If your roof is showing signs of wear, you may be considering new shingles. That opens up a couple of options, including reroofing with a full tear-off. However, you may also ask: Can you reroof over existing shingles? It’s a common question for South Jersey homeowners—and a decision that can save money and time if done correctly. But is it always a good idea? Homeowners such as yourself should be armed with knowledge to make informed roofing decisions. That’s why, in this article, we’re going to walk you through the benefits and drawbacks of reroofing over existing shingles, when it’s allowed under New Jersey building codes, and how to tell if your home qualifies.
Key Takeaways
- Reroofing over existing shingles is a legal and potentially cost-saving option in New Jersey, but only if there is a single existing layer and the roof is in good condition.
- Pros include lower upfront costs, quicker installation, and less mess compared to a full tear-off roof replacement.
- Cons include the risk of hidden damage, a shorter lifespan for the new shingles, and added weight on your home’s structure.
- New Jersey building codes allow only two total layers of asphalt shingles and require the underlying roof to be structurally sound and properly flashed.
- Reroofing may be suitable for short-term homeowners with minimal roof wear, but a full tear-off is often the better long-term solution—especially if you want warranty protection or plan to stay in your home.
What Does It Mean to Reroof Over Existing Shingles?
To reroof over existing shingles means adding a new layer of asphalt shingles on top of your current roof without removing the original layer. This is sometimes called a “layover” or a “recover,” and it’s legal in New Jersey under certain conditions—mainly if there’s only one existing layer of shingles and the structure is in good condition.
Pros of Reroofing Over Existing Shingles
Let’s take a look at the advantages of reroofing over a layer of shingles:
1. Lower Upfront Cost
One of the biggest reasons homeowners consider a roof overlay is cost savings. Reroofing eliminates the need for tearing off and disposing of the old shingles, which significantly reduces labor and dumpster fees. This can make it an appealing option for homeowners working within a tighter budget or those looking to boost curb appeal before selling a home. While it doesn’t address every underlying issue, it offers a faster way to restore the appearance and weather resistance of your roof.
2. Faster Installation
Because there’s no tear-off process, the overall project timeline is much shorter. Most reroofing jobs can be completed in one to two days, depending on the size of the home and weather conditions. This is particularly advantageous for homeowners who want to minimize disruption or are facing an urgent need for roof improvements, such as pending bad weather or preparing for a home appraisal.
3. Less Mess Around Your Home
Traditional roof replacements generate a lot of debris—shingles, nails, underlayment, and damaged wood all need to be removed and hauled away. With reroofing, there’s little to no mess around your property. This is a welcome benefit for families with children, pets, or limited space, and it helps reduce the risk of injury from stray nails or construction materials left behind in the yard.
Cons of Reroofing Over Shingles
Now consider the disadvantages:
1. Hidden Damage Isn’t Repaired
One major drawback of an overlay is that your contractor cannot thoroughly inspect the roof deck beneath the old shingles. If there’s soft, sagging wood, trapped moisture, or evidence of mold, it will remain hidden under the new layer. Over time, that damage can worsen and lead to leaks, structural problems, and the need for a full tear-off anyway. Without addressing these underlying issues, you risk paying more in the long run.
2. Shorter Lifespan of New Shingles
When new shingles are installed over an uneven, cracked, or deteriorating surface, they are more likely to warp, lift, or wear prematurely. Poor ventilation, reduced heat dissipation, and inconsistent adhesion all contribute to a shortened roof lifespan. Many shingle manufacturers may void their warranty if the product is installed over an existing roof, which could leave homeowners without protection if problems arise later.
3. Heavier Load on Your Structure
Asphalt shingles are lightweight, but layering a second roof adds hundreds of extra pounds to your home’s structure. If your roof trusses, rafters, or decking are not in excellent condition, that added weight can cause sagging or even structural stress over time. This is especially concerning for older homes or those already dealing with minor settling or foundation issues. Before any overlay project, it’s essential to have your roof structure evaluated by a licensed contractor.
What Do New Jersey Building Codes Say About Reroofing Over Existing Shingles?
The New Jersey Administrative Code (NJAC 5:23) and local building departments follow the International Residential Code (IRC). Here are the key reroofing rules:
- No more than two layers of asphalt shingles are allowed. If your home already has two layers, you must tear off both before reroofing.
- The existing roof must be in good condition. If the current shingles are curling, lifting, or damaged—or if the roof deck is rotted—a layover is not allowed.
- Proper flashing must still be installed. Flashing at valleys, chimneys, vents, and eaves must function properly, even with a second layer.
- Inspection is required. Some municipalities require permits and inspections even for overlay roofing. Always check with your local building office or consult a licensed contractor like RGB Construction.
When is Reroofing a Smart Option?
Although placing shingles over an existing set of shingles is generally not recommended by roofers in New Jersey, there are some scenarios where it makes sense. Reroofing may be good option if your existing roof:
- Has a single layer of shingles
- Shows no signs of leaks or rot
- Has a relatively flat or even surface
- Is nearing the end of its life, but you plan on moving soon
In any of these cases, reroofing over existing shingles can extend the life of your roof by 10 to 15 years while reducing the overall cost.
Now, when should you avoid reroofing over existing shingles? Avoid if your roof has more than two layers of shingles, as that’s a code violation. Also avoid reroofing if you’ve experienced recent leaks or sagging, you plan on staying in your home long-term, or if you want a full manufacturer warranty.
Schedule Your Reroofing Today with Trusted Roofing Contractor, RGB Construction
While reroofing over existing shingles can save time and money, it’s not always the best option. Choosing the right approach requires understanding your roof’s current condition, code compliance, and long-term goals. At RGB Construction, we strongly advise South Jersey homeowners to schedule a roof inspection before considering reroofing over existing shingles. Our licensed team examines your existing materials, decking integrity, and attic ventilation to determine whether a layover will work—or if it could cause more problems down the road.
Have questions about reroofing in Gloucester, Camden, or Burlington County? Contact RGB Construction for a detailed inspection and honest guidance, because your roof deserves more than a shortcut. Reach us at 856-264-9093 or by filling out the contact form.
