Roofing is a critical aspect of home maintenance, and the decision to add a new layer of shingles over an existing one is a topic of much debate. At Benson Contracting, located in Glens Falls, NY, we understand the intricacies of roofing and are here to provide a detailed analysis of the pros and cons of double-layer shingle roofing.

Advantages of Double Layer Shingles


One of the primary advantages of installing a second layer of shingles over the existing one is the potential cost savings. This method eliminates the need for a complete tear-off, thereby reducing labor and disposal costs. The absence of a tear-off process means less time and resources are spent on removing old shingles and cleaning up, which can translate into lower overall project costs.

Time Efficiency

Adding a new layer of shingles over an existing one is generally a quicker process than a complete roof replacement. This is particularly beneficial when time constraints are a factor, such as in emergency repair situations or when weather conditions demand a speedy solution.

Reduced Environmental Impact

By avoiding the removal of the existing shingle layer, there is a significant reduction in waste generation. This approach is more environmentally friendly as it minimizes the amount of roofing material that ends up in landfills.

Disadvantages of Double Layer Shingles

Compromised Roof Integrity

The additional weight of a second layer of shingles can put extra stress on the roof structure. This is especially concerning in areas with heavy snowfall, where the combined weight of snow and multiple shingle layers could exceed the load-bearing capacity of the roof.

Shortened Lifespan

The lifespan of the second layer of shingles is often reduced due to factors like heat absorption and potential moisture entrapment between layers. This can lead to quicker deterioration, warping, and the need for more frequent repairs or replacement.

Warranty and Code Compliance Issues

Many shingle manufacturers void warranties if their products are installed over an existing layer of shingles. Additionally, building codes in some regions may restrict or prohibit double-layer shingling, making it essential to verify local regulations before proceeding with such an installation.

Challenges in Leak Detection and Repair

Identifying and repairing leaks can be more challenging in a double-layered roof. Water can travel unpredictably between layers, making it difficult to locate the source of a leak. Repairs may require stripping both layers, adding complexity and cost to the process.

Aesthetic Considerations

A second layer of shingles may not lie as flat or look as uniform as a single layer. This