DESIGN: DEAR MR PLUMBER
61
The power of prevention
I have been working for 66 years and yet, I still learn
something new every day.
By Vollie Brink, Pr Eng
I was taught that the engineer must always assess
the risk factors and address it in the design. Much to
my amazement, a young representative of a piping
manufacturer recently said to me, “The engineer
must not make provision in the design to prevent
potential problems.”
The discussion was about the South African design
standard versus the EU standard for drainage in terms of
the horizontal branch and horizontal discharge pipes and
the fixtures that may be connected to it.
The South African standard, SANS10400-P, requires that
soil and waste horizontal branch pipes must be separate
and connect separately to the stack pipe. The fixtures of
an apartment are called a ‘group’, which typically consists
of a WC, washbasin, shower, bath, sink, and washing
machine, and these fixtures in the ‘group’ must all connect
one-by-one to the stack with at least 200mm c/c apart.
The fixtures of an ablution are called a ‘range’ and
typically consist of a number of WCs, washbasins, and
urinals (in the case of male toilets). These ‘ranges’ of
fixtures must also be connected separately, group by
group, to the stack pipe with 200mm c/c apart.
It is obvious that a WC cannot be connected to the same
horizontal branch pipe as the wastewater fixtures —
this makes good sense to “prevent a potential problem,
health risk, and nuisance”. This is clear “design to
prevent potential problems”, and good and responsible
engineering design.
There are other preventative design measures that can be
taken to prevent potential health risks and nuisance, such
as to provide for backflow prevention when a blockage
occurs downstream in the drain outside the building and
to prevent spillage inside the building, because a spillage
outside the building is better than inside the building.
A gully can act as a backflow overflow, but there are
other methods that would be a ‘cleaner’ solution,
aesthetically more acceptable, and also a method of
“design to prevent potential problems and mitigating
risk and nuisance”. If the designer ignores ‘potential
problems’ and there are consequences, then he/she
could be in serious trouble. There can be no ambiguity
www.plumbingafrica.co.za
around the seriousness of health and safety and what
everyone’s responsibilities in this regard are in the
latest OHS Act. The responsibilities of the manufacturer,
supplier, and installer are also clearly spelt out in terms
of the Consumer Protection Act, and if anybody wittingly
and knowingly chooses to ignore the potential risks
to health and safety, it will be regarded as a serious
matter with serious consequences.
When we talk about the ‘health’ element in the design
and installation, we are actually talking about protecting
or preserving health and mitigating potential problems,
which are serious matters that the manufacturer,
supplier, installer, and the engineer cannot ignore — and
specifically not to ‘save money’.
This young man argued with me and said, “It is fine if you
want to have separate branch pipes because then I sell
more pipes.” This reflects a complete misinterpretation of
the responsibilities in terms of the Consumer Protection
Act. It also shows a disregard for the health and safety of
the people who will occupy the building and the fact that
the engineer must mitigate and prevent problems in the
design and construction.
Vollie Brink
Vollie Brink is one of the
industry’s longest-serving
wet services engineers.
He continues to serve on
SABS committees and
has been involved in the
Green Building Council’s
Green Star rating
system. Brink continues
to consult for various
organisations while
enjoying a well-earned
retirement.
I have always maintained that the manufacturer plays an
essential role in the ‘chain’ of role players in the building
industry. I believe that the manufacturer must take note
of the responsibilities of the other role players and the
‘institutional’ requirements of the various countries
where they operate.
Role players in the ‘chain’ must respect one another,
from the institutional bodies to the last body in the chain.
A serious matter that we have to deal with in South
Africa at the moment and which we have to address in
the design, is the lack of maintenance and competence
to carry out maintenance. I watched a video on water
conservation in another country and the water engineer
said, “We fix leaking pipes and we also replace pipes
before it can leak.” This is responsible engineering and
preventing problems from occurring.
There are two types of maintenance: fix what is broken
and preventative maintenance. In South Africa, there is a
dire lack of ‘preventative maintenance’. PA
January 2019 Volume 25 I Number 1