All Swim CITYPOOL, Installation And Maintenance Manual

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3. Ground works
The purpose of ground work – is to make an excavation for swimming pool body. You have to
be extremely careful at this stage (significant ground work can have negative impact on the stability
of the swimming pool, so you need to take into account the relevance of dimensions, stated in this
guide):

The excavation must be cleaned and cleared of all extraneous elements (stones, roots, etc.)
or sedimentation (friable soil etc.)

Follow excavation dimensions stated in this guide
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If the pit is too deep, the pit must never be filled with loose earth. Rubble should be used.
Place the geotextile on the bottom of the pit and restore to the desired level.

Remove smooth or friable soil around excavation works for safe filling machine moving (Bobcat
or wheel barrow), as well as giving access around the swimming pool for further works.
3.1 Water and Ground water level
If excavation work is carried out on the friable soil, it is necessary to follow specific
precautions. Sump or drainage system must be installed or the rapid removal of filtered water, rain
water or ground water. It is very important at the bottom of the hole, where the swimming pool is
set, to install one or more drainage balance wells together with peripheral drainage, consisted of
rubble for backfill. It is aimed to collect ground water and dry soil during the construction and
possible water leakage at the end of the work. In the case if the ground surface has a natural slope,
collect the water in the lowest part.
3.2 Vertical drainage or precipitator (drainage inspection wells)
The presence of this drainage is necessary condition for your swimming pool guarantee; any
equipment without planned vertical drainage is deemed not satisfying the requirements of this
installation guide.
External water level should always be below the water level of pump room bottom.
This drainage consists of a drainage pipe (laid in the bottom of the pit) and a special inspection
well-shaft.
The drainage pipe is laid at the bottom of the pit along the entire perimeter with a slope to
the shaft. Minimum well diameter d315mm. It must be installed below the base level (500mm), on
crushed stone- rubble and isolated from natural soil using a geotextile coating.
Fig. 3 Drain pipe