What Causes Alligator Cracking in Asphalt
- parkdalesales1
- Jun 10
- 5 min read
Updated: Sep 4
If you've noticed a network of cracks forming in your asphalt driveway or parking lot that resembles reptile skin, you're likely dealing with alligator cracking. Also known as fatigue cracking, this type of asphalt deterioration is a warning sign of more serious structural problems. In this blog, we’ll explore what causes alligator cracking in asphalt, the warning signs to watch for, and the best options for prevention and repair. Whether you're a homeowner, commercial property manager, or municipal planner, understanding these signs can help you make informed decisions about pavement repair and maintenance. Addressing these issues early helps avoid safety hazards and costly full-depth repairs down the road.
Understanding Alligator Cracking and Why It Happens
Alligator cracking refers to a pattern of interconnecting cracks on asphalt surfaces, typically caused by underlying structural failures. The cracks often form a scaly, mosaic-like pattern—hence the name. This type of cracking usually indicates that the pavement’s base or subgrade can no longer support the weight above it, leading to the asphalt surface flexing and eventually fracturing.
Subbase failure, moisture infiltration, poor construction techniques, and prolonged stress are common culprits. When the base layer weakens, the asphalt becomes brittle and begins to break apart under repeated vehicle loads. These cracks tend to start small, but as the problem worsens, they expand into larger areas of surface damage, ultimately making the pavement unsafe and unsightly. Without prompt intervention, these weakened sections often lead to potholes, edge cracking, and complete surface failure.
Common Causes of Asphalt Cracking and Surface Damage
Several factors contribute to asphalt cracking and general surface damage. Understanding the root causes helps in both prevention and targeted repairs. These issues often occur in combination, accelerating deterioration if left unaddressed.
Heavy Traffic and Structural Stress
Consistent exposure to heavy vehicles — such as delivery trucks, school buses, or construction equipment — puts intense pressure on asphalt surfaces. Even residential driveways can experience stress from parked trailers, RVs, or large service vehicles. Over time, this stress fatigues the pave ment, especially if the asphalt mix or subbase wasn't designed for such weight. The result is a gradual breakdown that first appears as fine cracks but soon leads to significant structural damage.
Poor Drainage and Water Penetration
Water is one of the most damaging elements to asphalt. When water doesn't properly drain away from paved surfaces, it seeps through cracks and joints, saturating the subbase. During Ontario’s cold months, this trapped moisture freezes and expands, creating internal pressure that weakens the structure from below. Even in warmer months, standing water promotes erosion, plant growth, and softening of the pavement's foundation, which contributes to more frequent and severe cracking.
Low-Quality Materials and Improper Installation
Sometimes, alligator cracking can be traced back to the original construction. If the asphalt mix lacks sufficient binder or the base layer wasn’t adequately compacted, the pavement is far more vulnerable to early failure. A thin asphalt layer, or improper grading that leads to ponding water, further exacerbates the problem. Using high-quality materials and experienced asphalt contractors is essential to preventing early deterioration.
Warning Signs Before Full Asphalt Failure
Before alligator cracking becomes severe, other signs often appear first. Catching these early warning indicators can help property owners take action before major repairs are needed:
Fine, linear driveway cracks that appear without significant cause
Surface ravelling, where small pieces of aggregate become loose, leaving the surface rough
Depressions or low spots that consistently collect water after rain
Faded colour and a brittle, oxidized texture that signals aging asphalt
Edge cracking or small patches of localized surface deterioration
Recognizing these symptoms early allows for timely intervention, such as sealcoating or targeted crack sealing, helping to prolong the life of the surface and reduce the need for major repairs.
How to Prevent Alligator Cracking in Asphalt Surfaces
Prevention is key to extending the life of your asphalt. Regular maintenance not only reduces the risk of structural failure but also saves you money in the long term. A proactive approach includes:
Conducting routine inspections after seasonal changes or heavy storms
Removing debris, oil spills, and other contaminants that degrade the surface
Applying a sealcoat every 2–3 years to protect against UV rays and moisture
Promptly sealing small cracks to prevent water intrusion
Improving site drainage with proper grading and edge protection
These steps help maintain the flexibility and integrity of asphalt surfaces, particularly in regions like Ontario, where climate conditions are tough on pavement.
Sealcoating and Crack Sealing Techniques
Crack sealing is one of the most effective methods for preventing moisture infiltration. It involves cleaning and filling cracks with a flexible, rubberized sealant that bonds with the asphalt and expands/contracts with temperature changes. Sealcoating, on the other hand, acts as a protective layer over the entire surface, shielding it from oxidation, UV damage, and chemical spills.
These methods are ideal for early-stage maintenance. However, once cracking becomes widespread or the pavement starts to sink, deeper structural repair may be needed. Routine crack sealing and sealcoating can easily double the lifespan of a well-installed asphalt surface.
Repair Options for Alligator Cracking and Surface Failure
Once alligator cracking appears, it’s crucial to take action based on the extent of the damage. Here are common asphalt repair options:
Asphalt patching: Best for small, localized damage. This involves cutting out the affected area, preparing the subbase, and applying new hot-mix asphalt. It's a fast and affordable fix but not ideal for extensive damage.
Asphalt resurfacing: A cost-effective solution when the damage is surface level but widespread. Resurfacing involves applying a new asphalt layer over the existing base. It significantly improves curb appeal and extends the pavement’s service life.
Full-depth reclamation or replacement: Necessary when the base layer is compromised. This process removes the entire existing surface and base materials, then rebuilds from the ground up. It’s the most extensive repair but ensures a long-lasting result.
When to Consider Asphalt Resurfacing
If the cracks haven’t penetrated the base layer, resurfacing can be an excellent solution. It restores appearance, strengthens the surface, and extends lifespan without the cost of full reconstruction. This is ideal for parking lots, private roads, and residential driveways where the subbase remains structurally sound.
Is It Time to Call in the Experts?
Widespread cracking or signs of structural weakness shouldn’t be left to DIY fixes. While cold-patch products or temporary sealants might cover the problem briefly, they won’t address the root cause. Professional contractors can assess the depth and cause of damage, recommend the right solution, and ensure lasting results with proper equipment and materials.
If you’re seeing growing cracks, water pooling, or surface crumbling, it’s time to schedule a professional assessment. Our experienced team at Parkdale Paving can guide you through the options and recommend the best path forward based on your specific pavement conditions and budget.
Talk to Our Team About Your Asphalt Concerns
Seeing signs of alligator cracking in your driveway or parking area? Don’t wait for the damage to get worse. At Parkdale Paving, we offer expert pavement assessments and long-lasting asphalt repair solutions tailored to your surface needs. We’ll help you determine whether simple maintenance, resurfacing, or a more in-depth repair is right for your property.
Contact us today for a free consultation and keep your pavement performing at its best.
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