Asphalt Installation: What to Expect
Asphalt, technically known as asphaltic concrete, is designed to FDOT standards. That which is used for parking lots, private normal duty roads and private driveways is known as S-III or 9.5. It has a slightly smaller rock size and therefore provides a smoother finish.
Private driveway installation, typically, consists of the following: 6” lime– rock base and 1 1/4” asphalt, finished thickness.
The soils in Florida vary considerably from county to county and even within a county. In Alachua county, especially, southwest Alachua county, there are substantial amounts of sand, limerock and sands with expansive clay mixtures. These expansive clays tend to cause cracking of foundations, driveways, or any rigid structure. The clay expands with increased moisture and shrinks when dry. This movement causes the problem. It is advisable to have a soils engineering firm test your soils before construction and make recommendations for your contractor to follow. We, at O’Steen Brothers, Inc., its officers, employees and/or representatives do not accept the responsibility to determine soil conditions, nor do we accept the responsibility for cracking of asphalt or concrete caused by ground movement of any kind. Any cost to determine the causes of ground movement and cracking shall be borne by the customer. We will make every effort to insure that installation is done according to industry standards.
Subgrade Preparation. Area to be paved will be excavated to allow for the installation of limerock and asphalt. Roots will be removed but will probably grow back and will damage your paving. Excavated materials are usually placed on site unless your proposal explicitly states that it will be hauled away and disposed. Most of the topsoil excavated, in the process, will be used to dress the edges of the driveway after asphalt is installed. The exposed subgrade will then be compacted with a steel drum vibratory compactor. Any wall pictures or other items that may fall should be secured within your home before compaction. Critical drainage areas will be checked with a survey instrument to provide the best possible positive drainage.
Base Preparation. The limerock will then be placed on the prepared subgrade bed to a finished thickness of, at least, 6” thickness. It will be balanced out and graded. If needed, water will be added to the limerock to optimize compaction. The rock is then finished to provide proper surface for paving. In some applications, the rock may be primed and sanded, usually at an additional cost to the customer. This provides the optimum adhesion of asphalt to the limerock base.
Asphalt Installation. All asphalt is made according to FDOT standards. The asphalt comes from the plant at a temperature of about 350° F. The asphalt is applied using a paving machine and thickness is checked to insure consistency. Areas that require hand looping tend not to be as smooth in final finish as machine laid areas. The asphalt is then rolled with a steel wheel paving roller and after proper cooling is rolled with a traffic roller. There may be some surficial cracks, especially in radius areas, caused by the roller. They are not structural in nature.
Asphalt is not laid using forms. Edges will not be straight or perfectly uniform. The final dress-out where topsoil is applied to the edge to cover the exposed limerock gives the driveway a finished look. Fresh asphalt has varying degrees of porosity where the asphalt coated rock is closer to the surface. This is the normal nature of asphalt paving.
It takes about six months for asphalt to completely cure. During that time it is subject to tire abrasion. Vehicles should be in motion before steering is turned. The warmer the outside temperature the softer the asphalt will be during the curing period. Use and Maintenance. You should wait, preferably, 24 hours before driving on your new driveway. We recommend that you should not seal coat your asphalt for several years. You definitely must wait, at least, 90 days. After a couple of applications of sealer, it will begin to crack. It appears that the asphalt is cracking but it is really the sealer. The terrible appearance will result in continued reapplication about every two years. Asphalt is an organic product and often acts as a fertilizer. Keep the sand blown off and treat any vegetative growth with a light application of a weed killer like Roundup.
Your asphalt driveway is warranted for one year from the date of completed installation. This warranty is limited to materials and installation. It does not cover cracks or heaving caused by ground movement or tree roots. It does not cover damages due to soil conditions such as expansive clays etc.