Your driveway is like a welcome mat for your friends and visitors. Most driveways are perpendicular to the street and on the same level but others may be curved and have a pitch to them. It's the raised type of driveways that are the most noticeable and can look like a Yellow brick Road to your home. On the flip side, faded and broken concrete can make the rest of your home look tired no matter how new the building looks.
When looking for a new driveway surface asphalt pavement is a great way to go on many levels. First, it is less costly than concrete and paving stones. Even with the high price of oil asphalt paving is a cheaper option and, as well, the job is done quicker and without forms and hours of costly labor. Paving contractors are specialized for roads and driveways and are able to create a perfect pad for your driveway quickly.
The Asphalt Process
In basic terms, asphalt paving is also termed asphalt concrete because, like concrete, it is an aggregate held together by a binding agent. In the concrete process it is Portland cement that is the adhesive and in paving it is bitumen, or asphalt cement, that glues everything together.
Hot mix asphalt pavement is a mixture of gravel, crushed rock and sand mixed with liquid asphalt, a heavy by-product of the petroleum refining process. The oil is heated, mixed with the aggregate stones and then spread out on the area in a continuous pad until the area is completely covered. A mechanized roller then pressed the mix into a hard surface.
As with any building process there has to be a firm foundation beneath an asphalt surface. Paving contractors will dig down to remove clays, porous soils, old pavement and concrete. In some cases the old surface can make a good base but most times it should be removed. Then a crushed rock base from 6 to 10 inches thick is put down depending on the use of the driveway. A good base will also prevent the surface from cracking or sinking in spots. In addition the crushed rock should be wider than the blacktop to account for drainage. It also prevents the edges of the pavement from breaking and cracking if a tire goes to far over to the edge.
The crushed rock base should be spread in layers with a heavier, bottom layer three to four inches thick. The stones in this layer should be bigger for holding power. Each layer is smoothed and then compacted with a heavy roller. The second layer is composed of smaller rocks and should be at least two inches thick.
Paving contractors will also check the grade to make sure that the drainage is away from the home or, in the event of a downward sloping driveway, allow for a drainage pipe to steer water. The lower portion of the crushed rock will provide an advantage for drainage while the top will be pressed into the asphalt surface and become part of the aggregate.
Many people like a smooth surface, and this means more small rocks and sand in the mix. However, as nice as this looks it does not stand up well to heavy traffic and large vehicles so the paving contractor will put down two layers. The bottom layer will be a heavier gravel or crushed rock. This will be rolled and shaped and then a lighter mix will be applied after a coating of asphalt cement is spread on to bind the layers. This finishing layer will be thin, about 1 to 1 and be composed of coarse sand.
Like concrete, blacktop is premixed at a pavement plant. It is delivered by truck and dumped into a spreader that actually puts the asphalt down in a wide, continuous strip. Then a mechanized roller compacts the pavement, pressing it into the base of crushed rock.
To give the surface a long life a driveway sealer should be applied yearly. This seal coating prevents the aggregate from breaking down.
Finding A Contractor
Good and Bad: Like many other contracting businesses there are good and bad paving contractors. For good contractors a homeowner should check with the local building supply places and also see who is doing paving in the area. The best advice is to find out what you need and how the asphalt process is done in your area. Then you will know what you need for your own paving project.
Ask Other Homeowners: Every summer hundreds of homeowners get new driveways. Drive around and see who has had the work done and interview them. In this way you can come up with three or four contractors whom you can interview for your own job.
Around the Block: Sometimes a paving company could be working in your area and easily shift their gear to your yard. Equipment is expensive to move so an extra job in an area cuts down on their expenses. This could save you money and get the job done quickly. However, don t be in such a rush that you do not get references. And make sure the present homeowner is happy with the job before they come over to your yard.
A good way to get qualified contractors is to contact out Contractor Directory. In addition you can post your project online and get contractors to contact you.Posted by: TrustedPros