Should you Remove Shingles before Installing a Metal roof?

When it’s time to upgrade your home’s roof, deciding whether to remove shingles or leave them in place is a big decision. This choice affects everything from cost and labor to long-term durability and energy efficiency. Let’s explore the pros, cons, and expert recommendations to help you make an informed decision.

Keeping Shingles in Place: The Pros and Cons

Benefits of Installing a Metal Roof Over Shingles

1. Cost and Time Savings
   By keeping the existing asphalt shingles, you save on labor costs for removal and disposal. This approach also reduces waste, making it an eco-friendly option. Additionally, it’s a faster process, especially during seasons with unexpected storms or tight schedules.
2. Added Insulation
   Shingles act as an extra layer of protection, improving thermal insulation. They help regulate temperature during hot summers and cold winters, reducing heating and cooling expenses. For homeowners aiming to lower their energy bills, this can be a financially sound approach.
3. Reduced Debris
   Removing shingles creates a messy job, with crumbly, black, and dusty debris. Installing over existing shingles minimizes cleanup and waste, reducing landfill impact. It’s a sustainable practice for the environmentally conscious homeowner.
4. Snow-shedding and Noise Reduction
   Metal roofs are excellent for snow-shedding and reducing noise from rain and hailstorms, especially when installed over a thicker base. The shingles underneath create a buffer, dampening sound for a quieter indoor experience.

Drawbacks of Leaving Shingles

1. Risk of Hidden Damage
   If the roof deck underneath the shingles has cracks, rot, or deterioration, leaving the shingles in place can worsen the issues over time. These structural risks can shorten the lifespan of the new roof and compromise its integrity.
2. Uneven Surface
   Warped or bumpy shingles can prevent the metal panels from sitting flat. This affects both the aesthetics and functionality of the new roof, leading to potential gaps and poor sealing.
3. Moisture Trapping
   Layers of shingles can trap moisture, especially if proper ventilation is lacking. Over time, this can cause mold, rot, and other pest-related issues, damaging the entire roofing structure.
4. Weight Concerns
   Adding a metal roof over existing shingles increases the overall weight on the rafters and beams. Older or poorly constructed homes may struggle to bear the additional load, risking structural collapse during heavy snowstorms or high winds.

Removing Shingles: Why It’s Often Recommended

Advantages of Shingle Removal

1. Thorough Inspection and Repairs
   Removing shingles allows for a detailed inspection of the decking and underlayment. Any issues, such as rotted wood, gaps, or cracks, can be repaired to provide a smooth, solid base for the new metal roof. This ensures long-term durability and structural integrity.
2. Improved Fit and Finish
   A clean surface ensures that the metal panels lay neat and secure, eliminating the risk of warped sections or uneven seams. This improves the overall look and performance of the roof, boosting your home’s aesthetic value.
3. Building Code Compliance
   Many local codes restrict the number of roofing layers allowed. Removing shingles ensures compliance and prevents issues during future inspections or insurance claims. Some manufacturers even void warranties if installation guidelines are not followed.
4. Enhanced Longevity
   Without the risk of underlying moisture or pests, a metal roof installed on a clean deck is more likely to last its full lifetime. It also eliminates the chance of fasteners loosening due to improper installation over uneven surfaces.

Key Considerations Before Deciding

• Climate and Weather
  In areas prone to snow, hailstorms, or heavy rainfall, a properly prepped roof with water barriers and solid decking is crucial for preventing leaks and ensuring proper protection.
• Cost vs. Investment
  While removing shingles increases upfront costs, it offers a better long-term investment by extending the lifespan of your metal roof. Calculate whether the added price aligns with your financial preferences.
• Ventilation and Insulation
  Proper ventilation is critical to prevent moisture buildup. A poorly vented roof risks trapped air, leading to mold or rot. Ensure your contractor uses high-quality underlayment and considers air circulation during installation.
• Roof Structure and Weight
  Assess the condition of your rafters and decking. If your home’s structure isn’t designed for additional weight, removing the shingles is safer and prevents future structural risks.

Our Recommendation

We suggest removing old shingles before installing a metal roof. This allows for proper preparation, ensures compliance with building standards, and creates a clean foundation for the new roof. However, if your existing shingles are in good condition and you’re working within a tight budget, installing over them can still be an efficient option—with certain precautions.

For homeowners unsure of the best route, a professional inspection is vital. Reliable roofers can assess the condition of your current roof and offer tailored guidance, helping you avoid common mistakes and make the best choices for your home.

Whether you remove shingles or not depends on your home’s structure, budget, and personal preferences. While keeping shingles may save on labor and reduce waste, removing them ensures a long-lasting, high-quality, and problem-free installation. Carefully weigh the pros and cons, consult with experts, and prioritize proper prep for a roof that’s built to last.

By planning ahead and considering all factors, you’ll make an informed decision that protects your home, enhances its value, and delivers peace of mind for years to come.