Selecting stones with Bellstone & Slate
Stone is a beautiful and time honored way to adorn a
home or commercial building but stone by its very nature is variable in
colour, texture and quality.
These characteristics make stone attractive as a building component but
they can be beguiling as well because the vast majority of people cannot
distinguish good quality stone from poor.
The durability of stone is determined by its strength and its capacity to
absorb water both of which can be tested for. Good dense, hard stone that
has low water absorption properties will be far more resistant to weathering
if used outdoors and will be more resistant to salt attack if used around
swimming pools. Stone with these qualities will also be less likely to stain,
so maintenance costs are lower.
Sandstone is frequently used in outdoor applications such as swimming pool
surrounds and recreation areas where the stone may be subjected to salt and
chlorine attack from the swimming pools, food and drink stains from BBQ areas
and even biological stains from dirt and leaves. The water absorption properties
of different sandstones are often assumed to be similar whereas tests reveal
huge variation.
The best performing sandstone may only increase its weight by 1% when inundated
with water but some sandstone will be as high as 12% - the latter being
inappropriate for use as outdoor paving unless repeatedly sealed.
The problem for the consumer is that unless they have experience in evaluating
stone it is unlikely they will be able to differentiate good quality from bad.
Buying beef at a butcher shop carries the same risks - you need to eat it first
to assess quality.
Stone like beef, battles with a generic price tag that hides a huge range in
quality. Thankfully beef is being tested (Meat Standards Australia), branded
and packaged and comes with guarantees and the most professional suppliers of
stone are making similar efforts to help consumers identify superior quality.
There are Australian standards for the flexural strength, water absorption,
slip resistance and resistance to salt attack for all types of stone including
sandstone (ASTM616) - these standards are the consumers best friend providing
they can find a supplier that displays recent test results.
Bellstone & Slate P/L are Sydney based stone and slate specialists who routinely
test all stone flooring products to ensure product safety and durability. For
example, Willow sandstone, their most popular range of sandstone absorbs only
2.2% water whereas the standard is 8%; it is a strong (dry flexural strength 19.4
MPa), dense (bulk density 2421 kg/m3) stone with the highest slip resistance
rating (wet pendulum 56V) and excellent salt resistance characteristics (weight
loss 0.2% with no visible decay).
Indicative data such as this provides consumers with confidence to use a stone
tile or paver for its intended purpose without taking unnecessary risks. Objective
information on stone also empowers consumers when making important purchasing decisions.
Bellstone & Slate P/L provide all known test results on their stone tiles, pavers
and cobbles on their web site http://bellstone.com.au/test_results.htm
For further information contact:
Bellstone & Slate
phone: 02 9630 3307
fax: 02 9630 3348
web: www.bellstone.com.au
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