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FEATURES
Things down the drain (Part 1)
Having spoken with several plumbers in the industry, a few
common questions arose around drainage.
By Benjamin Brits
Drainage is something that most people do not even think
about; yet, it is vital, as drainage allows the removal of
waste and wastewater, creating a safer and healthier
environment for us to live in.
Looking back over history, we can all appreciate the need for
proper drainage systems. If you had to imagine yourself as a settler
in a new village in ancient times and you happened to be one of the
less fortunate, you would typically find yourself at the foot of a hill.
Now, you may not think that is such a bad thing.
Well, the more well-to-do you were, the higher up the hill you would
be, and on top of the hill would be the people who are considered
our affluent citizens in today’s times. The reality is that in those days,
there was no such thing as a drain, a sewer, or a stormwater pipe.
A typical
drainage
installation
for a public
restroom.
The common way to dispose of your waste was through a
hole in your floor; this included old food, urine, and faeces.
This would then pile up under the houses, attracting all
sorts of pests and, of course, was a perfect breeding ground
for diseases. Now, when the rains came, the natural thing
happened: all the waste would be caught up in the stormwater
and flow down the hill, around and then potentially into the
houses below. You can see how this would be a ghastly
way to live, especially for the poor at the bottom of the hill.
Unfortunately, South Africa still sees these sorts of living
conditions in the informal settlements and rural areas.
Fortunately, in those days, it didn’t take too long before
channelling methods were developed to at least control where
and how the waste was handled, albeit still open systems,
as people would regularly become gravely ill and die, due to
these unsanitary circumstances. It is amazing to know that the
materials used (short of a few that have been discovered to be
deadly) can still be found in current drainage and sewer systems.
These materials were terracotta, clay, lead, and bronze; the
Egyptians were fortunate to discover copper as early as 500BCE.
Getting back to 2019, we answer some of the questions posed to
Plumbing Africa pertaining to how things work nowadays. Please
note that references are made to specific standards, but not all
the details can be included in this article, as it covers too vast an
amount of information.
WHAT ARE THE CORRECT STANDARDS FOR ABOVE-GROUND
AND BELOW-GROUND PIPING AND INSTALLATION?
Firstly, it is always best practice to apply all South African National
Standards (SANS) regulations pertaining to installations. Although
some will dispute that not all standards are compulsory, which
is indeed true if they are not part of regulations, standards have
been established not only for the sake of best practice, but also
to meet the requirements of the consumer in terms of product
performance and, most importantly, safety.
A sanitary drainage system design and installation by a plumber
must comply with SANS10400-P and comply with the deem-to-
satisfy rules. These rules must be closely followed to comply with
the regulations that specify the performance of the system; that is,
the system needs to function as it is supposed to.
There are only seven regulations and SANS10400-P, P2, specifies
the performance. A rational design (by an engineer) must comply
with the regulations. It is important that you as the plumber
know the rules and their application to meet the overall correct
functioning of the system. When a learner plumber is tested for
registration as per SANS10400-A, their knowledge of the theory
as per SANS10400-P is also tested.
April 2019 Volume 25 I Number 2
It is stated in SANS10400-A that the National Building Regulations
(NBR) is not a design manual, but this document contains all the
details on drainage; however, as you would know, it sometimes needs
clarification and the correct interpretations to be applied correctly.
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