Asphalt surfaces are designed to withstand heavy traffic and weather conditions, but their durability can be seriously compromised by one key factor: water. Proper drainage protects your asphalt by efficiently directing water away from the surface and underlying layers, preventing pooling, infiltration, and freeze-thaw damage that lead to cracks, potholes, and structural failure. 

Without adequate drainage, even the highest quality asphalt can deteriorate rapidly, resulting in costly repairs and a shortened pavement lifespan. Understanding how drainage safeguards your asphalt is essential for maintaining its strength and appearance over time.

What Is Proper Drainage and Why Does It Matter?

Before diving deeper into asphalt protection, it’s essential to grasp what “proper drainage” really means in the context of asphalt pavements. Drainage is more than just water flowing off the surface—it involves managing water efficiently to avoid damage both on and beneath the asphalt.

Proper drainage refers to systems and design features that direct water away from asphalt surfaces to prevent water accumulation, infiltration, and erosion. These systems can include:

Types of Drainage Systems Used in Asphalt Pavements

• Surface Drainage: This involves shaping the asphalt surface with a slight slope or crown, allowing rainwater to flow off naturally into gutters, drains, or landscaped areas. Proper surface drainage prevents water from pooling on the pavement.
• Subsurface Drainage: Below the asphalt layer, subsurface drainage systems, such as perforated pipes or gravel layers, remove water that infiltrates the base or sub-base layers, reducing moisture build-up that can undermine the pavement’s structure.

Effective water management through these drainage systems is vital because it prevents water from lingering where it can harm. Proper drainage safeguards both the visible asphalt surface and the unseen foundation beneath, which is critical to long-term pavement health.

How Water Damages Asphalt Pavements Over Time

Water is asphalt’s greatest enemy, and understanding how it causes damage helps highlight the need for proper drainage.

When water infiltrates asphalt or pools on the surface, it leads to several destructive processes:

Water Infiltration and Pooling

Water that seeps into cracks or pools on flat sections of asphalt causes the pavement material to weaken. This trapped moisture accelerates the breakdown of the asphalt binder and aggregate, making the surface more brittle and prone to damage.

Freeze-Thaw Cycle Effects on Asphalt Integrity

In colder climates, trapped water freezes and expands during winter, exerting pressure on the asphalt. When it thaws, the pavement contracts, causing cracks to widen and potholes to form. This cycle repeats annually, compounding damage and leading to premature pavement failure.

Cracks, Potholes, and Surface Degradation

Water penetration combined with traffic loads causes the asphalt surface to crack, break apart, and develop potholes. These defects not only look unsightly but also compromise safety and increase maintenance costs.

The Connection Between Drainage and Asphalt Longevity

Proper drainage extends the lifespan of asphalt pavements by protecting them from the damaging effects of water.

The benefits include:

• Prevention of Water Accumulation: By effectively removing water, drainage prevents pooling that softens the asphalt and accelerates deterioration.
• Reduced Asphalt Oxidation and Material Breakdown: Standing water increases asphalt oxidation, leading to surface hardening and cracking. Proper drainage limits water exposure, preserving flexibility.
• Prevention of Sub-base Erosion and Structural Damage: Subsurface drainage prevents water from saturating the base layers, which can cause erosion, settling, and ultimately structural failure of the pavement.

Without drainage, these damaging processes happen unchecked, leading to costly repairs or even full replacement.

Signs Your Asphalt Has Poor Drainage

Spotting early signs of poor drainage can save time and money by addressing problems before they worsen. Look out for:

• Puddles or Ponding Water: Persistent standing water after rain is a clear sign that surface drainage is inadequate.
• Cracks Near Drains or Low Spots: Cracking and deterioration often appear around poorly designed or clogged drainage areas.
• Uneven Surfaces or Sinking Areas: Uneven pavement can indicate erosion of the base due to trapped water beneath the asphalt.

Recognising these symptoms early allows you to take corrective action, protecting your asphalt investment and maintaining safety.

How Asphalt Coatings Complement Drainage Systems

While proper drainage manages water removal, asphalt coatings and sealants provide a vital protective layer that enhances water resistance.

The Role of Sealcoating in Water Resistance

Sealcoating creates a waterproof barrier that prevents water from penetrating the asphalt surface, reducing the risk of cracks and surface wear.

How Coatings Work with Drainage Systems

Drainage and coatings work hand in hand. While drainage removes water from the surface and subsurface, sealcoating ensures water doesn’t easily infiltrate in the first place, providing double protection.

Maintenance Tips to Ensure Drainage Effectiveness

• Regularly clean drains and remove debris to maintain flow.
• Inspect sealcoating every few years and reapply as needed.
• Schedule professional inspections to catch drainage or coating issues early.

Best Practices for Installing and Maintaining Asphalt Drainage

Adequate drainage begins at installation and requires ongoing care.

Recommended Drainage Installation Practices

• Design asphalt with adequate slope and crowning.
• Install subsurface drains where there is a high risk of water accumulation.
• Utilize high-quality materials to ensure the durability of your drainage systems.
  

Regular Inspection and Cleaning

Routine inspections help detect blockages, sediment build-up, or damage to drainage infrastructure. Cleaning drains and gutters regularly ensures water flows freely.

Professional Services by Asphalt Coatings Company

At Asphalt Coatings Company, we offer expert drainage assessment, installation, and maintenance services that complement our asphalt coating solutions. Our professionals ensure your asphalt remains protected from water damage through customised drainage plans.

Benefits of Proper Drainage Beyond Asphalt Protection

Beyond protecting your asphalt, proper drainage delivers additional advantages:

Proper drainage is an investment that pays off by keeping your asphalt functional, safe, and attractive over many years.

Frequently Asked Questions 

Can I improve drainage on an existing asphalt driveway without having to replace it entirely?

Yes, surface grading adjustments and installing additional drains can improve drainage without needing full asphalt replacement.

Do asphalt coatings need to be reapplied regularly?

Typically, asphalt sealcoating should be reapplied every 2-3 years to maintain effective water resistance.

What happens if water reaches the sub-base of the asphalt?

Water in the sub-base can cause erosion and weakening, leading to sinking, cracking, and eventual pavement failure.

Is professional drainage installation necessary for commercial asphalt?

Yes, commercial pavements face higher traffic and stress, so professional drainage installation ensures durability and compliance with regulations.

Ready to Protect Your Asphalt with Expert Drainage and Coating Services?

Water is the leading cause of asphalt damage, but with proper drainage and high-quality asphalt coatings, you can significantly extend your pavement’s life and avoid expensive repairs. Don’t let poor drainage jeopardise your asphalt investment.

At Asphalt Coatings Company, we specialise in comprehensive drainage solutions combined with premium asphalt coatings designed to protect your surfaces from water damage and wear. Whether you need a drainage inspection, repair, or professional installation, our team is ready to help.

Contact us today to schedule your consultation and secure your asphalt’s future with expert drainage and coating services.