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GYPSUM BOARDS
WHAT IS GYPSUM?
Gypsum is calcium hydrous sulphate (CaSO42H2O)
with a chemical composition of approximately SO3-46.5%,CaO-32.6%,water
of crystallization-20.9%. Typically occurs as rock gypsum, salenite,
alabaster satin spar.
OCCURRENCE
We see the mineral
gypsum almost as part of our everyday life. This versatile
mineral is the only natural substance to get back its original chemical
composition and solid form after the addition of water. The minerals
information page of USGS is
exhaustive and is a must for any serious reader. Plaster of Paris as
well as the usage of gypsum in the agricultural sector is well known.
Cement industry uses gypsum for improving the setting time of cement.
This article examines some aspects of its use in the making of gypsum
boards.
TYPICAL USE
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Gypsum wallboard systems,
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gypsum blocks
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spray able plaster intended for construction, finishing, new
buildings and renovation.
Additional information:
Gypsum usually occurs with contaminations and therefore calls for
careful mining. The threshold value for commercial gypsum is
generally at 75%gypsum. Mining of gypsum can be both surface and in
certain cases underground methods. The occurrence is widespread but
the major producers are Australia, Bahamas, Canada and Mexico. North
America tops in utilization and the largest gypsum quarry is in Nova
Scotia, Canada.
USGS survey of the mineral industry comes out with downloadable
statistics on gypsum as well as data on world production,
reserves and resources. Gypsum synthesis has
very interesting information about gypsum boards and is recommended
for anyone looking for additional information.
WHAT ABOUT SYNTHETIC GYPSUM?
Gypsum is one of the bulk minerals which when not available naturally is
made synthetically. And the synthetic gypsum has its followers and is
becoming increasingly acceptable. Mostly a by-product, it is attractive
to produce synthetic gypsum. Synthetic gypsum in certain cases is
replacing mineral gypsum gradually as is evident from Temple's plans. Synthetic
gypsum accounted for 15% of total demands. Temple has
details about formation of synthetic gypsum with diagrams. Synthetic
gypsum nowadays finds universal recognition particularly where natural
gypsum has its constraints. When Temple considers increasing its
utilization of synthetic gypsum for wallboards from its present level of
30% to even 80%, the role of synthetic gypsum can be visualized.
THE GYPSUM WALL BOARD
The gypsum wallboard being economical and fire-resistant has found a
niche in the building industry and has been around for more than 50
years in one form or another. Basically gypsum board is a loose name
applied to sheet products consisting of a core of non-combustible
material like gypsum and a paper exterior surfacing. Since these boards
undergo complex chemical and physical changes under watery conditions, a
very strict code is applied and regulated. The boards are continuously
researched and updated and subjected to technological advances and find
their way in a variety of applications.
The Northwest Wall and Ceiling Bureau (NWCB)
is an international professional trade association serving a wide
ranging membership of contractors, manufacturers, dealers (suppliers,
distributors) and labor.
Would you like to know how gypsum wallboard is made? There may be no
need to beyond National
Gypsum .
Some important producers and locations.
Lafarge Corporation is one of
the major North American producers of gypsum wallboard. Lafarge North
America markets a varied range of gypsum wallboard for all types of
buildings, whether domestic or commercial. It is also a benchmark
product for the renovation sector. Lafarge North America products
are used for partitions, interior walls, ceilings and floors.
British Gypsum
The product range include plasterboard, accessories, decorative
products, fire protection boards & systems plasters metal components,
ceiling tiles, acoustic & thermal mineral wool insulation, wall, floor,
ceiling & encasement systems.
Japan Gypsum Board
This is the place for contacts for gypsum products in some of the Asian
sources.
Gypsum in Gulf
The scenario in Gulf on Gypsum boards and resources.
GYPSUM ASSOCIATIONS
Gypsum Association established in 1930 represents manufacturers
of gypsum boards in USA and Canada providing information and assistance
to the construction industry. Links to major producers are available at
their site American Gypsum, Celotex,G-P gypsum, James Hardle Gypsum,
Lafarge North America, National Gypsum, Pabco Gypsum, Temple, USG,
Westrox etc.
RESOURCES
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Gypsum Association has
posted topical
technical papers. These topics are regularly updated and
call for regular look ins. The papers are a very useful resource for
anyone to go into details and nuances of gypsum wallboard usage and
issues connected with it.
Downloadable brochure- key
to a quiet home in PDF
Gypsum board and Rock-Lath -Resource
for details on installation, lamination, lead lining and bonding.
The installation diagrams are very useful.
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Recycling - Andela
Products supply recycling systems throughout the world and provide
details about the equipment for recycling Gypsum board. The
photographs of the equipment provide visual impact.
Additives are added to
reduce drying costs by reducing the water content of the stucco.
Here is a source for anyone who may require further details.
Thickness codeR-702-3 for
Gypsum board-useable chart. This is a very useful resource to check
requirements for a project. The function of the Building Inspection
Department is detailed here. The resources further include details
for obtaining a building permit, details on various parts of a
building and even a sample site plan in PDF .
Grab this safety
data sheet in PDF. The links provide further resources
and British Gypsum has come out with very useful data.
OVERVIEW
Synthetic gypsum is increasingly replacing mineral gypsum and this
forebodes well for the wallboard industry. The issues of sagging and
thickness have been addressed and progressively gypsum boards are
finding very wide application base. There are already definitive
guidelines, technical assistance and information base. The role of the
Gypsum Association and information dissemination of major producers has
brought about an increasing awareness of the gypsum wallboard
application.
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