How Old Is Your Roof? 5 Ways To Tell

Knowing the age of your home’s roof is an invaluable piece of information. Your roof protects your home’s uppermost level from the weather and invasive pests. Old roofs are prone to leaks, gaps, and in extreme cases, collapses. Roof replacements are expensive investments, with the costs ranging from $5,000 to $11,000, with the national average at around $8,000.

Knowing the roof’s age allows you to plan your expenses and prepare for the eventual replacement you will have to undergo. Unfortunately, determining the age of your roof can be tricky, but in this guide, we will go over some telltale signs of an aging roof. 

How Long Does a Roof Last? 

Several factors determine a roof’s functional age. Keep these factors in mind when purchasing a roof replacement and when looking at the roof of a house that you’re interested in buying. These factors can even make new roofs deteriorate faster than expected.

• Workmanship: The quality of workmanship in a roof installation can significantly impact its life span. Misaligned shingles, gaps, and incorrectly installed underlayment can result in leaks and moisture buildup, wearing down your roof over time. 
• Underlayment: Underlayment is a layer of waterproofing underneath the shingles and sheathing. It functions as a second layer of protection from the elements if the shingles and upper layers become damaged. Incorrectly installed or damaged underlayment can lead to trapped moisture and mold buildup inside your home. 
• Regional weather: Certain regions like the Midwest and coastlines have weather that can adversely affect roofs and shorten their expected life spans. 
• Roof and attic ventilation: Poor roof and attic ventilation can result in overly hot roofs. This increase in temperature leads to a shortening of the life span of shingles and other problems like ice dams, swelling, moisture buildup, and even rot.  

The most significant factor in the roof’s life span is its materials. Generally speaking, the higher a material’s quality, the greater the roof’s life span and the higher the installation cost. What follows is a short list of the most commonly available roofing materials.  

Asphalt and Shingle Roofs

These are the most common roofing materials out there. Most homes in America use basic asphalt shingles due to their ease of installation and low cost. However, even in ideal conditions, these shingles have the lowest life span, only 15-20 years. 

Wood Shingles

Wood shingles are more resistant to wind and generally more durable than asphalt shingles. These shingles are reasonably priced for the amount of durability they provide but require more regular upkeep and maintenance. You will need to apply protective treatments once every three years, including fungicides, fire and water repellents, and algicides. Failure to apply these regular treatments can leave the wood susceptible to termites, mold and mildew growth, increased fire risk, bending, warping, and buckling. If properly maintained, wood shingles can last up to 30 years, depending on the wood and surrounding weather. 

Metal 

Metal roofs have grown more popular recently due to their sustainability and pleasing aesthetic. While slightly more expensive than wooden and asphalt roofs, metal roofs will last longer and require less maintenance. Furthermore, metal thickness and quality go a long way with metal roofs, with thicker, higher-quality metal lasting over twice as long as asphalt shingles. A lower-quality metal roof can last up to 25 to 40 years, with higher-end metal roofs lasting well up to 70 years. The same goes for several kinds of gutters made of metal.

Clay Tile Shingles

Popular in the Midwest, clay tile or concrete tile shingles are excellent choices for their longevity, durability, and resistance to the elements. These shingles are more expensive than asphalt and can be more expensive than metal (depending on the metal’s thickness and the size of the house). They also have more construction requirements and limitations, requiring additional support for roofs to maintain their increased weight. However, after everything is said and done, clay tiles can last up to 100 years, with cement tiles lasting over 50 years. 

Slate Shingles

Slate is the cream of the crop for roof tiles, being the most expensive, heaviest, and longest-lasting. Slate roof tiles come in two rough categories, soft and hard. Soft slate roof tiles can last from 50 to 125 years, while hard slate can last up to 200 years. Slate, like clay, is extraordinarily heavy, requiring more time to build and install by specialist contractors or structural engineers.

Signs of an Aging Roof

Each roof material has different signs of wear and tear. However, since asphalt shingles have the shortest life span and have the lowest resistance to weather and the elements, they show their age the easiest. You will also have to worry more about replacing your asphalt shingles than any other roofing material because a single home will go through several sets of asphalt shingles in its lifetime. In contrast, most other materials will last the home’s entire life span and need to be replaced at most once. Let’s go over some signs that your asphalt shingles need to be replaced.

Curled, Blistered, or Buckled Shingles

The first notable indication of an aging asphalt roof is damaged shingles, which manifest as curling, buckling, or blistering. As shingles age, they begin to degrade and warp. Over time your shingles will begin to peel and curl at the edges, with the center still attached to the roof. This unique look is referred to as “curling.” “Buckling” is similar but inverted, as the center pops upward. Both of these symptoms can also be the result of poor attic ventilation or improper installation, namely, not getting enough asphalt on top of the shingles. Blistering, on the other hand, looks like holes or pockmarks in your shingles. These blisters occur when moisture or volatiles burst out of the shingle. Blistering is typically caused by overheating from a poorly ventilated roof but can also appear as shingles age and degrade. 

Missing Shingles

Missing shingles can be caused by a few things, the most common of which is natural aging. As your shingles age, the asphalt begins to wear away, and the nails and sealing strip used to hold them together and onto the roof begins to degrade. This degradation will begin as curling, but if not taken care of (either by resealing or a complete replacement) will then result in missing shingles. As the shingles’ connection to the roof weakens, strong winds and rains will make quick work of them, sending them flying. 

Keep in mind that a few missing shingles here and there might not indicate aging — instead, some other problems like moisture, poor ventilation, or improper installation could be to blame. If you spot a missing shingle, replace it quickly, as it leaves the underlayment exposed and weakens the surrounding shingles’ connection.

Missing Granules 

Asphalt shingles are made of an organic or fiberglass core, which is then coated with asphalt and mineral granules. The granules have several purposes but primarily exist to protect the asphalt from rain, snow, sleet, and UV rays. The asphalt will quickly crack, weaken, and fall off without the granules. As your shingles age, the outer layer of granules will eventually wear down from weathering. You can see this by large, dark patches along roofs where the color from the granules has lessened. 

Damaged or Clogged Valleys 

A roof valley is where two roof slopes meet, funneling water and debris into your gutters, and are invaluable for proper drainage. As your roof ages, these valleys become less effective as shingles curl and go missing. Eventually, valleys will become less effective at funneling water, which can lead to pooling or leaking in the attic. In extreme cases, a deteriorated roof valley may even collect debris like leaves, tree limbs, or, comically, other fallen shingles. 

If you spot a large amount of debris in your roof valleys, you should try to remove it promptly, and while doing so, check over the shingles in the valley. If they are blistered, warped, or curling, it may be a sign that your roof is aging. 

Roof Moss

It should come as no surprise that moss growing on a roof is a strong indicator of its age. Aging roofs lose the ability to resist moisture as the asphalt wears away, and this moisture can lead to the growth of mold, rot, fungus, and even moss or algae. This problem further shortens the life span of your roof by growing under and between the shingles, loosening their connection, and weakening the roof. If you spot algae and moss growing on your roof, it is a good sign that you should consider replacing it. In the meantime, you will need to remove the moss and algae ASAP. Here are are some steps for removing this green, fuzzy roof destroyer: 

1. Wear appropriate attire, including eye protection, gloves, and appropriate footwear.
2. Carefully ascend the roof with an extendable ladder.
3. Spray down the area with a garden hose.
4. Using a soft bristle scrub brush, gently brush downward in the direction of the shingles. 
5. Apply a solution of about 2 cups of white wine vinegar to 2 gallons of water to the algae-affected area. 
6. Let the solution sit for half an hour. 
7. Spray down with a garden hose.

What About Other Roofing Materials? 

While asphalt shingles are the quickest and most direct in showing their age, the other roofing materials we mentioned also have telltale signs of growing old. Here is a quick rundown of all the best indicators of each roof material’s age: 

• Wooden shingles: As wooden shingles age, their water and weather resistance begins to lessen, leading to signs like curling. Similar to asphalt shingles, the ends of wooden shingles begin to curl up as they age. Some homeowners like this appearance, but as time goes on, the shingles will further deteriorate and begin to crack and split, allowing moisture into the core of the wood. The final sign of an aging wooden roof is the growth of moss, algae, and mold inside the wood’s splits, cracks, and gaps. 
• Metal roofs: A few signs can point to an aging metal roof. The first is chipping or missing paint. When metal roofs are installed, a weather-resistant paint or coating is applied. As the roof ages, this coating wears down. Eventually, this will lead to rusting, leaking, and even structural weaknesses like holes. 
• Clay tiles: Clay roof tiles last longer than asphalt shingles but will still eventually wear out. You will know it’s time to replace tiles when you see cracks and chips, water damage from a weakened underlayment, and stains on your eaves. 
• Slate tiles: Slate tiles usually last as long as the house they sit upon, but some exceptionally long-lived structures will eventually need a slate tile replacement. You will know it’s time to replace a slate roof when the color of the slate begins to fade, take on a mottled appearance, or begin to “rot.” Slate rotting is when other materials inside the slate, normally calcite and iron sulfides, begin to expand and contract slowly, forcing the micro-thin layers of slate apart. Over time, this process, called delamination, makes the slate separate, with large chunks falling off or holes appearing. This appearance makes the slate look “rotten” as a result. Delamination will eventually lead to entire tiles or sections of tiles falling off, giving a clear warning sign that your roof needs replacing. 

Final Thoughts

No matter what material your roof is made of, there will always be telltale signs of weathering and aging. Asphalt, while less expensive and easy to install, shows its age more quickly and has the shortest shelf life of any roofing material. However, if you keep an eye out for the signs of aging mentioned in this article, you will be able to get your roof replaced before water can sink in, causing even more damage.