Can You Roof Over Existing Shingles?
When it’s time for a new roof, many homeowners wonder if they can save money by installing new shingles directly over the old ones. This process, known as a roof overlay or re-roofing, can be a viable option in rare cases — but it’s not always the best choice. Here’s what you need to know before deciding whether to roof over your existing shingles.
The Basics of Roofing Over Shingles
Instead of tearing off the old shingles and starting from bare roof decking, a roofing crew installs the new shingles directly on top of the existing layer. This approach can reduce labor time, minimize disposal costs, and complete the job more efficiently.
Advantages of Roofing Over Existing Shingles
- Lower Cost – Skipping the tear-off process saves on labor and landfill fees, making the project more affordable.
- Faster Installation – Without the removal step, most overlays can be completed more quickly.
- Less Mess – Fewer materials are removed from the roof, meaning less debris in your yard during the project.
Drawbacks and Considerations
While it sounds appealing, roofing over existing shingles isn’t always a wise decision. Potential issues include:
- Hidden Damage – A tear-off allows your roofer to inspect the roof decking for rot, mold, or water damage. If you skip this step, problems can go undetected and worsen over time.
- Added Weight – Shingles are heavy. Adding a second layer increases the load on your roof structure, which can be risky, especially on older homes.
- Shorter Lifespan – A roof overlay often doesn’t last as long as a completely new roof because the underlying shingles can trap heat, causing the new ones to age prematurely.
- Uneven Surface – If your current shingles are curled, cracked, or bumpy, the new layer may not lie flat, leading to aesthetic and performance issues.
- Building Code Restrictions – Many municipalities limit the number of shingle layers allowed (often two). Some require a complete tear-off before installing new roofing material.
When Roofing Over Shingles Might Work
Overlaying can be a reasonable option if:
The following factors are only valid when a Stone Coated Steel roofing product is being installed
- Your existing roof has only one layer of shingles.
- The current shingles are in relatively good shape (no severe curling, buckling, or missing areas).
- The roof decking and structure are in good condition, with no visible signs of water damage.
- Local building codes allow it.
When a Tear-Off Is the Better Choice
A complete tear-off is usually the best route if:
Always, except when a Stone Coated roof is going back on
- There are already two layers of roofing.
- You’ve experienced leaks or structural problems.
- You plan to live in the home long-term and want the longest-lasting roof possible.
Bottom line: Yes, you can roof over existing shingles in certain situations, but it’s not always the best option. While it can save money upfront, the potential downsides — from hidden damage to reduced lifespan — often make a complete tear-off the smarter long-term investment. The best way to decide is to have a licensed roofing contractor inspect your current roof, evaluate its condition, and discuss the pros and cons based on your specific home.
