Marble quarries above Carrara, Italy.
The surface finish will affect the slip resistance test results – a
sandblasted face presenting the least potential for slip and a highly
polished floor the most. If there is heavy footfall on the floor, even if
it begins as honed, it may end up as polished with time and footfall.
Therefore, abrasion resistance test results will help to understand the
likely wear capability of the floor. Results are expressed in mm and
BRE guidelines suggest anything under 23mm of wear is suitable for
intensive use, 23 to 30 medium use, 30 and above domestic use.
You will need to understand the predicted footfall to decide which
category your floor falls into.
Floor loading is another factor to consider. Floors that are expected
to carry the weight of cars, for instance, will require a stone with
a high flexural strength and possibly thicker than you would have
expected, to carry the additional load, however infrequent.
Flexural strength and slip resistance results can be found on the
CE marking certificate, which should be obtained from the supplier
of the stone. As long as we are in the EU it is their responsibility to
provide this to the buyer. Abrasion resistance tests do not have to
be declared on the CE certificate for external or internal floors, but I
would suggest these are checked before specifying the stone.
Book matched shower wall.
SLIP AND ABRASION RESISTANCE VALUES.
Slip resistance tests were originally developed as a rubber pendulum
test by the Greater London Council, published in 1971. Today, a
4S pendulum test is recommended, with a 96 hardness rubber to
simulate ordinary pedestrian foot traffic for public areas and 55
hardness rubber to simulate bare foot traffic - more suitable for pool
surrounds and wet bathroom floors. The HSE expect a minimum
value of 36 in the wet or dry, as I suspect will you or your client’s
insurance company.
There are coatings on the market that claim to improve a stone
floors slip resistance. But always check the on-going maintenance
requirements, the costs and any warranty offered.
Then there is underfloor heating, sub floor preparation, waterproofing
and installing the stone……..
Stone is a fantastic product and elevates design to a luxury level.
Just make sure you do your homework on the where the what and
the how.
Robert Merry is a member of the Technical Committee of the Stone
Federation of Great Britain. His company, The Stone Consultants, are
an independent stone consultancy who offer advice and guidance on
stone related issues to the construction industry including technical
specifications and expert witness.
www.stoneconsultants.co.uk
M:07771997621
E:[email protected]
Quarter book
matched floor.