Roofing over existing shingles, often referred to as a re-roof, can be a tempting option for homeowners looking to save on costs and time. However, whether this is a viable option depends on various factors such as the condition of the current roof, local building codes, and the weight capacity of your home’s structure. In this comprehensive 1500-word guide, we’ll explore the considerations, benefits, and potential drawbacks of roofing over existing shingles.

Understanding the Basics of Re-Roofing

Re-roofing involves installing a new layer of shingles over the existing one. This method can only be considered if there’s just one layer of shingles in place. Most building codes prohibit more than two layers of roofing material for safety and structural reasons.

Evaluating the Condition of Your Current Roof

Before deciding on re-roofing, a thorough inspection of the existing shingles and roof structure is crucial. Here are key points to consider:

Age of Existing Shingles: If the shingles are near the end of their lifespan, it’s better to replace them.

Extent of Damage: Look for extensive damage, such as large areas of missing shingles, significant curling, or loss of granules.

Leaks and Water Damage: Check for signs of leaks or water damage in the attic. If these issues are widespread, a complete roof replacement is advisable.

Pros and Cons of Roofing Over Existing Shingles


Cost-Effective: It’s generally less expensive in terms of labor and materials since you’re avoiding the cost of removing the old shingles.

Time-Saving: The process is faster as it skips the tear-off phase.

Convenience: Less mess and disruption since you’re not tearing off the old roof.


Shorter Lifespan: A re-roof might not last as long as a complete replacement because of potential issues hidden beneath the old shingles.

Hidden Damage: It’s difficult to inspect and repair the underlayment, decking, or any structural damage with the old shingles in place.

Additional Weight: Extra layers add weight to your roof structure, which could be a problem if your home isn’t structurally equipped to handle it.

Warranty Issues: Some manufacturers may not honor the warranty for shingles installed over existing layers.

Local Building Codes and Regulations

Before proceeding, check with your local building department. Most areas have specific regulations about how many layers of roofing are allowed. Adhering to these codes is essential for the safety and legality of the project.

Considerations for Roofing Material

If you decide to re-roof, consider the type of shingles you’re using. Heavier materials like architectural shingles may not be suitable for layering over older shingles.

Professional Roof Inspection

A professional roofer can assess the condition of your current roof and provide recommendations. They can also check for ventilation issues, which are crucial in maintaining the longevity of your new roof.

Weighing the Long-Term Impact

While re-roofing can be more affordable upfront, it may be more costly in the long run. If issues arise later, you’ll be facing the cost of removing two layers of shingles instead of one.

Installation Quality

The quality of installation is a critical factor. Poor installation can lead to premature failures, leaks, and other issues. Ensure that you hire a reputable and experienced contractor for the job.

Impact on Resale Value

Consider the impact on your home’s resale value. A new roof can be a selling point, while a re-roof might raise concerns for potential buyers about underlying issues.

Environmental Considerations

Roof removal contributes to waste in landfills. By re-roofing, you’re reducing waste, which could be an environmentally friendly option if your current roof is in relatively good condition.

Warranty and Insurance Considerations

Check the warranty terms of the new roofing material. Some manufacturers may offer limited or no warranty for shingles installed over existing ones. Additionally, consult with your home insurance provider to understand how re-roofing might affect your coverage.

Preparing for Re-Roofing

If you choose to re-roof, preparation is key:

Roof Cleaning: Clean the existing roof surface to ensure the new shingles adhere properly.

Inspection of Roof Features: Check flashings, vents, and chimneys. These may need to be replaced or adjusted.

Decking Inspection: While it’s difficult to inspect the decking thoroughly, look for visible signs of rot or damage around the edges or in the attic.

Hiring a Professional Roofing Contractor

Selecting a qualified roofing contractor is vital. Look for licensed and insured local roofers with experience in re-roofing. They can provide a detailed assessment and ensure that the project complies with local codes and manufacturer specifications.

Making an Informed Decision

Ultimately, the decision to roof over existing shingles should be based on a careful assessment of your current roof’s condition, budget considerations, long-term planning, and professional advice. In some cases, re-roofing can be a viable, cost-effective solution, especially if the existing roof is in relatively good condition. In other scenarios, especially where there is significant damage or aging, a complete roof replacement might be the more prudent choice.

In conclusion, deciding whether to re-roof over existing shingles or opt for a complete roof replacement involves several factors. It’s a balance between immediate cost savings and the long-term health of your roofing system. Conducting a thorough inspection, understanding the pros and cons, complying with local building codes, and consulting with professional roofers are all crucial steps in making the right choice for your home. Whether you’re considering residential or commercial roofing, an informed approach will help ensure the longevity, safety, and efficiency of your roofing investment.