How Do You Identify Two Layers of Shingles on a Roof?

Many homeowners may not realize that their roof has two layers of shingles until issues arise. While adding a second layer of shingles might seem like a cost-effective solution to a roof replacement, it often leads to hidden problems that can compromise the longevity and safety of the structure.

In this article, we’ll cover:

• How to identify two layers of shingles on a roof
• The issues that come with multiple layers
• Why removing old shingles before re-roofing is the best practice

How Do You Identify Two Layers of Shingles on a Roof?

Before purchasing a home or scheduling a roof replacement, it’s crucial to determine whether there are multiple layers of shingles. Here’s how you can identify a double-layered roof:

1. Check the Roof’s Edge

Stand back and inspect the edges of your roof. If you see a second layer of shingles sticking out from underneath the top layer, that’s a clear sign of multiple layers.

2. Inspect the Roof Surface

Walk around your home and look for uneven or wavy areas on the roof. Multiple layers of shingles can create an irregular surface since the new layer conforms to the shape of the old shingles.

3. Look Inside the Attic

Go into your attic and inspect the underside of the roof deck. If you see extra thickness along the roofline or nails that appear too short (because they don’t fully penetrate the decking), there may be a second layer of shingles.

4. Ask a Roofing Contractor

A professional roofing contractor can inspect your roof and confirm whether multiple layers exist. They can also assess whether the extra layer is causing problems.

What Issues Come with Two Shingle Layers on a Roof?

While layering shingles can save money upfront, it often creates long-term complications. Here’s why:

1. Problems with the Old Shingles Didn’t Go Away

When a second layer of shingles is installed, the underlying issues with the old shingles don’t disappear. If there was already curling, cracking, or moisture damage, those problems remain and can worsen over time.

2. Leaks Are Harder to Track and Repair

A two-layered roof makes leak detection difficult because water can travel between the layers before becoming visible. This can lead to extensive interior damage before the problem is discovered.

3. Two Shingle Layers Are Heavy

A single layer of asphalt shingles already adds significant weight to a roof. Doubling that weight puts extra stress on the roof deck and structure, increasing the risk of sagging or failure over time.

Why Removing Old Shingles Is the Best Practice

Instead of adding a second layer of shingles, it’s always best to remove the old shingles before installing a new roof. Here’s why:

• Better Inspection – Removing old shingles allows for a full inspection of the roof deck, identifying and fixing underlying problems.
• Longer Lifespan – A single-layered roof lasts longer because it provides a better foundation for new shingles.
• Manufacturer Warranty Compliance – Many roofing material warranties require a single-layer installation to remain valid.

Work with a Professional Roofing Contractor

At S&K Construction and Remodeling LLC, we prioritize quality roofing solutions for homeowners in Northeast Ohio. As an Owens Corning Preferred Contractor, we follow best practices to ensure your roof is built to last.

If you suspect your roof has multiple layers or need a professional inspection, contact us today for expert guidance and a free consultation!