Page 313 - Masonry and Concrete

Paving

312 CHAPTER EIGHT

pavers are always laid on a sand setting bed, but the installation
method is a little different than for mortarless brick paving. If the soil
is naturally well drained and stable, the sand bed for sidewalks and
patios can be placed directly on the excavated subgrade. If the nat-
ural drainage is poor or the soil is soft, you will need to add a 4-in.
gravel drainage base below the sand for driveways, or a 2-in. gravel
base for patios or sidewalks.
Like mortarless brick paving, concrete masonry pavers require
some method of containment at the edges to keep the units from slid-
ing. Some alternative solutions include landscape timbers, concrete
curbs, or a metal edging system as shown above for brick paving. Some
paver manufacturers make a special curb unit which is used to form
the edges of the paved area. To install the paver edging, stretch a string
line between wooden stakes to act as a guide for the height and align-
ment of the edging. Paver curbs are usually set even with or slightly
higher than the finished surface of the paving. Make a trench alongside
the excavated area that is the same width and full depth of the curb
unit. Put a little sand in the bottom of the trench, and set the pavers on
end with the flat side against the string line. Tamp the pavers down
with a trowel handle or rubber mallet to get the right height. Butt the
edge pavers snugly against one another.
Place a weed-block membrane as described above for mortarless
brick paving. Fill the excavated area inside the edging with a loose
layer of well-graded fine and coarse sand. Allow about one cubic yard
of sand for every 150 sq. ft. of paving area. Keep the sand stockpile
and any exposed sand in the paving bed dry during wet weather by
covering it with plastic sheeting. Screed the sand to a uniform thick-
3
ness of about 1- 4 in. using a straight length of 2 4 with a length of
1 4 nailed to it. Do not stand or kneel on the sand bed before setting
the pavers. Beginning in one corner, place the pavers on the sand bed
1
leaving only about 8 in. between units. Use a string line to maintain
the coursing in straight lines. At the end of each work day, tamp or
vibrate the units to compact the sand bed and settle the pavers into
place making a single pass over the pavers with a vibrating plate com-
pactor (Figure 8-37). Spread dry sand over the pavers and fill the
joints by sweeping the sand around. Make a second pass with the
vibrating plate to complete compaction, and sweep excess sand from
the surface.

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