Page 302 - Masonry and Concrete

Paving

301
PAVING

brick, but they are solid and do not have holes cored through the mid-
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dle. When laid with standard 8-in. mortar joints, this creates a 4-in.
8-in. module. Paving bricks that are designed to be laid butted
together without mortar are a full 4-in. 8-in. face size so that patterns
will still lay out to a 4-in. module. This makes it easy to plan the
dimensions of the paving based on whole and half-size units to mini-
mize the amount of cutting. It is important to use the correct size unit
for the type of paving planned. All bond patterns can be achieved with
actual 4 8-in. units laid dry and tight, or with nominal 4 8 in.
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units laid with 8-in. mortar or sand joints. Patterns that require the
width of the unit to be exactly one-half the length may not be laid dry
and tight using nominal dimension units designed for mortar joints,
and vice versa.
Many different effects can be achieved with standard rectangular
brick pavers by varying the bond pattern in which the units are laid
(Figure 8-25). For driveways with units laid in a sand bed, choose a
pattern that does not have continuous joints in the same direction as
the path of travel. These will be unstable because the units will have a
tendency over time to slide forward or backward because of the
repeated braking and acceleration of cars. If you use a pattern such as
the running bond, be sure the continuous joints are laid perpendicular
to the path of the vehicles. A pattern with the units laid in a more intri-
cate design like the herringbone or basketweave will usually prove to
be most stable against sliding, displacement, and the formation of ruts.
Concrete slab bases for rigid brick paving should be 4 in. thick and
reinforced with welded wire fabric as for a driveway, sidewalk, or patio
slab as described above. Existing concrete slabs can also be used to sup-
port rigid brick paving as long as there are no major structural cracks.
Minor cracks will not be harmful, but they should be patched. If you
pour a new concrete slab to serve as a rigid paving base, make sure that
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it slopes 4 in. per foot to drain water. Depending on the size and shape
of your project, and the contour of the ground around it, the surface can
slope to one side or be crowned in the middle to shed water off both
sides. Be sure to excavate deep enough to allow for the thickness of the
concrete slab plus the thickness of the mortar setting bed and the
pavers. Relocate any existing downspouts that would drain onto the
paving, or use flexible drain pipe to route the water runoff around the
paving. Finish the concrete surface with a wood float finish so that it

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