Pros and Cons of Roofing Over Existing Shingles: Why a Complete Tear-Off is Recommended


When considering a new roofing project, one option that may seem enticing is roofing over existing shingles. While this approach can offer time and cost savings, it’s crucial to understand its potential drawbacks. In this blog post, we will thoroughly explore the pros and cons of roofing over existing shingles, and ultimately recommend why a complete tear-off is the preferred choice for a long-lasting and durable roofing system.

Pros of Roofing Over Existing Shingles:

Time and Cost Savings:

Roofing over existing shingles can be quicker and more cost-effective than a complete tear-off. It eliminates the need to remove the old shingles and dispose of them, reducing labor and disposal costs.

Temporary Aesthetics Improvement:

Roofing over existing shingles may provide a temporary improvement to the appearance of your roof, especially if the old shingles are worn or discolored. It can offer a quick fix to enhance curb appeal.

Minimal Disruption:

Roofing over existing shingles creates less disruption to your daily life during the installation process. It can shorten the time your home is exposed to the elements during construction.

Cons of Roofing Over Existing Shingles:

Reduced Roof Lifespan:

Roofing over existing shingles can shorten the lifespan of the new roof. It doesn’t address underlying issues with the old shingles, and any pre-existing problems may persist and worsen over time.

Trapped Moisture and Heat:

Adding another layer of shingles can trap moisture and heat between the old and new layers, leading to premature deterioration and potential rot. This trapped moisture can also promote mold growth, further damaging the roof structure.

Concealing Underlying Problems:

Roofing over existing shingles can mask underlying problems such as damaged decking or compromised flashing. This makes it difficult to detect and address issues that could affect the structural integrity of the roof.

Weight Concerns:

Installing multiple layers of shingles can add significant weight to the roof structure. This can exceed the roof’s load-bearing capacity, leading to sagging and potential structural damage.

Expert Recommendation: Complete Tear-Off is the Best Choice

Rain City Exteriors recommends a complete tear-off and replacement of the existing shingles for the following reasons:

Long-Term Durability:

A complete tear-off allows for a thorough inspection of the roof’s decking and structural components. Any damaged or weakened areas can be addressed, ensuring a solid foundation for the new roofing system. This approach provides the best chance of a long-lasting and durable roof.

Optimal Installation:

Roofing over existing shingles can result in uneven surfaces and improper adhesion of the new shingles. A complete tear-off ensures a clean slate for the installation of the new roofing materials, providing a seamless and watertight finish.

Preventing Future Issues:

Addressing underlying problems with a complete tear-off helps prevent future issues and costly repairs. It allows Rain City Exteriors to identify and fix potential sources of leaks or damage, providing homeowners with peace of mind and long-term protection.


While roofing over existing shingles may offer initial cost and time savings, it comes with significant drawbacks that can compromise the longevity and performance of your new roof. For the best results and long-term durability, Rain City Exteriors recommends a complete tear-off and replacement of the existing shingles. This approach ensures a properly installed, reliable, and durable roofing system that will protect your home for years to come. Contact Rain City Exteriors for a professional assessment and expert installation tailored to your specific roofing needs.

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