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and neighborhood landscapers strive to Plastic Reinforced Grid and save money. Instead of a solid run
achieve. If you use store-bought pavers, this of asphalt or concrete, it consists of two
system will cost a little more than pervi- narrow, parallel strips of concrete, spaced
A third option to explore is Porous ous concrete or plastic reinforcing grid so that a vehicle’s wheels can drive on
Paver Systems. Paver systems are imper- for the surface, but will save you money them. The strip of grass in the middle
meable blocks made of brick, stone or using less materials and time preparing allows water to soak in and the construc-
concrete, but unlike typical paver instal- the base. Typical installation cost would tion costs will be cheaper because less
lation the joints are not grouted in. The range from $5 to $10 per square foot. The concrete is required. Standard base mate-
pavers typically come one of two ways. greatest advantage to this system is that a rial, compaction and concrete are used
Interlocking blocks have spaces or holes variety of shapes, colors and patterns can for this technique. According to the City
within the individual pavers themselves be incorporated into the surface to tailor of Pasadena, Calif., Zoning Code Book,
and fit together in a pattern. Standard pav- the look from highly formal to a casual the dimensions for a Hollywood Drive-
ers are just individual blocks that are laid garden. Let your imagination run wild. way give two paved wheel tracks each
in a pattern with larger spaces between Probably the second largest impervi- between 2.5- and 3.5-feet wide, separated
them. ous surface in your yard, next to your by a planted strip at least 3-feet wide.
rooftop, is your driveway. Impervious
As with all of our porous pavement surfaces cause rainwater to immediately One thing to bear in mind with this
options the base must be able to infiltrate runoff instead of being absorbed into the
the water coming through. A typical in- ground which can cause flooding and Hollywood Driveway
stallation would use a base of 4-inch deep mean increased pollution and reduced design, however, is that if you have to
course washed stone (3/4 inch diameter groundwater supplies for your communi- negotiate a curve or have an extremely
or TDOT Grade E) with a 1-inch deep ty. A 10-foot wide by 40-foot long drive- long driveway, it may be hard to fol-
layer of masonry sand on top. If the area way will shed about 250 gallons of water low the path and keep your wheels on
is large or is expected to collect run-on during a 1-inch rainstorm. Multiply the driveway, so driver skills must be
from other areas an under drain of 4-inch that by thousands of homes, and you’re taken into account. Another benefit to a
plastic perforated pipe can be used below talking about a tidal wave of potentially Hollywood drive is that it will lower the
the sub-grade. If the grid is to be filled tainted water running into your local temperature around your house in the
with soil or sand for grass, a layer of filter storm sewer system and streams. summertime since the vegetation will
fabric should be placed over the base to If you are considering building or absorb heat instead of reflecting it like a
stop the base from clogging. The joints on replacing your driveway, why not add standard concrete slab.
individual solid pavers should be at two a little bit of old fashioned glamour to
to three times wider than typical grouted your yard? A “Hollywood Driveway” is The last alternative to standard drive-
joints. Interlocking blocks are designed a great way to add distinction, greenery way construction is to use small stones
to be placed touching each other. Infil- or pea gravel to make your driveway.
trate rates for this kind Porous Pavers This is the least expensive of all the
of system are less than pavement options and allows water to
pervious concrete or penetrate into the ground. By stones, I
the plastic reinforcing mean tumbled, rounded aggregate, as
grid pavements, but will opposed to crushed gravel, which will al-
handle flows of one to low less water to soak in. This technique
three inches per hour. is easy, but will require more frequent
Maintenance is minimal maintenance unless a tall border is
and requires periodic installed too.
sweeping or blowing of
leaves and grass clipping Not only will these construction tech-
off the surface and refill- niques improve your yard, but together
ing of the voids every few they can all help the health of the stream
years. and wildlife in your neighborhoods.
View online at tnpublicworks.com 25
