structure, hidden damages, decreased longevity of the new roof, potential warranty voidance, and lack of access to new technology and upgraded protection. Determining factors for reroofing include the condition of the existing roof, number of layers of shingles, roofing codes and regulations, roof pitch, personal preferences, and future plans. Proper preparation of the roof, including a thorough inspection, fixing damages, clearing the roof surface, and adding new flashing if necessary, is essential for a successful reroofing project. When hiring professional roofers, ensure they are licensed and insured, obtain necessary permits, inquire about warranties and guarantees, check references and reviews, and have a written contract and cost estimate. Lastly, consider the alternative options of a complete roof tear-off and replacement or roof coating and restoration. Ultimately, the decision to reroof over old shingles should be based on careful consideration of the pros and cons, as well as your specific needs and circumstances.

Is It OK To Reroof Over Old Shingles?

Scroll to Top