BY: JOSHUA AYARKWA

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

• 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.

• 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.

• 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.

• 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.

• 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).

•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).

• 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.

• 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.

• 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.

• 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.

• 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).

PHYSICAL EFFECTS

• Timber rot

•Water staining

• Electrics made unsafe

• Cyclic wetting/drying

PHYSICAL EFFECTSCHEMICAL EFFECTS

• Efflorence

• Corrosion of ferrous metals

• Loss of cohesion

• Chemical attacks

PHYSICAL EFFECTSCHEMICAL EFFECTSHEALTH EFFECTS

• Ambient air conditions

•Mould growth and spores

• Viruses and infections

• Rot and infestations

Sources of dampness in buildings have been extensively studied

Hollis (2002)

Rising Dampness

Penetration Dampness

Condensation

Pipe Leakages

Burkinshawand Parret

(2004)

Condensation

Penetration Dampness

Leakages

Below ground sources

Site/Building specific sources

• 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.

• 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).

• Caused by a natural phenomenon called capillary action.

• Ground water is drawn vertically upwards through fine

pores in a material.

•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.

• 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.

• 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.

• 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

• 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.

• 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).

• 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).

• 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.

•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.

Most common form of bridging is:

When the ground level outside a solid wall becomes higher than the installed DPC

Most common form of bridging is:

Internal plastering and external rendering extending down over the DPC line

• 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.

• 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.

• 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.

• 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.

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

Dryzone technology

Bailey damp proofing co.

• 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’.

•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’.

•Jeff Howell, a qualified

bricklayer and author of

The Rising Damp Myth

(2008) said trials in the

laboratory confirm the

falsehood.

•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.’

• 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.

• 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.

CONTROL WALL

WALL WITH CONCRETE BASE

RESULTS FROM PROPOSED TREATMENT

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?