In Southern California the rainy season is generally the winter and spring months.  If you own a business, take the right steps now to prepare your asphalt or concrete parking lot before winter weather hits. Both asphalt and concrete parking lots are susceptible to water leaking into the subbase, and depending upon how former repairs were made, it is quite possible that the lot's grade and drainage design has been affected. Either way, you can end up with water ponding in the lot or running back towards the foundation of your  building.

Understanding Failure in Asphalt or Concrete Paved Lots

Standing water, heavy traffic, hot/cold cycles, and sharp or blunt force impact will all affect the condition of parking lots in a similar manner that standing water, weather, and impact will damage an asphalt-covered roof. When water is allowed to infiltrate either concrete or asphalt surfaces, it weakens the base course - and that's where the big problem begins. 

Base Course or sub-base of a parking lot is beneath the paved surface and bears the weight of all loads from vehicles, equipment, and people moving about on the finished parking lot. This material is usually crushed stone or granulated concrete and acts to evenly spread out the parking lot load to prevent deformation (or sinking) of the top surface and is critical to maintaining the life span of the paved asphalt or concrete lot.

This subbase is also affected by cycles of underground frost and thawing during colder temperatures. Even though Southern California is a warm climate, consider the sub-ground temperatures are much colder than the parking lot surface. When the soil heaves, it will swell upwards and increases the possibility of ice crystals from water droplets forming. This upward motion pushes against your parking lot surface, causing unsightly bumps and dips to form.

All parking lots must handle abuse, and concrete parking lot surfaces are no different. While concrete is a long-wearing surface material and requires little or no maintenance, they are also susceptible to impact, cracking, and crumbling which leads to water penetration, low spots, and sealant failure. Here are 5 ways to prepare your parking lot before winter weather hits.

Fill Cracks and Apply Seal Coating

Cracks in a commercial parking lot may go unnoticed by your customers, but they can lead to extensive damage including buckled surfaces and potholes. Cracks occur in all parking lots for the following reasons:

• UV rays from direct sunlight causes surfaces to become dry and brittle
• Heat combined with oil, grease, chemicals, and gasoline cause further deterioration
• Heavy traffic, especially semi-trucks cause blunt force impact
• Asphalt or concrete that has been improperly applied

Once the surface is cracked, water will penetrate to the sub base and cause a ripple effect where cracks become larger or the concrete surface starts to separate. Filling cracks and re-applying the sealcoating is more affordable than repaving the entire lot.

Repair Potholes Promptly

Here is where an extreme amount of water will penetrate to the sub base of your parking lot, and is the leading cause of pavement failures and expensive repair costs. When these large holes allow high amounts of water underneath the surface of the parking lot, the soil starts to swell or sink - causing further separation or failure between top surface and the support base.

Also, when continued vehicle loads or the impact from rolling tires is placed on a small pothole, the damage will only get larger and leave more underground voids to hold more rainwater - which starts to wash away the structural support of your parking lot. Potholes should be patched to the full depth of the lot surface, before winter arrives.

Clean Curb Gutters, Storm and Channel Drains

Storm water management is crucial to prevent back flooding during heavy rains. Again, this is a simple and affordable precaution to protect your parking lot from becoming waterlogged. Water ponding can affect the structural integrity of concrete, causing separation between surface and base, spalling, and cracking. Check where the flow of water is heading in your parking lot, and before winter sets in clear out the leaves and debris in storm drains, channel drains, and curb gutters.

Areas of your parking lot that are constantly exposed to water because of trash and leaves preventing flow will fail faster than other areas. If you have areas of standing water due to poor grading or roots clogging the municipal sewer or water lines, contact a professional parking lot paving service to discuss ways to re-pave these low lying surfaces to efficiently manage stormwater runoff. 

Install or Repair Flow Lines

If you have an area that has flooded in the past, this area may benefit from installing flow lines, which are also known as concrete swales. Concrete flowlines use gravity to direct water flow from large surfaces, and even though this repair is a little more expensive it can have a tremendous reduction on your long term maintenance cost.

You can increase the life of your lot's pavement by hiring a professional parking lot service provider to install concrete swales that are usually between 12" to 24" or more wide concrete depressions to channel water from the the length of your parking lot to an acceptable drainage area. Sometimes the existing flow lines simply need repairing due to age and crumbling concrete or changes in the municipal water drainage system.

Check Parking Lot Grade After Summer Repairs

Make sure water is flowing correctly in your parking lot to avoid flooding after you've had potholes repaired from previous seasons. Sometimes, summer asphalt repairs can cause water to travel back towards building, and possibly cause flooding into those buildings. One way to do this fairly easily is with a garden hose. Lay enough water in the parking lot to start a flow and notice any paths that are not leading to the drain system.

Your parking lot is an expensive asset and is crucial to the safety of your customers and their vehicles. Call Empire Parking Lot Services if you suspect the pitch in your parking lot has been modified due to multiple pavement repairs. Water that drains towards the foundation of a structure can cause additional problems with below ground leaking, or mold and mildew growth behind exterior walls.

We specialize in full service parking lot maintenance and repair in Southern California, including concrete repairs and ADA upgrades.