Are you seeing little puddles forming all over your parking lot? You could have a problem with water drainage, asphalt compaction, or a problem with your sub-base.
We talked with Tim Hansen, Project Manager at Wolf Paving, to weigh in on parking lot puddles and if it's something property owners should be worried about.
Question: What causes these puddles in parking lots? Could it be from cars parked in the same spot every day?
Answer: To a certain extent, yes, the depressions may be a result of stationary weight over a long period of time. One of the great benefits of asphalt pavement for parking lots is that it is flexible and allows for the natural movements caused by the forces of nature without cracking, heaving, or deteriorating. Because asphalt is a flexible pavement, stationary weight repeatedly in the same spot can slowly deform the pavement over time; this is called rutting. Pavement rutting is characterized by indentations along the wheel paths of cars.
The puddles may also be as a result of grade depressions. Grade depressions are characterized by sections of the pavement settling lower than the surrounding pavement. These can be identified easily after a rain shower because of water pools in the depressions.
Question: What causes rutting and grade depressions in asphalt?
Answer: Rutting can be caused by any number of factors.
For example, cars that are stopping to park in a stall usually have been driving for a period of time and the temperatures of the tires themselves can raise the temperature of the pavement ever so slightly. Which may soften it to a very slight degree, but this is typically not the root cause of rutting.
Quite often, rutting and grade depressions are caused from poor compaction during the installation process. Compaction is a key to a durable, strong pavement. If a parking lot, for example, is compacted with a roller that is too small, the surface will not get the compaction the pavement really requires. Aesthetically, you cannot tell the difference, but down the line, a parking lot with inadequate compaction will see rutting and grade depressions significantly sooner.
Question: What would Wolf Paving do to fix this parking lot so water does not pool this way, or is this typical?
Answer: It really does depend on the condition and the pitch of the lot. In the supplied picture, the pavement appears to be in very sound shape- other than the rutting caused by car tires. In this case, there are two repair methods I’d recommend:
- The more expensive method would be to mill an 8-9 foot strip all along the walkway, apply a tack coat adhesive, and pave a new surface layer where you have milled. The lot is stable and in good shape, and this method would have the most longevity.
- The second option would be to perform a series of infrared heats all along the walkway where there are puddles. After this step, we would follow with an application of sealcoat to the parking stalls to have the infrared patch areas blend in as much as possible with the surrounding pavement from an aesthetic standpoint. In addition, this will seal the infrared areas from environmental oxidation.
Question: Would porous pavement be a solution for my parking lot?
Answer: Porous pavement could be a solution here if the lot was designed for porous pavement from the beginning or the lot is of a configuration where installing drain tile is possible.
Porous pavement drains water through it into the base material. The base material for a porous section of pavement has many voids in it to help the water travel away from the pavement and drain towards either a drain tile system, a natural detention/retention system, or if the lot was designed for it, remain in a very thick cross section of stone that slowly percolates the drainage water into the soils below. Simply removing a section of conventional asphalt pavement and replacing it with a porous pavement is not an option as considerations for where the drainage water goes once it drains through the pavement have to be made.
Thank you, Tim, for your expertise! Do you have a question for Tim on asphalt repair? Let us know in the comments or send us a message.
With over 75 years of asphalt paving experience, from highways to driveways, we are your local source for all of your asphalt paving needs.
For more information on Wolf Paving or to request a free quote for your next paving project contact one of our two offices. If you live or work in the Milwaukee area, call us at 262-965-2121. For the Madison area, call us at 608-249-7931.
