If your roof is leaking and you’re not sure how old it is, you may be worried that your entire roofing system will have to be replaced. However, not all roof leaks require a complete replacement to resolve. But when should you replace your roof?

The answer to that question will be different for everyone and can be determined by a number of different factors. Knowing what to look for is the first step in making an informed decision on repair versus replacement. Here are a few things to look for when determining whether you need a new roof:


Cracks and splits are one of the most common issues your asphalt shingle roofing system can face. When not addressed, cracks and splits in your shingles can expose your roof’s sheathing to water damage and leave your home vulnerable to leaks.


Strong winds or heavy storms can cause your shingles to become detached and blow off of the roof deck. These missing shingles can lead to sheathing damage and leaks in the interior of your home or business.

Other wind damage to your roof may not be as easy to see. If you see evidence of thin horizontal lines where the granules have worn off one to two inches beneath the shingle above it, it indicates that the shingle seal is broken and the shingle has been flapping in the wind. To effectively shed water and protect your home or business from the elements, shingles must be sealed tightly against one another as a single watertight system.


It’s usually pretty hard to miss a hail storm, as they are typically widespread weather events not isolated to a single house or block in your neighborhood. When hail strikes your roof shingles, the impact can “bruise” the shingle mat and leave an indentation. While these indentations can sometimes be hard to see, they’re actually cracks in your shingles that can allow water to infiltrate into your home or business over time. We always recommend calling a professional roofing contractor like Trenton Roofing & Siding for thorough and accurate hail damage assessments.


It’s important to distinguish a clear difference between moss and algae when it comes to how they affect your roof. Algae, also commonly called “mold’ or “mildew”, is a type of photosynthetic organic growth that leaves ugly black or brown streaks on your roof and stains your shingles over time.

Moss, a plant with leaves that usually grows in thick clumps, can be far more damaging to your roofing system. A thick growth of moss essentially acts as a sponge for rainfall which can keep your roof damp for long periods of time while degrading your shingles and roof sheathing. It can also push up the edges of your shingles, leaving them more vulnerable to blowoffs.


Temperature fluctuations causes your roof sheathing to expand and contract, which eventually works nails out of the wood decking over time. As they rise out of the sheathing, these nails push up the shingle above it which can crack or displace the shingle. Often called “nail pops”, these incidents are perhaps the most common cause of all roof leaks.


Long-term, uniform granule loss is part of the natural aging process of your roofing system. The rate at which shingles lose their granules depends on the quality of your shingles as well as the climate of region they’re installed in.

Over time, the bond between the granules and the asphalt deteriorates, which loosens the granules and allows them to be carried away by runoff. This granule loss can mitigate your roofing system’s ability to effectively shed water and lead to interior leaks once too many granules are lost.


Your roof’s sheathing is an important part of your roofing system. Sheathing (also called “decking”), usually made from plywood or particle board, can be susceptible to damage when continuously exposed to excess moisture.

Attic inspections are the easiest way to determine if your roofing system has been compromised by any sheathing damage. It’s always best to have a professional roofing contractor like Trenton Roofing & Siding perform a thorough inspection of the attic to determine the condition of the sheathing of your home or business.


If your home or business has a chimney, you may have damaged flashing. Chimney flashing is a type of roof flashing that creates a waterproof seal between your chimney and roof shingles to prevent water penetration into your home or business. If the flashing around your chimney fails, it can cause serious internal leaks as well as masonry damage to the chimney itself.


Standard three-tab asphalt shingle roofs were designed to last twenty-five years, but typically fail prematurely around twenty to twenty-four years. Any trustworthy and reputable roofing contractor such as Trenton Roofing & Siding will recommend that you replace your roof at approximately eighty percent of its intended lifespan. For three-tab asphalt shingle roofs, that’s right around twenty years.

If you’re experiencing any of the above problems with your roofing system while it’s less than fifteen years old, it’s recommended to look into spot repair solutions. However, if you’re experiencing any of these roofing issues with your home or business and the roofing system is approximately twenty years old, it may be time for a full replacement.

Either way, it’s best to call a reliable roofing contractor like Trenton Roofing & Siding for accurate and reliable assessments of your roofing system. From there, one of our customer-focused Sales Project Managers will recommend a solution uniquely tailored to your project. Give us a call today for a free estimate!

Alex Valentino

Alex Valentino – Vice President

Leading the way for the company’s second generation of family and employee ownership, Alex’s mission is to create lasting relationships built on trust and respect by providing uncompromising workmanship and unparalleled customer service. With a focus on safety and consumer education, Trenton Roofing strives to set the bar for the advancement of the roofing industry and the betterment of our local communities. When he is not working, Alex can be found traveling with his fiancée, watching football or playing a relaxing round of golf with his friends.