moladi superior building technology reduces high costs of conventional masonry construction
moladi superior building technology reduces high costs of conventional masonry construction
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moladi superior building technology reduces high costs of conventional masonry construction
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With
the population of the African continent expected to reach a staggering 2
billion people by 2050, almost twice the population number estimated in 2010,
it is a stark reality that every year, there will be more and more people
needing homes, over and above the current demand.
Although
the extensive and many complex difficulties, relating to the delivery of
affordable housing in Africa is well documented, the ever-increasing demand for
housing keeps mounting and continues to be a major concern. Projections by the
United Nations would indicate that 53% of Africa’s inhabitants would comprise
the urban population, of which 62% of city dwellers would reside in slums or
informal settlements. What’s more troubling is that it appears that the
incentive to move to the cities in Africa seems to be completely independent
from economic growth and development and this is not expected to ease in the
foreseeable future.
There
is no doubt that the challenge facing the continent is a colossus, but the
question is, whether conventional building methods are able to cope with the
ever-increasing demand for quality homes.
Throughout
history, man has become more sophisticated through technology; made
improvements on existing standards and norms, which have ultimately been determined
and developed according to the needs of the people. Perhaps the advances and
progresses in communication and transportation during the past two centuries
are the most evident of such improvement enjoyed by civilization. However, even
though the need for housing has always been a fundamental requirement to
sustain one’s health and welfare, the advances in this area have been somewhat
meager in comparison.
The brick and mortar method of
construction was recorded as early as 1458 B.C, which means that very little
has changed in terms of building structures over a period of almost 3.5
millennia. With the demand and requirement currently facing us as Africans, we
cannot expect to resolve the housing crisis in our age with a technique
developed for the requirements of society 3468 years ago.
One
such innovation is the award-winning Moladi building system, which looks at
incorporating green technology and sustainability to provide the best solution
to address the six key challenges that hinder the successful implementation of
low-cost housing projects in Africa; namely, lack of sufficient funds, shortage
of skilled labourers, lack of resources, work flow control, time constraints
and wastage. The Moladi construction system was founded in South Africa during
1986, and has been in successful operation for the past 27 years. Moladi’s
founder and designer, Hennie Botes, developed the innovative building
technology as a means to alleviate many of the cumbersome and costly aspects
associated with conventional construction methods without compromising on the
quality or integrity of the structure. According to Botes, “Moladi looks at
what has to be achieved now and builds on the knowledge and expertise of
yesterday in order to develop sound methods to exceed the needs and
expectations of ordinary people.”
The inefficiencies of moulding a brick or block in a mould then tasking an artisan to lay them
vs.
Moulded Construction System
The
Moladi building system involves the use of a unique modular removable, reusable,
recyclable and lightweight plastic formwork mould which is filled with an
aerated SABS (South African Bureau of Standards) approved mortar to form the
wall structure of a house in only one day. The process involves the assembly of
a temporary plastic formwork mould the size of the designed house with all the
electrical services plumbing and steel reinforcing located within the wall
structure which is then filled with a specially formulated mortar mix to form
all the walls of the house simultaneously.
The
Moladi formwork components are fully interlocking and are assembled into easy
to handle panels, weighing only 8 kilograms per square metre, which are
configured into a full scale mould of the desired structure. The formwork
panels are joined to form the external and internal walls cavities, producing
an ultimate wall thickness of 150 mm for external walls and 100 mm for internal
walls. All the steel reinforcing, window and door block-outs, conduits, pipes
and other fittings are positioned within the wall cavity to be cast in-place
when filled with the Moladi mortar mix.
All
Moladi structures have steel reinforced internal and external walls. The reinforcing
design is specified by an independent, certified Engineer; according to the
requirements of the structure, which is dependent on soil conditions such as
clay, expanding soils, collapsing soils, dolomite etc. The Engineer would also
take into account if the structure would be subjected to earth tremors, quakes
or hurricanes. As moladi structures are uniformly and cast monolithic, with
the reinforcing placed in strategic positions, this makes the building more
resistant to seismic movement.
The
Moladi mortar that is used to fill the wall cavity is essentially concrete
without stone. The mix design of the mortar is specifically determined by
laboratory tests that are carried out on local sand or aggregate, to ensure
that quality standards are adhered to. The density of the mortar will vary
depending on the sieve grading of the sand used, but will range between 1600 to
1800 kg per cubic metre. The Moladi mortar mixture produces a fast curing
aerated mortar which flows easily, is waterproof and possesses good thermal and
sound insulating properties.
A
compressive strength of between 15 and 30 MPa can be achieved in a 28-day
period, depending on the cement: water ratio. Under normal conditions the
mortar sets during the night (12 to 15 hours) and the formwork is removed the
following morning. There is no need to vibrate the mortar in order to achieve a
smooth finish.
At
the start of each project, local building material tests are carried out to
determine the unique mix ratios required to achieve the compressive strength
requirement of the walls, which is specified by the appointed project Engineer.
After
the wall cavities have been filled with the mortar, the mortar is left to set
overnight and the formwork panels are removed the following morning to be re-erected
on the next foundation. The wall has a smooth and flat finish that does not
require any plastering, beam filling or chasing.
The
result is a fast track cost effective and transferable construction technology
that is amortized over 50 re-uses, which reduces the cost of construction and
transportation significantly. This also facilitates the possibility for many in
situ structures to be built in just one day. It is essentially the simplicity
of its design and performance that contributes to the affordability of Moladi
homes which are roughly 30% less than similar structures built using the
traditional brick and mortar method.
Because
housing is a primary sector of industry that can contribute towards the
upliftment and empowerment of the unskilled and unemployed on a broad scale,
Moladi wishes to meet the challenge of alleviating the hardships experienced by
the millions of people in Africa who are fixed to the bottom third of the
economic pyramid through the use, training and application of Moladi. Its contribution
towards skills development in Africa could play a vital role in that the
application of the Moladi technology is not dependent on skilled labour or
artisans in its construction method and utilises local unskilled and unemployed
labourers to build Moladi housing units. This allows for greater community
participation and as more than 90% of the construction team on a Moladi housing
site consists of unskilled labourers, who are trained locally by a Moladi
foreman over a period of 2-3 weeks in order to transfer the required skills and
knowledge to complete the entire construction process.
The
training period is brief yet allows for a high standard of proficiency, as the
Moladi construction method has been designed with the objective to allow for an
unskilled team of people to follow Moladi’s optimized, repetitive and
sequential processes that eliminates the probability of any errors occurring
that are crucial to the outcome of the structural quality or integrity of a
Moladi housing unit. Yet another developmental milestone is that women, who
have traditionally been either reluctant or discouraged from working within the
male-dominated sector, are encouraged to participate in the non-labour
intensive Moladi building process. “The speed, affordability, quality,
adaptability, ease of construction, use of sustainable local materials and the
opportunity created to facilitate ‘sweat equity’ are key advantages that will
greatly improve the efficiency with which the world addresses the problems
relating to the world’s poor, homeless and unskilled communities.” says Botes
The
Moladi technology components are manufactured and produced in Port Elizabeth,
which is the 5th largest city in South Africa; a port city on the Indian Ocean
coastline and situated halfway between Cape Town and Durban. They currently
export their building system to over 20 countries worldwide, of which eight are
members of SADC (South African Development Community). Exporting Moladi to the
African market is relatively easy as it can be transported to virtually any
part of the world, including remote rural areas and informal settlements. An
added advantage is that Moladi is not restricted through the use of heavy construction
equipment and machinery in order to build with Moladi. Even the absence of
electricity would not hinder the building process.
In
recent years, there has been a steady increase in the development and
availability of alternative or innovative building technologies in Africa, such
as prefabricated building systems, from all over the world; many only hoping to
capitalize from the growing demand for affordable housing in the African
marketplace. Very few however have a track record which spans 28 years, or are
socially acceptable to the African market. What most often seems to be
overlooked is that, for most Africans, houses are also a reflection of their
societal and are considered more than a simple shelter. Botes says that Moladi
is able to accommodate any type of roof design or covering, any finishing
material, any type of window or door, so there are no limitations or
restrictions in terms of adapting Moladi to facilitate cultural design
preferences. Notwithstanding the aesthetics and social acceptance of the structures,
Moladi is accredited by numerous global building authorities and the building
method conforms to international building codes of good practice. It has also
undergone extensive testing by the South African Bureau of Standards (SABS) and
the University of Panama to ensure that the resulting structure is durable and
of the highest quality which has the key advantage of being able to withstand
earthquakes and cyclones as it is a monolithic structure. Commonly, Moladi
walls possess an average compressive strength of 15MPa or 15N/mm², which is far
stronger than the average standard for cement blocks which vary from 3.6 N/mm²
and 7N/mm² or common clay building bricks, which have a compressive strength of
5.2N/mm².
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| Appropriate Technology - the simplest level of technology that can achieve the intended purpose. |
In
its approach, Moladi brings to the field of construction all the benefits of a
factory assembly line; quality assured work by unskilled labourers at a maximum
rate of production with a high production output capacity. Yet, unlike many
manufacturing operations, the benefits of the technology are transferred and
spread to local communities through the purchasing, supply and utilisation of
local indigenous materials in its on-site production operations. All materials
used in the construction of Moladi homes, other than the formwork, are sourced
and supplied from within the local community to stimulate the local economy.
The
building materials required for the Moladi methodology are materials which are
readily available, easily accessible and sourced locally. “By utilizing
indigenous materials the benefits of the technology are spread to local
communities” says Botes.
The
selection and use of building materials relating to the Moladi construction
process is considered a crucial aspect in determining the environmental
sustainability of the Moladi technology. Although the calculation of embodied
energy is a complex matter and differs from region to region, building
materials used in the Moladi construction process have been carefully
considered according to the initial and recurring embodied energy that is used
or expended during the life cycle and operation of each material. Some
additional, but notable, factors which affect the overall energy consumption of
a structure – and which are often mismanaged within the affordable housing
industry – is the requirement for nonessential transportation, wasteful
packaging, plentiful waste of materials resulting from processing and
construction methods, and also poor dumping and disposal methods.
Materials
are rarely recycled or even reused and poor workmanship, the utilization of
substandard materials and the use of materials and components which have a
dissimilar and inconsistent durability, leaves the home owner with high a
maintenance home which requires frequent repair and even large scale
restoration. Lastly, passive design principles for the appropriate climate
which helps to minimize the energy required to heat, cool, ventilate and light
a building responsibly are largely ignored in favour of a cheaper initial cost
outlay. These factors are taken into account to ensure that Moladi buildings
provide environmental value by challenging members of the construction industry
who are quick to ignore the long term use and quality of a building in favour
of the short term saving enjoyed by the developer.
Of
the materials used in Moladi homes, steel has the highest embodied energy
rating of 44.66MJ/kg. However, steel is 100% recyclable and at the end of the
buildings lifespan, can be removed from the building with relative ease for
recycling. The steel reinforcing bars are essential for ensuring that Moladi
homes are durable and structurally sound to ensure that the home owner has a
safe and sturdy home which can withstand external forces. Plastic, the material
used for the Moladi formwork, has the second highest energy rating of Moladi
building materials at 43.03MJ/kg. The formwork however conserves energy due to
the fact that it is durable and does not require maintenance. The formwork is
re-used many times until it is eventually recycled into other durable household
consumer products and construction components. Moladi utilizes a closed-loop
policy with its plastic formwork so that none of the material goes to waste.
The Moladi mortar mix, has the lowest initial embodied energy rating, which is
1.4 MJ/kg. The operational energy of the mortar is further reduced by
eliminating excessive labour demands during the application of the mortar and
ensuring that the resulting superstructure is constructed efficiently and in an
optimized manner. The volume of Moladi mortar mix is accurately calculated to
ensure that no excess material is wasted. The durability and longevity of the
resulting structure requires minimal maintenance or repair work during the life
of the building. Clay brick, which is 5.12 MJ/kg, polystyrene, which is 117 MJ/kg,
cement plaster which is an average of 3.24 MJ/kg and Aluminium at 227 MJ/kg are
other common building materials utilized in other types of construction methods
which may be comparable to that of Moladi building materials.
All
materials used in the construction of Moladi homes, other than the formwork,
are sourced and supplied from within the local community. Specifying criteria
is critical in that the fixtures, fittings and service systems installed in a
Moladi structure have a durability term similar to that of the overall life
expectancy of the building. Other than contributing to the local economy, this
practice drastically reduces the need for additional and unnecessary transport
and handling of goods and building materials. By reducing the number of
operations required during the successful construction process means that there
is a less chance of the occurrence of errors, waste and rework. This follows
from the same logic that the fewer the number of operations, the higher the
quality of the product, resulting in a predictive timeline and ultimately cost
savings.
The
Moladi method of construction has been designed to efficiently produce
structures which have a long life, are durable and adaptable; homes which are
considerate of the environmental impact as well as the needs of the home owner.
The speed, affordability, quality, adaptability, ease of use, the use of
sustainable local materials and the opportunity created to facilitate sweat
equity are key advantages that would greatly improve the efficiency with which
the world addresses the problems relating to the world’s poor, homeless and
unskilled communities.
While
a building technology such as Moladi will not resolve all the challenges faced
by the African continent, it is clear that the use of a tried and tested and
socially acceptable affordable housing system will improve service delivery and
the lives of millions of poverty stricken families in Africa through its
innovation.
Keywords: moladi, building technology, building technique, new technology,
plastic formwork, African solution, rural development, new town development,
affordable homes, low cost housing, fast track, system, alternative building
technology, South African Bureau of Standards, Hennie Botes,
superior building technology, #SBT, revolution in building materials
