The Truth About Layering New Shingles Over Old Ones: An Expert Perspective
section-1bd99f8
Why Homeowners Consider Layering Shingles
The idea of layering new shingles over old ones is often appealing to homeowners for two main reasons:
- Cost Efficiency: On average, you can save around 15% of the total roofing cost, which translates to approximately $1 per square foot of roof.
- Time-Saving: Skipping the tear-off process can save up to 30% of the job site time, allowing the roofing crew to start installing new shingles immediately.
section-a200a71

The Risks of Layering Shingles: What You Need to Know
Roof Deck and Underlayment Inspection
When you opt for layering shingles, the roof deck and underlayment go unchecked. These are crucial elements that provide extra protection to your home's interior. Without tearing off the existing shingles, it's impossible to identify potential issues like rotting spots in the roof decking or deteriorated underlayment.
Bacterial Growth
Layering shingles can trap existing algae or moss, which can adversely affect the lifespan of your new shingles.
Structural Weight Concerns
A single square of roofing weighs between 250-400 pounds. Doubling that weight puts significant stress on your home's structural integrity, potentially worsening any existing damage to the sheathing and affecting ventilation and insulation.
Installation Challenges
Shingles are designed to be nailed into a flat surface. Layering them over existing shingles can compromise the integrity of the installation, increasing the likelihood of shingles blowing off due to uneven surfaces.
Warranty Issues
Many shingle manufacturers void warranties if a second layer of shingles is added.
Future Tear-Off Requirements
Most building codes limit roofing layers to two. When it's time for another roof replacement, you'll have to pay extra for tearing off both layers.
Impact on Home Resale
Home inspectors often flag double-layer roofs, which can deter potential buyers.
Alternatives to Asphalt Shingles
If you're considering other materials, metal roofing can be a viable option. It offers long-term benefits and doesn't require tearing off existing shingles, provided they are in good condition.
Consult with Equity Roofing: Your Trusted Central PA Roofers
Before making a final decision, it's crucial to consult with experts. At Equity Roofing, we offer top-notch Central PA roofing services. Allow us to conduct an inspection to determine the best course of action for your roofing needs.
Ready to Take the Next Step?
We at Equity Roofing are excited to discuss your roofing options. As one of the leading roofing companies in Central Pennsylvania, we prioritize the longevity of your roof and the security of your home. Contact us today to explore the best solutions tailored to your needs.
Read also our blog on The Optimal Season for Roof Replacement: A Detailed Analysis by Equity Roofing.
section-9039897
Contact us
-
256 Chestnut Street Mifflinburg, PA 17844
-
(570) 218-5683
-
sales@equityroofs.com