BUILDING FOUNTAINS AND PONDS - Fountain
and Garden Pools 10
The stone coping may be placed at any
time after the concrete
has been poured for the sides, but usually
it is not built until the
pool is lined in order to avoid the spilling
of mortar or asphalt on the
stones. The stones are placed in a bed
of fresh mortar. The opera-
tion is essentially the same as the setting
of flagstones in mortar in
the construction of a stone terrace.
The top surface of the pool
sides is swept clean and moistened but
not made so wet that water
stands on it. A 1:3 mortar is used and
joints are made
1/2 in. or 34 in. thick. The stone also
is moistened and is well bedded
in the mortar with a sliding or circular
motion. Joints between the
stones are filled with the same mortar.
Some stonecutting is usually necessary.
Linings are made by casting the footings
and sides in a form. They are more expensive
to construct than the kind of lining
described in the preceding para-
graph; but a somewhat stronger lining
which should be more resist-
ant to frost-cracking is produced. The
footings and side wall are
first cast by standard methods in double-walled
forms.
The concrete reinforcing mesh is placed
in the form before the con-
crete is poured. If the bottom can be
constructed and the pool filled on the
same
day that the forms are removed, they
can be taken off in 48 hours.
All of the natural soil between the footings
is removed and replaced
with well-tamped cinders or gravel. The
next operation is the plac-
ing of a strip of plywood 4 in. wide
all around the excavation on the
footing. These strips should be tapered
slightly so as to make their
removal easy (the tapering can be best
done with a sanding ma-
chine), and they should be oiled with
automobile lubricating oil to
prevent adhesion of the concrete. Next
the steel reinforcing mesh
is suspended in the excavation so that
it is about 2 in. off the bot-
tom. It can be supported on a minimum
number of small stones,
but a better method is to hang it from
wires which are supported on
planks placed across the excavation.
The concrete mix is then shoveled into
the excavation and packed as well as
possible around the reinforcing mesh.
Enough should be placed so as to make
a layer about 4 in. thick. After the
mesh has been completely covered, the
wires can be cut free of the
planks and the planks moved aside. At
the lower end the wires are
cut off close to the concrete, and the
short ends are cut off and bent
close to the concrete. The concrete is
then finished by smoothing
it with either a steel trowel or a wood
float, and the bot-
tom is shaped at the same time so as
to pitch toward the drain.
Within an hour or two after the bottom is finished,
the pool
should be filled with water, and the water supply shut
off again.
The back fill around the sides should be placed. These
two opera-
tions will prevent the concrete drying out before it
has cured. The
stone coping may be placed on the same day or later.
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