HKIE Veneree Club
16 April 2014
Realizing Economic Value via
Voluntary Work– A case Study of
Residential Seepage
By YL Choi 蔡宇略
Hong Kong Former Senior Civil Servants Association
and
Hong Kong Academy of Engineering Sciences
Engineering (in contrast to
Military Engineering)
“the art of directing the great sources of power in
nature for the use and convenience of man..”
---Economic Value
How Do Engineers Create
Economic Value?
Provide new works to enable new activities.
(Quantitative enhancement)
Improve existing methods of production or
operation. (Quality ebhancement)
Design new types of works toopen up new types
of activities. (Quantum jump)
Prerequisite of Realizing Economic
Values
Investing in new infrastructure
Protection of intellectual property rights
Removing regulatory obstacles to innovation, new
design or improvements
Willing acceptance of stake holders
What can Retired Engineers offer?
• Retirees = large, diversified knowledge &
experience
• Fruitful engagement economic & social
benefits through new design or
improvement to current process
• Difficult to identify projects
• Ways & means of engaging retirees only
beginning to develop (Active Aging)
Integrating Professionalism with
Volunteerism
• Knowledge Identify deficiency of current
practice Propose improvement Potential
economic value
• Volunteerism No vested interest Public
acceptance Realize economic value
• Case study—Investigation of water seepage
in residential buildings
Changing Nature of Residential
Seepage Problem
• Before 1970—Mainly rainwater infiltration,
• Since 1970—Leakage in water & drain
pipes,
• Since 1980—Seepage under unauthorized
bath/toilet,
• Since 1990—Seepage becoming significant
among new buildings,
• Since 2000—Becoming wide spread.
Rapidly aggravating seepage
problem
30000
25000
20000
Cases received
Cases handled
15000
10000
5000
0
2005
2006
2007
2008
2009
2010
2011
2012
Social & Economic Implications
of Water Seepage Problem
•
•
•
•
Adverse neighbor relation
Leading to social segregation in housing
Accelerate structural deterioration
Leading to premature redevelopment of
buildings
Current Practice of Investigation
• Joint Office (JO) of Buildings Department /
Food Environmental Hygiene Department is
vested with statutory power
• 2-stage dye tests—on drainage pipes, then on
floor of bath/toilet
• Assessment criterion—visual for 1 month, test
site taken as source if dye color is noted in
seepage water.
Performance of Seepage
Investigation by Current Practice
Results of Cases Investigated by JO up to
31/12/2012
Source identified
27,405 43%
Could not be identified
9,151 14%
Seepage ceased
27,234 43%
Total =
63,790
Source:Govt. Reply to LCQ8 of 20130320
Resolving water seepage problems
Inconsequential Effect of
Administrative Improvement
• Ombudsman 2008 investigation report on
JO performance—Management deficiency
identified
• Staff increase of JO—2011-12 staff
members: FEHD 219, BD 64 ; $35M.
(Source: Reply to LegCo questions)
• Audit report 2011—In 8 recent cases,
average period of inaction=44 months.
Engineering Deficiency of investigation
practice is likely!
Complex Case comprising 3
seepage incidents over 8 years
• Same seepage sites.
• Seepage at 2nd Floor unit (2F): 2006-2009;
2010 January-July; 2013 January-date.
• Seepage was intermittently visible at 3rd
Floor (3F) unit 2006-2013
• No sign of defect in 3F drainage, floor or
wall.
• Dye tests show no leakage of pipes in 3F.
Soil Pipe
Duct
Dye Test
on Soil
Pipe in
3F unit
Inconsistency of Dye Tests
on Floor–Incident 1
• 2007 March dye test in 3A: dye noted in 2F
14 days after test. JO suspected 3F to be
source according to current practice.
• Suspicion contrary to fact—3F toilet NOT
used in 2007 March to June
• Retested in July 2009—NO dye noted
• Seepage dried up in September 2009.
Inconsistency of Dye Tests
on Floor –Incident 2
• 2010 March dye test in 3A: dye noted in 2F
10 days after test. JO alleged 3F again to be
source according to current practice.
• New method showed water intruding 3F
from ceiling.
• New test in June 2010—NO dye noted
• Seepage dried up in July 2010 in both units.
New Method of Finding Flow Path
by Moisture Scanning
Location of Hole in Downpipe
March 2014
Investigation of Incident 3
• Flow path identified by new method was
confirmed by opening up inspection hole.
• Dye test on vertical common down-pipe
confirmed leakage.
• Opening up of pipe duct located pipe
leakage points precisely.
• Anomalous dye test result on floor drainage
hole confirm diffusion causing false
indication of dye test.
Deficiency of Dye Test
--3 Levels
• Fundamental—Water tightness of test site
alone is unrelated to seepage site.
• Secondary—Dye transport mechanisms >
water flow
• Tertiary—Lack scientific basis of use of
observable dye concentration or 1-month
observation period as criteria.
Role of Professionalism in Identifying
Defect of Current Practice
• Common sense 1—a dry surface cannot be
seepage source. (Incident 1)
• General professional experience—Absence of
visible defect indicates unlikely infiltration.
• Hydraulic expertise—Dye test result actually
implies adequacy of waterproofing state.
(Incidents 1 & 2)
Role of Knowledge in
Improving Current Practice
• Common sense 2—Inconsistency of successive
test results must indicate that certain key
parameter is missing from the assessment
criterion in current practice.
• Hydraulic expertise—Identifying flow path from
moisture scanning results. Hence enable direct
identification of source
(Contrast with trial and error approach in current
practice)
Economic Value of New Method
• Reduce investigation time and disturbance
to residents
• Prevents steel oxidation & premature
building deterioration
• Help avoid unnecessary redevelopment and
indirectly help increase housing supply
Why New Method was not
Discovered Earlier
• Lack of knowledge. The necessary experience is
gained only over a long career.
• Economic value is not the concern of private
practitioner.
• Property developers has no interest in
improvement.
• JO did not recognize deficiency of current
practice
• Public is ignorant.
Conclusion
• Retirees possess a wide range of knowledge and
professional experience.
• Economic value of knowledge can be realized
through application to improve current
operational practice.
• Volunteerism provides the impetus to go through
the long process and to overcome various
resistances.
• It is in the public interest for Government to
create an environment conducive to engage
retirees in this new mode of voluntary work.
Thank you!
Y L Choi
16 April 2014