What Makes Asphalt Crack? (And How to Prevent It)

Cracks in your asphalt driveway or parking lot might seem like just a cosmetic issue — but they're usually the first sign that your surface is under stress. Left alone, these cracks can lead to potholes, water damage, and even full replacement. Most causes of asphalt cracking are preventable with regular maintenance.

1. Freeze-Thaw Cycles

In Ontario, this is the number one enemy of asphalt. Water gets into small surface cracks, freezes, expands, and forces the asphalt apart. This cycle repeats all winter, turning small cracks into big problems. Fill cracks in the fall and seal your asphalt every 2-3 years to block out water.

2. Poor Drainage

If water doesn't drain properly from your driveway or lot, it pools on the surface or seeps underneath — softening the base and weakening the structure. Make sure your surface is sloped correctly, redirect downspouts away from your asphalt, and patch any low spots that collect water.

3. Heavy Loads or High Traffic

Repetitive stress from vehicles — especially larger trucks or RVs — puts pressure on the same areas again and again, leading to surface breakdown and cracking. Use proper base preparation for high-traffic areas and avoid parking in the same spot every day.

4. UV and Sun Damage

Over time, sunlight dries out the asphalt's binders, making it brittle and more prone to cracking. You'll notice this as fading from black to gray. Regular sealcoating restores the surface, keeps it flexible, and blocks damaging UV rays.

5. Weak or Improper Base

If your asphalt wasn't installed over a strong, compacted gravel base, it may not support the weight and pressure it's exposed to — especially during spring thaw or rainy seasons. If your asphalt was installed recently and is already cracking, get a professional inspection to assess the base.

6. Tree Roots and Natural Shifting

Nearby trees can push up from underneath, or soil movement can cause subtle shifts that crack the asphalt over time. Avoid planting large trees too close to the edge of your driveway and address cracks early before roots make them worse.

How to Stop Cracks Before They Start

Sealcoat every 2-3 years, fill cracks early before water gets in, maintain good drainage, sweep and clean regularly to spot issues early, fix damage in the fall before freeze-thaw cycles begin, and get a professional inspection if you're unsure.

At Lawns & Lanes, we offer crack filling and patching, sealcoating, surface leveling, and full professional inspections. Contact us today to book your driveway assessment.