2. Infrastructure Development in Africa/Ghana
The State of Ghana’s Infrastructure
Housing Delivery in Ghana
Dampness in Residential buildings
Threats of Rising Damp to Housing Delivery in Ghana
Current Research Findings and The Way Forward
3.
4. •Africa has enjoyed significant social and economic progress over the
past 15 years (African Economic Outlook, 2015).
•Infrastructure deficit has undermined all the efforts towards achieving
sustainable development and structural transformation in Africa.
•The development of a large middle class estimated at nearly 350
million in 2010 is driving the demand for socio-economic
infrastructure including access to water and sanitation.
5. •Structural transformation and industrialization require adequate
infrastructure to power economic activity, fuel industrialization,
connect producers to markets, enhance intra-African trade and foster
regional integration.
•Projections by the Office of the Special Advisor on Africa, OSAA, (2015),
shows that:
Power demand will rise from 125 gigawatts (GW) required in 2010 to 700 GW by 2040;
Transportation volumes will increase by up to 6-8 times and even higher for landlocked countries;
Port throughput will rise from 265 million tonnes in 2009 to 2 billion tonnes in 2040; etc.
6. •Africa’s infrastructure has lagged behind others in developing world
because:
Approximately 60% of the continent’s population lacks access to modern
infrastructure;
Only 38% of the continent’s population has access to electricity;
Less than 10% internet penetration rate;
75% of Africa’s road network is unpaved and poor port facilities add 30-40% to
intra African trading costs and FDI.
7. •Bridging the infrastructure deficit imposes itself with urgency to
provide:
Buildings; roads; railways and ports; information and
communication technology; energy facilities and health facilities;
and the management of water.
•African leaders have made infrastructure development a pillar of the
development strategy of the continent which is anchored on regional
integration and the realization of the African Economic Community
enshrined in the 1991 Abuja Treaty.
8.
9. •Infrastructure contributed just over 1% to Ghana’s improved per capita
growth performance during the 2000s (Africa Infrastructure Country
Diagnostic Report, AICD, 2010).
•Despite Ghana’s success with increasing access to infrastructure
services, the quality of service remains low (AICD, 2010).
•Ghana’s most pressing challenges lie in the power sector (AICD, 2010).
10. •With respect to regional integration, Ghana is maintaining its
international road corridors but lacks power and ICT connectivity with
its neighbors (AICD, 2010).
•As the country approaches the middle-income threshold, it will need to
focus on upgrading its infrastructure indicators in line with this
benchmark (AICD, 2010).
•Addressing Ghana’s infrastructure challenges will require sustained
expenditure of almost $2.3billion per year over the next decade (AICD,
2010).
11.
12. •The housing situation in the world is at a crisis level and remains one of
the global problems (Ademiluyi, 2009).
•Rapid growth in population and urbanization, especially in Africa has
resulted in sub-standard housing conditions, overcrowding of
households, inadequate and unreliable infrastructure and services
(Tibaijuka, 2009).
•Housing is one of the most widely discussed issues on the agenda of
both past and present governments in Ghana.
13. •Ghana, like many other developing countries, is facing an acute
shortage of housing.
•There are about 5.8 million dwelling units in Ghana, less than half of
which are classified as houses (GSS, 2010).
•Whereas the country’s population is increasing at a rate of 2.7 per
annum, the increase in housing stock is unable to keep pace and the
situation is worsening.
14. •Ghana had a housing deficit of one million units as of 2009 that will
double in the next decade if the status quo is maintained (GSS, 2010).
•Ghana is expected to put up 2.5 million housing units by 2025 if it is to
meet the housing needs of the populace, about 150,000 per year.
•The supply capacity nationally is said to be currently hovering around
42,000 units per annum.
15. •Thus 70 per cent of the national requirement remains unsatisfied each
year.
•Despite these shortfalls in the housing delivery, most of the existing
dwelling units are sick, suffering from various forms of defects. Key
amongst which is rising damp.
16.
17. •The penetration of water through the walls and certain
elements of buildings (Halim et al., 2012).
•An excessive moisture
contained within building
materials and components
(Hamid and Ngah, 2010).
21. Sources of dampness in buildings have been extensively studied
Hollis
(2002)
Rising
Dampness
Penetration
Dampness
Condensation
Pipe Leakages
Burkinshaw
and Parret
(2004)
Condensation
Penetration
Dampness
Leakages
Below ground
sources
Site/Building specific
22.
23. •A study was conducted in Ghana to identify and diagnose
the lead source of dampness in residential buildings and
recommend suitable treatment mechanisms to control such
problems.
•The lead source of dampness was identified to be rising
damp.
•Five thousand and thirty 37 (5,037) out of 5,800 buildings
surveyed demonstrated symptoms keenly related to rising
dampness.
24.
25. •It is the most frequently encountered cause of damage to
masonry walls.
•It results from the capillary flow of water from the
ground (Oxley and Gobert, 2011)
•Ground water reaching the foot of a wall which tends to
rise in the walling material and continues to do so
due to capillary action to varying degrees
of intensity (Melville and Gordon, 1998).
26. •Caused by a natural phenomenon called capillary action.
•Ground water is drawn vertically upwards through fine
pores in a material.
27. •Majority of construction materials are porous
•They may be embedded in, or be in contact with the ground,
and they will encourage the migration of water from the
ground by capillary action.
28. •For water to rise in a wall, a supply
must be available at the base.
•If the ground surrounding the wall
is saturated this condition is
achieved.
29. •If the ground is not saturated, the soil will exert a suction
that will oppose the upward capillary pull on the water in
the wall.
•If the water table falls, the height of the moisture in the wall
will drop to a new level provided there is sufficient time for
equilibrium to become established
•Each period of heavy rain on the ground at the base of the
wall will produce a temporary condition of saturation and
the water level in the wall will begin to rise again.
30. •The extent to which a wall is affected by rising damp differs
and is dependent on:
The level of moisture in the ground
The features of the wall enabling or restricting evaporation from its surface
The porosity of the material; and
The chemical composition of the migrating water
31. •In masonry that is affected by rising damp,
moisture is continuously transported upward
through the capillaries.
•The water evaporates on the surface and
more moisture follows.
32. •This process leads to an increase in the concentration of
salts on the surface.
•Most evaporation takes
place in the area between
the dry (top) and the damp
part of the wall (bottom).
33.
34.
35. •Salts in buildings are either :
•Efflorescence is a deposit of soluble salts which usually appears as a
fine, white crystalline powder on the surface of masonry as the
internal water evaporates.
present in the masonry during construction or
are absorbed from the atmosphere or ground water during the life of the
building (Jordan, 2001).
36. •The water which is transported into and through a wall, contains salt.
These salts can have different sources:
Salts are present in the ground.
Salts are also present in the brick/block itself, and can be dissolved by the
rising damp in the masonry.
They can be dissolved in ground water or ground moisture and
can then be transported with the ground water into the wall.
37.
38.
39.
40. •Mainly caused by bridging
of existing damp proof
courses and membranes
installed in buildings.
•Bridging is caused when
water by-passes damp
proof courses which are
installed in buildings.
41. Most common form of bridging is:
When the ground level outside a solid wall becomes higher than the installed DPC
42. Most common form of bridging is:
Internal plastering and external rendering extending down over the DPC line
43. •If soil or paths are allowed to touch the wall
above the level of the DPC, ground water will
be in contact with the wall and rising damp
can occur.
44.
45. •In a tropical region like Ghana
characterized by high rainfall with
relatively high and even
temperatures, rising damp is a very
common problem among many
public and private buildings.
46. •Studies carried out have shown that
rising damp has assumed an
alarming dimension in buildings in
Ghana.
•One out of every ten buildings is
affected by the problem, some of
which are visible.
47. •Generally, the level of awareness of
the problem among building
occupants and construction
professionals in Ghana is very high.
•This has led to the adoption of
various methods such as the tiling
of wall bases, re-plastering among
others to control the problem.
48. TILED WALL BASES
•The significance of the problem is
also reflected by the diversity of
products on the Ghanaian market.
TERRAZZO USED TO CURE RISING
DAMP
TILED WALL BASES
64. •Stephen Boniface, former
chairman of the construction
arm of the RICS, told the
institute’s 40,000 members
that ‘true rising damp’ is a
myth and chemically
injected damp-proof courses
(DPC) are ‘a complete waste
of money’.
65. •Elaine Blackett-Ord, chair of
the Register of Architects
Accredited in Building
Conservation, has also
spoken out against rising
damp, saying it was as rare
as ‘rocking-horse shit’.
66. •Jeff Howell, a qualified
bricklayer and author of
The Rising Damp Myth
(2008) said trials in the
laboratory confirm the
falsehood.
67. •Terry Brown, of GMW
Architects, said: ‘Of course
there is no reason why
inherited conventional
wisdom shouldn’t be
challenged. [But] the
challenge has to be scientific
and not anecdotal.’
68. •Recently in Ghana, studies have been conducted on the problem of
rising damp.
•The study first of all aimed at identifying and diagnosing the lead
source of dampness in residential buildings in Ghana and
recommended suitable treatment mechanisms to control such
problems.
69. •Among the objectives set were:
To identify the lead source (most dominant type) of dampness in walls of residential
buildings in Ghana;
To conduct laboratory diagnosis of the lead source of dampness in walls of selected
residential buildings; and
To explore treatment mechanisms to control the lead source of dampness through
field trials.
73. THE WAY FORWARD?
•Rising damp truly exists and is already staying with us.
•This issue is still an open challenge as indicated by Eliza Franzoni (A
renouned Building Pathologist and an Assistant Professor at the University of
Bologna, Italy).
•WHAT IS THE WAY FORWARD IN ACHIEVING SUSTAINABILITY IN OUR BUILT
FACILITIES WITH REGARDS TO RISING DAMP?
