Don't Pave Over Problems: Why Drainage Testing is Crucial Before Your Asphalt Overlay Or Mill & Pave Project Begins

Before entering into a paving contract with a paving contractor, it is essential for every buyer, whether you are a commercial property owner or a commercial property manager, to be fully informed about the critical aspects of the project. Understanding the nuances of the paving process, the importance of proper drainage testing, and the potential long-term impacts on your property are crucial steps in making an informed decision. This knowledge not only helps in safeguarding your investment but also ensures that the paving project enhances the functionality and aesthetic appeal of your property while maintaining safety and quality standards.

Above: Puddles In A Parking Lot 24 Hours After A Rain Storm Has Ceased

As a commercial property manager or property owner, you are well aware that your parking lot serves a far greater purpose than merely providing a space for vehicles to park. It represents a substantial financial investment, playing a pivotal role in enhancing your property's overall appearance and appeal. Moreover, it serves as a testament to your unwavering commitment to ensuring safety and maintaining high-quality standards. This is precisely why, when it comes to asphalt paving—whether you are considering an asphalt overlay with transitional milling or embarking on a comprehensive surface milling and paving project—it is imperative to execute the process flawlessly from the very beginning. Achieving this level of precision and excellence begins with conducting thorough and proper drainage testing, and here's why this step is so crucial.

At FixAsphalt.com, we have witnessed firsthand the detrimental consequences that arise when drainage issues are neglected. Overlooking these problems is akin to constructing a magnificent house on a foundation riddled with cracks—it may appear visually appealing at first glance, but it is destined to fail over time. Water is the most formidable adversary of asphalt. When water infiltrates the asphalt surface and becomes trapped beneath it, it sets off a chain reaction of issues that can compromise the integrity and longevity of your pavement.

What Happens If Drainage Is NOT Corrected Prior To Paving:

• Premature Cracking and Potholes: Water expands and contracts with temperature changes, creating stress on the asphalt and causing cracks. Over time, these cracks grow into potholes, creating a hazardous and unsightly surface.
• Base and Subgrade Failure: Water weakens the layers beneath the asphalt (the base and subgrade). This compromises the structural integrity of the entire pavement, leading to uneven settling, rutting, and ultimately, complete pavement failure.
• Reduced Lifespan: Properly installed and maintained asphalt can last for many years. However, poor drainage dramatically shortens the lifespan of your pavement, forcing you to repave sooner than expected.
• Increased Maintenance Costs: A poorly drained parking lot will require constant patching and repairs, quickly eating into your budget.

Why Drainage Testing is Your Secret Weapon:

Drainage testing is a simple yet highly effective process that identifies areas of your parking lot where water tends to pool or drain improperly. At FixAsphalt.com, we meticulously assess your parking lot's existing drainage system. We identify those trouble spots that are prone to standing water after rain. The reason is simple: it's best to deal with drainage problems before you pave. Here is our process for how we drainage test a parking lot:

• Thorough Inspection: 

  We closely monitor the weather conditions for your specific project location, utilizing WeatherBug and MX/Weather resources to ensure accuracy. We set up detailed weather alerts for any forecasted rainfall event that is anticipated to produce at least four hours of continuous, steady rain. This proactive approach allows us to prepare thoroughly and ensure that we can effectively assess the drainage capabilities of your parking lot under realistic conditions. By doing so, we can identify potential problem areas where water may accumulate, ensuring that no detail is overlooked in our drainage testing process.

• Identify the Puddles: Our team identifies all areas where water accumulates and how they get there. We analyze the flow of water across your lot to understand the root cause of the drainage problems.  Is it due to low areas, elevated sections, flawed design, or simply poor grading from when the parking lot was initially constructed?
• Develop Solutions: Once we understand the extent and cause of the drainage issues, we can recommend the most effective solutions. These solutions will be discussed in the following paragraph.
  
  
          
  Above:  Weather Report & Puddles In A Parking Lot 24 Hours After A Rain Storm Has Ceased

FixAsphalt.com: Your Partners in Finding Solutions

The good news is that most drainage problems can be corrected. Here are some common solutions we implement at FixAsphalt.com:

• Regrading:  If the problem areas are merely low spots or puddles and the parking lot's cross slope or running slope is 2% or more, we can apply a leveling course of asphalt before paving. In some regions, this is also known as a wedge course or shimming. Essentially, the paver screed is lowered to zero with the extensions fully extended and is run over the low area. Similar to how a floor is leveled before tiling to eliminate low spots, it serves the same purpose. The asphalt will fill in the low areas without increasing the height of the level areas that are already on grade. This is very common in parking lots that may have rutting from car tires in parking stalls. 

Above Left: The parking lot was built on a former sanitary landfill.  As the garbage began to settle over 30-years the parking lot began to sink in several areas causing puddles.  To raise the asphalt to facilitate positive drainage would have required the island to be removed.  In this instance a relief drain was a more cost-effective option.

• Adding Drains: Strategically placed catch basins, trench drains and zip drains can effectively redirect water away from the pavement. On some projects, the length stormwater will have to travel to reach a catch basin would require curbs to be adjusted, swales to be installed and other expensive corrections and the parking lot will still drain slowly.  For these circumstances it's best to install a relief drain tied into a catch basin.

• Profile Milling: Using a laser, we can assess the parking lot and mark out the trouble locations.  We can mill swales, mill low areas to level them with binder asphalt prior to an overlay or correct poor drainage for an entire parking lot.  

• Subsurface Drainage Systems: Identify any areas of groundwater coming to the surface of the parking lot.  For more complex drainage issues such as this, we can install underground drainage systems to collect and remove water from the base and subgrade.

Understanding Parking Lot Drainage: Cross Slope vs. Running Slope

Most paving contractors assume that clients comprehend the disclaimer mentioned above, which is where many issues originate in a parking lot paving project.

So, with that being said... What does the disclaimer: "XYZ Paving Company is not responsible for ponding/poor drainage in areas where the grade is less than 2%" mean exactly?  

We will explain it below: 

Picture your parking lot like a gently sloped roof. You want rainwater to flow off smoothly, preventing puddles and potential damage. That's where cross slope and running slope come in.

• Cross slope is the degree of slant across the parking lot's width, like the incline of a roof from its peak to the edge. It ensures water flows from the center towards the sides, where drains or curbs can collect it.

• Running slope is the incline along the length of the parking lot, like the slope of a driveway. It guides water towards the lowest point for drainage.

What does a 2% cross slope mean?

Imagine a line 100 feet long across your parking lot. A 2% cross slope means that one edge of the parking lot is 2 feet higher than the other edge along that 100-foot line. This creates a subtle but effective slope to direct water away from the center.

Why is this important?

Proper cross slope and running slope are crucial for:

• Preventing ponding: Standing water can damage asphalt, create safety hazards, and attract mosquitoes.
• Protecting your investment: Effective drainage extends the life of your parking lot by minimizing water damage.
• Safety: Proper sloping prevents slippery surfaces and reduces the risk of accidents.

What if Corrections Aren't Possible? Transparency is Key

What Many Paving Contractors Won't Disclose... And It Could Lead to a Costly, Inferior Paving Job!

Unfortunately, many paving contractors prioritize securing a sale over providing comprehensive and honest information.   As a result, they often offer only the bare minimum of details, even if they are aware from the outset that they will not be able to effectively address the water drainage issues in your parking lot. This lack of transparency can lead to significant problems down the line, as unresolved drainage issues can severely impact the longevity and safety of your pavement. By thoroughly understanding the insights shared in this blog article, you can equip yourself with the necessary knowledge to engage in informed discussions with any prospective paving contractor. You should inquire whether they anticipate any drainage challenges in your parking lot and, more importantly, how they plan to address these issues.

The paving industry, unfortunately, does not always have the best reputation, and some contractors may not even possess the qualifications needed to accurately assess the scope of a project, let alone implement effective drainage solutions. Therefore, it is crucial to meticulously vet and qualify any potential paving contractor before entrusting them with your project. This due diligence will help ensure that you select a contractor who is not only capable but also committed to delivering a high-quality, long-lasting paving solution.

The images above illustrate the consequences of failing to address drainage before paving. The ice makes this parking lot a significant slip-and-fall hazard.

The images above illustrate the consequences of failing to address underground water before paving. Within 30 days of installation, the water will surface through the new asphalt.

What Happens If It Can't Be Fixed?

In rare instances, we may encounter drainage challenges that are simply not feasible to correct entirely. Perhaps the lot is situated in a naturally low-lying area, or the surrounding infrastructure limits drainage options.

In these situations, we believe in complete transparency. We will never try to sell you a "miracle" solution that won't work. Instead, we will:

• Clearly Explain the Limitations: We will provide a detailed explanation of the challenges and why complete drainage correction may not be possible.
• Set Realistic Expectations: We will help you understand the potential long-term impact of the drainage limitations on your pavement's lifespan and maintenance needs.
• Explore Alternative Solutions: Even if perfect drainage isn't achievable, there may be alternative solutions, such as using specialized asphalt mixes or implementing a more frequent maintenance schedule, to help mitigate the effects of water.
• Politely Decline The Project:  If we feel we cannot meet your expectations or deliver an acceptable job, we will courteously decline the opportunity to provide a proposal or contract for the work.

   

The FixAsphalt.com Difference: Expertise and Integrity

At FixAsphalt.com, we're not just asphalt paving contractors; we're your partners in ensuring the long-term success of your pavement project. We pride ourselves on our:

• Expertise: Our team has years of experience diagnosing and resolving complex drainage issues. We have seen what can happen, and we are here to help prevent future problems.
• Thoroughness: We take the time to conduct a comprehensive drainage assessment before we even talk about paving.
• Transparency: We are committed to open and honest communication throughout the entire process.
• Solutions-Oriented Approach: We don't just identify problems; we find effective and cost-efficient solutions.

Don't gamble with your investment. Contact FixAsphalt.com today for a thorough drainage assessment and let's work together to create a parking lot that's built to last.

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