In areas of pavement where automobiles are frequently parked, a fuel resistant
fog seal may be desirable to prevent fuel leaks from dissolving
the top layer of asphalt binder. Consult a paving contractor about the use
of any sealant.
If unsure of subgrade condition, the design for "poor subgrade" should be used
lessen the risk of premature failure.
Class G mix can
be used for thin driveway overlays.
Design driveways with a minimum slope of 2 percent (0.25 inches per foot).
Slopes less than this are difficult to construct and may not prevent pooling
of water during wet weather.
Construction Considerations
Driveways should be compacted to a minimum of 90 percent
TMD (Rice
density). Lower levels of compaction may result in driveways
that will significantly compact under a parked car load or scuff as a
result of turning an automobile's wheels while it remains parked.
Driveways should be constructed with HMA and not cold mix asphalt.
Cold mix asphalt is typically used for emergency repairs and will often
not stand up to even light automobile loads on hot days. Turning an
automobile's wheels while it remains parked can considerably scuff cold
mix asphalt.
Where there is the possibility of recurrent vegetation growth, a
quality commercial grade herbicide should be used.
WAPA Pavement Note on Driveway Paving Scams
Unfortunately, salesmen going door-to-door offering to pave driveways at very
low cost is a common home construction scam. The typical scenario (but by
no means the only scenario) begins with a salesman at a customer's door offering
to pave their driveway for a very low cost because they have some "left over
mix" from another close-by job. If the customer agrees to the work, the
scam artist will often request payment up front or in cash. They then
either do a poor job using inferior equipment and materials, do an incomplete
job and leave, or just leave without doing any work. These scams typically
result in unsatisfied consumers who end up paying for inferior work that often
must be replaced.
Selling door-to-door. Reputable HMA contractors will rarely
if ever sell their product door-to-door.
Claiming they have "left over mix". Often, a scam artist will
claim they have HMA left over from a previous job that will go bad if they do
not use it so they must offer you a great deal. Reputable contractors
carefully compute their HMA requirements and rarely have substantial left over
HMA. Additionally, once HMA cools below about 175°F it becomes too
viscous to compact. Therefore, someone driving around with "left over
mix" for several hours looking for a driveway paving job will likely have HMA
that is uncompactable. Poorly compacted HMA can result in a myriad of
problems.
Pushing you to make a quick decision. Reputable contractors
will provide a quote before doing any work so that you may shop around.
Cash only sales. Most reputable contractors take checks, and
don't require cash-only terms.
No contract offered. Most reputable contractors will offer
you a contract in advance of the work to be performed.
Deals that seem too good to be true. If the quoted price
seems very low, chances are the quality of work will also be quite low.
A quality hot mix asphalt driveway that is both functional and aesthetically
pleasing can be built at a reasonable price.
Recommended References
Asphalt Institute. Full-Depth Asphalt Pavement for Parking Lots,
Service Stations and Driveways, 5th Edition. IS-091. Asphalt
Institute. Lexington, KY. (www.asphaltinstitute.org)
