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< prev - next > Disaster response mitigation and rebuilding Reconstruction PCR Tool 10 Quality Control (Printable PDF)
inadequate knowledge of the structural
performance of buildings in disasters. To prevent
this, structural engineers or suitably qualified
built environment professionals need to check
these documents, better yet, produce them
• Building materials and components passed as
fit for purpose when they have not been checked
adequately. It is important that materials and
components can be traced back to source if a
deficiency is discovered.
• Building materials or components not stored
or handled properly resulting in deterioration
or damage; it is particularly important to keep
cement dry, to keep aggregates free from
contamination (by wind, animals, children etc),
and to protect timber from excessive sun and
• Builders lack the technical skills to undertake
the construction properly. It is important to
assess the technical skills of builders in the area
and to provide training to address deficiencies.
Competent builders can be issued with
certificates that show their level of proficiency.
• Site supervision may be lax. Supervisors must
be aware of all the construction jobs to be
undertaken. They need to be able to interpret
drawings and specifications or instructions
issued by professionals. They also must be able
to communicate clearly with the builders.
• Supervisors given too many house construction
sites to supervise. In post-tsunami
reconstruction in Sri Lanka, the upper limit for
a caseload was set at 100 houses, but some
technical officers had to deal with 130 in two
locations an hour apart; others were supposed
to visit 25-30 sites per day. Under such
conditions, supervision and support cannot be
• Builders take shortcuts to get a job done quicker
or reduce costs; sometimes home owners do
the same. This is particularly tempting when
construction uses expensive materials such
as cement or steel, a particular problem once
concrete or mortar has set as it becomes more
difficult to check its quality on site.
• Builders try to save in other ways, for example,
not adequately curing concrete, mortar or
stabilised soil whilst hardening, especially where
water is scarce, or by mixing excessively large
quantities of mortar in one go to continuously
use for hours by adding small quantities of
• Inadequate inspection of building sites.
Inspection is different from regular supervision
in that it tends to be done at intervals only,
often by an independent party. Its main aim
is to check whether the work is up to standard
and in order to approve instalments of
reconstruction grants. Inspectors may face other
problems which can mean that deficiencies get
overlooked: too many cases to deal with; lack of
transport; unwilling to risk confrontation, or may
themselves be corrupt.
• Whilst there tends to be ample information on
general construction, especially using modern
materials, there is less on disaster-resistant
building or on good vernacular construction.
That which exists may be of questionable
quality and not structurally verified. This lack of
information affects those involved at all levels of
safe building, from families to professionals.
Approaches to determining the quality
of reconstruction
There are a number of approaches that authorities
and agencies involved in reconstruction can
take to come to a decision on the level at which
quality control should be set. These range from:
adopting international standards; adhering to a
national regime already in place; setting regulations
specific to a national reconstruction strategy; or
allowing the people to decide on the desired level
of quality. In People-Centred Reconstruction, it is
important for those affected by disasters to have a
say in the quality of construction that is adopted,
as well as in the design and construction itself. If
other stakeholders set quality at alternative levels
that appear unachievable or unreasonable to the
affected peoples, it can subsequently become
difficult to obtain their interest and participation in
projects. The most appropriate approach to adopt
depends on the local context and therefore needs
to be decided on a case-by-case basis. The issue of
standards for reconstruction will be covered in more
detail in a future PCR tool.
Quality Control in practice
Ensure that building materials and
components used are of adequate quality
The use of materials that are poorly produced
or inadequate for the intended purpose can be
a significant factor in the collapse or damage
of buildings in natural disasters. This can be a
particular problem with materials produced by
small enterprises, often in the informal sector,
or those produced or gathered by residents
themselves. As it is difficult to ensure the quality
of materials produced in a decentralised way, some
programmes consider pre-fabricating them in a few
central locations where support and supervision
can be provided regularly. However, even materials
produced by larger formal enterprises may
sometimes be sold without adequate checks,
especially in the absence of national material