Maintaining Your COncrete Parking Lot

When a concrete parking lot is a few years old, it might start to show its age. When that happens, it may be time to start maintaining that asset.

Here are a few ways you can work to maintain your concrete parking lot in order to keep it in the best shape possible. 

Cleaning 

Depending on the use of the parking lot, the climate, the types of vehicles that drive on it, and other specific facility factors, a cleaning might simply be an annual power sweeping event to remove loose debris. Power washing is a great way to remove adhered materials such as oil and grease. 

In addition to a power washing, vacuuming debris from the storm water drainage structures within the parking lot is a cleaning step you won't want to overlook. If necessary, storm water lines could also be jetted out as part of this process.

This would also be a good time to vacuum debris from the storm water drainage structures within the parking lot. If necessary, storm water lines could also be jetted out as part of this process. 

A clean parking lot is beneficial for a number of reasons:

• Markings are more visible, making the parking lot safer.
• Clean concrete reflects light better, making the lot brighter at night.
• Pavement durability is increased when buildup is removed.
• Keeping the pavement free of grease and oil will reduce the chances of pedestrian slip and fall incidents.

Restriping 

Restriping is an important part of parking lot maintenance. New pavement markings are much easier to see in low light, making it more apparent to vehicle operators where they should go while in the parking lot. Waterborne pavement marking paint is generally more economical, while sprayable thermoplastic paint markings tend to be more durable and reflective.  

Pavement sealing 

Sealers benefit the pavement by reducing moisture intrusion, improving stain resistance, reducing freeze-thaw and deicer related deterioration and helping to slow the growth of mold/mildew and the rate of efflorescence formation.  

There are two broad categories of concrete sealers: penetrating and surface sealers. 

Penetrating Sealers 

Penetrating sealers are absorbed into the concrete and are essentially invisible once applied. Typically, these materials contain silane, siloxane, silicates, siliconates or soy methyl esters (SOM’s). While these do not wear away due to traffic, they breakdown under cycles of freeze-thaw, so they must be reapplied periodically. 

Surface Sealers

Surface sealers sit on top of the concrete, becoming the wearing surface that traffic rides on. These products usually contain acrylic resins, epoxies, or urethanes. They are commonly used where colored, stamped or other decorative concrete has been placed in order to accentuate the decorative effects. Care should be taken with these to provide the necessary level of traction or grip when wet. As the wearing surface, they wear away with traffic use and eventually need to be reapplied as a result. 

Joint resealing and crack sealing 

If the contraction and longitudinal joints within the parking lot were sealed originally after construction, the joint sealants utilized have a design life of 5 to 10 years. Sealed joints should be observed regularly and designated for removal and replacement when they are no longer performing as designed. 

When this happens:

• The existing joint seal needs to be removed.
• The joint needs to be cleaned and prepared for the new seal.
• The new seal material is placed.

Cracks that develop for structural and nonstructural reasons should be sealed to keep water out and reduce cracking from the freeze-thaw cycle. 

It is generally recommended to leave tight, hairline cracks alone. These cracks are too small to effectively seal. Wider cracks may be able to be filled as is or may need to be routed open prior to filling. Crack filling materials need to fit the crack type. A rigid crack filler such as epoxy can be used with a crack that is not moving, while a semi-rigid or flexible crack filler may be needed if there is some crack movement. 

Full depth replacement 

When an area of pavement up to a full panel or two is experiencing a severe enough level of distress (such as cracking) it is time to replace that area of pavement.

• The affected concrete should be cut out and removed.
• The support soils should be reconditioned.
• New dowels and tie bars should be installed as necessary.
• The concrete should be replaced along with the necessary joints and seals.

This is likely the most intense maintenance task and is likely contingent on factors such as pavement section design, traffic type, and traffic patterns within the facility. 

Proper and timely maintenance of a concrete parking lot can help ensure many years of high-level service from that asset and a more pleasant experience for those who utilize it. To learn more about concrete and its uses in a wide variety of projects, check out our Concrete Vs. Asphalt page.