SA Affordable Housing May - June 2020 // ISSUE: 82 | Page 15

ROOFING COMPLIANCE -ADVERTORIAL
Reduce energy costs and improve
comfort in metal buildings
Compiled by Saint-Gobain
At a time when the combination of efficient metal buildings, sustainability
and minimising utility costs are all hot topics, one of the best ways to
achieve in these areas is to install the correct thermal insulation.
With increasing pressure to improving on a metal
building’s envelope, it is crucial to consider how
performance, techniques and sustainable products
can support energy conservation. One of the most costeffective
ways of achieving optimal energy efficiency is by
installing efficient and appropriate insulation. This will
ensure the metal building performs as required throughout
its lifespan.
As effective insulation retains heat in winter and reduces the
need for cooling in summer, an upfront investment in insulation
results in reduced energy costs and enhanced comfort for
occupants. Depending on the design of the metal building, this
insulation will reduce the output requirement of mechanical
ventilation systems. Which is an additional cost saving!
SHORT-TERM PAYBACK
Insulation generally contributes to less than 1% of a project’s
building cost, with a payback within two years. When properly
installed in a metal building, glasswool insulation is proven to
save as much as one hundred times the amount of energy
consumed in its manufacture, transport and disposal.
The most common method of installation for metal
buildings involves placing insulation over roof purlins under
metal roof sheets and including side cladding. The roof
sheets are normally installed concurrently with the
insulation in one operation.
It is important for developers and contractors to be aware of
the individual specifications of various insulation products.
According to Ben de Freitas, Isover business development
manager, Technical Insulation, there are a few considerations
to take into account when selecting thermal insulation for
metal buildings:
When correctly designed and insulated, a lightweight wall
system will offer the same or better thermal properties than a
conventional brick and mortar construction.
Cost versus performance should be a key element when
specifying an insulation material. Select a well-known insulation
brand that meets the technical requirements of residential,
non-residential and technical markets. Isover produces various
insulation product types to suit a wide range of applications,
such as metal buildings, walls and roofs, floors, and HVAC
systems – all of which perform best when optimally installed.
Since the publication of SANS 10400-XA in 2011, there have
been numerous claims about the performance of different
insulation materials. One should consider sound scientific data
and take a holistic view before making a final decision on
insulation materials.
SAINT-GOBAIN
Always consider fire safety when specifying insulation for
specific building types. Choose insulation materials that adhere
to the local fire regulations. Better still, choose materials that
are non-combustible and will have no limitations to their use in
all building types or classifications.
Insulation is not a one-size-fits-all solution. There are
different parameters that need to be taken into account
depending on the desired outcome. Some insulation materials
have good thermal properties but lack good acoustic
performance. Others provide a good aesthetic finish but do not
have optimum fire performance. A product like Isover’s
Factorylite installed correctly in metal buildings provides
excellent thermal performance, is non-combustible and due to
its fibrous nature, has excellent acoustic properties.
INCREASE R-VALUE
Thermal resistance, known as R-value, is the measure of
resistance to the flow of heat through a particular thickness of
material. The higher the thermal resistance, the lower the
heat loss or heat gain of the particular building. One of the
most cost-effective ways to increase the R-value, is simply to
increase the thickness of the insulation. To put this into
perspective, a standard 50mm brick wall with a cavity gap has
an R-value of 0.11 m2·K/W (U-Value of standard brick wall
with cavity gap is 1.6 W/m2K (
The building sector accounts for more than 50% of South
Africa’s energy consumption, more than 30% of solid waste
generation, 5% of water consumption, and around four tons
of greenhouse gas emissions. It is clear that insulation plays a
critical role, but it has to be correctly installed by industry
experts.
www.saaffordablehousing.co.za MAY - JUNE 2020 13