There are Three essential elements to constructing a long-lasting commercial parking lot:
- Subgrade preparation
- Drainage
- Pavement thickness
If any of these steps are flawed, the driveway or parking lot will probably not meet long lasting expectations.
Subgrade Preparation
Firstly we @BradleyAsphalt, will come in and survey the damage to the existing asphalt surface. Our preparation work involves cutting out humps or indentations or potholes, levelling them and removing bad soil. If there are structural problems, we will remove the old asphalt, dig out the soft, damaged part of the subgrade and refill it back up with 2 inch rock, including densely graded aggregate to top it off. Densely graded aggregate usually consists of .75 inch aggregate with high dust content. On surfaces that have 20 years plus, we would use a stringline to ensure correct levelling. Part of the preparation also includes removing trees or roots, grass along the side of the parking lots and cleaning the surface of old asphalt. Then we are able to mill along the subgrade.
10 Aug, 2021
All parking lots age and deteriorate and eventually become a safety hazard. If your parking lot is showing signs of deterioration and aging or looks patchy and uninviting, it may be time to overlay or completely redo the existing asphalt.
Drainage
Proper preparation of the subbase installation is the biggest issue when it comes to correct drainage of asphalt surfaces. Birdbath indentations can become icy and be a slipping hazard for pedestrians in the Northern climates. These situations can cause litigious problems for commercial property owners. Using a good drainable subbase and the correct 2 percent or more slope will ensure good drainage. Also of importance is the adequate construction of catch basins located in appropriate areas of the commercial parking lot. Once the paving has been completed it is always advisable to speak to property managers to make sure their sprinkler systems are correctly placed, avoiding over spillage of water onto the parking areas.
Pavement Thickness
On commercial jobs, we generally suggest 8 inches of dense-graded aggregate. This is made up of 6 inches of 2-inch size rock plus 2 inches of dense-graded aggregate. This will give you a strong subbase. On top of this we lay down 2 inches (compacted thickness) of binder mix and 1.5 inches of surface course.
Another important consideration once the asphalt surface has been installed is the correct signage and direction of heavy duty delivery vehicles. Many parking lots fail, not because of aging or alligator cracking but because of the failure to direct delivery, heavy duty trucks to their offloading locations. Drive throughs, exits and entrances and dumpster pad areas break down because there is not enough structural capacity and paving thickness to support heavy loads. Thousands of dollars can be saved with the correct signage and barrier control of delivery vehicles.
Asphalt pavements are extremely versatile and long lasting but careful planning, design and construction is needed in order to achieve these characteristics. Making sure that you contact a reliable, experienced company who has been in the asphalt business for many years, is advisable. The process includes following proper guidelines for subgrade preparation, drainage and thickness design.
Please call us with any of your commercial asphalt parking lot questions:
Denver Metro/Surrounding Areas
Office (303) 467-0631
Cell (303) 947-7484
Monument/Colorado Springs
Office (719) 481-9411
