How Long Does a Tar and Gravel Roof Last?

A sturdy roof is the unsung hero of every property, protecting us from the elements day in and day out. For homeowners and property managers, understanding the lifespan of a roofing system is crucial for long-term planning and maintenance. In this comprehensive guide, we unravel the mysteries of tar and gravel roofs, walking you through their lifespan, common issues, and tips for extending their years of service.

Types of Gravel and Tarred Roofs

Modified Bitumen Built-Up Roofing

Modified bitumen, often called “torch-down” roofing, is a modern take on traditional tar and gravel roofs. This system involves applying multiple layers of waterproof roofing material that uses a combination of asphalt and synthetic rubber or plastic, which offers enhanced durability and resistance to cracks, leaks, and weathering.

Ballast Tar & Gravel Roofing

Ballast roofs, also known as “tar and gravel” roofs, have been a staple in the roofing industry for decades. These roofs consist of a base layer of tar with layers of roofing felt and a top layer of river-stone gravel, which acts as a protective barrier against the sun’s UV rays, weather, and physical damage.

Factors Affecting Roof Lifespan

Understanding the lifespan of a tar and gravel roof is not as straightforward as naming a specific number of years. Several factors can significantly influence how long your roof will last.

Climate and Weather Conditions

The geography and typical weather patterns of your locality play a significant role in roof longevity. Properties in areas prone to extreme heat, cold, or heavy rainfall may experience more rapid roof deterioration.

Installation Quality

The skill and experience of the roofing contractor can’t be overstated. A poorly installed system is likely to develop issues prematurely, reducing the overall lifespan of the roof.

Roofing Materials Used

The quality of the materials directly impacts the durability of the roof. Using low-grade tar or insufficient gravel coverage, for instance, can lead to problems like brittle shingles and faster wear and tear.

Factors Affecting Roof Lifespan Gravel

Maintenance and Regular Inspections

Proactive maintenance and periodic inspections can identify and rectify small issues before they escalate into major problems. Neglecting routine care can significantly reduce your roof’s lifespan.

Average Lifespan of Tar and Gravel Roofs

While a tar and gravel roof can theoretically last for several decades, the actual lifespan varies based on the factors we discussed.

Range of Lifespan Based on Various Factors

Typically, you can expect a tar and gravel roof to last anywhere between 20 to 25 years with good maintenance and favorable conditions. However, in areas with extreme weather, the lifespan might be shorter.

Typical Lifespan Expectations

With proper care and under normal conditions, a tar and gravel roof can give you 25 to 30 years of service. However, understanding that it will not last indefinitely is crucial for long-term property planning.

Signs of Wear and Damage

Recognizing the signs of an aging roof is the first step in maintaining its health for as long as possible. Here’s what to look for:

Visible Signs of Deterioration

Look out for areas where the gravel is thinning or missing, where ridges or bubbles may be forming, or where the tar seems to be wearing away.

Common Issues That Arise with Tar and Gravel Roofs

Leaks, sagging, cracked or blistered roofing, and membrane shrinkage are all common problems that could indicate that it’s time for a professional inspection and maintenance.

Extending The Lifespan Of A Membrane Roof

Extending the Lifespan of Tar and Gravel Roofs

There are several proactive measures you can take to prolong the life of your tar and gravel roof.

Regular Maintenance and Inspections

Scheduling routine inspections, at least once a year, and prompt repairs can significantly add to the life of your roof. Inspection after major weather events is also wise.

Addressing Issues Promptly

If you notice any wear, damage, or leaking, don’t wait for it to worsen. Immediate repairs can prevent larger, costlier problems later on.

Roofing Maintenance Tips for Homeowners

Clearing your roof of debris, maintaining proper drainage, and addressing algae or mold growth can help maintain your roof in good condition for longer.

When to Replace a Tar and Gravel Roof

Eventually, the time will come when repairing your roof is no longer a cost-effective solution, and it’s time for a replacement.

Indications That a Roof Replacement is Necessary

If your roof is approaching the end of its expected lifespan, or if it’s been more than 25 years since installation, you should start seriously considering a replacement. Additionally, if you’re frequently experiencing leaks or extensive damage, it’s likely that a replacement is necessary.

Factors to Consider When Deciding on Replacement

Cost, the extent of the damage, the potential for further issues, and the types of roofing materials available should all be factors in your decision to replace your roof.

What Are The Benefits Of Having A Tar And Gravel Roof?

A roof made of tar and gravel has several advantages. It is a sturdy, long-lasting option that can be cost-effective over its lifetime. The ballast layer of gravel offers excellent fire resistance and can also provide additional insulation. Its robustness makes it resistant to foot traffic, hail, and other external aggressions compared to other roofing types, making it a popular choice for commercial and industrial properties, where durability is a must.

When You Should Not Choose A Tar & Gravel Roof?

While tar and gravel roofs offer numerous benefits, there are situations where another roof type may be more suitable. For example, if your building structure is not designed to handle the weight of a ballast roof, or if your property is located in an area with fire code restrictions that limit the usage of gravel roofs due to the potential for windborne embers during wildfires, you may need to consider an alternative.

Different Types Of Membrane Roofs And Their Lifespans


A tar and gravel roof should be replaced when it reaches the end of its expected lifespan or when the cost of continual repairs begins to outweigh the benefits. If you’re noticing leaks, widespread damage, or significant areas that are worn out, it’s a strong sign that it’s time to replace.

Common issues with tar and gravel roofs include poor drainage leading to ponding water, leakage due to membrane shrinkage or cracks, damage from foot traffic or excessive weight, and the need for regular upkeep to maintain the layers of gravel and tar.

Regular inspections are key to catching maintenance issues early. Look for signs such as loose or missing gravel, bubbles in the membrane, and any leaks that appear. Plan for professional maintenance at least once a year and after any severe weather conditions.

Regularly scheduled maintenance, prompt repairs, keeping the roof clear of debris, and managing algae growth can all help extend the life of your tar and gravel roof. Ensuring proper ventilation and insulation beneath the roof can prevent damage due to temperature fluctuations. Additionally, conducting regular inspections can help identify and address potential issues before they become major problems.

By staying on top of maintenance and keeping an eye out for potential problems, you can ensure that your tar and gravel roof provides years of reliable service. Remember, a well-maintained roof not only protects your property but also adds value. Whether you’re a homeowner or managing multiple properties, making knowledgeable choices about your roofing can save you money and headaches in the long run.