metamorphic roofing slates
|In July 2004 a European standard
for roofing slates was published - BS EN 12326-1: 2004 Slate and stone
products for discontinuous roofing - Part 1 Product specification. This
standard replaces all previous standards throughout Europe including BS680
|The product specification is mainly
established against a series of tests described in BS EN 12326-2: 2000
+ A1 Slate and stone products for discontinuous roofing - Part 2 Methods
of test. The A1 indicates that it includes amendments dated July 2004.
|Any manufacturer claiming conformity
with the product specification must carry out the tests (relevant to their
product) described in Part 2 and make the results available in a prescribed
format (Acrobat file). This report (the official terminology is 'accompanying
commercial document' ACD) is in two parts. The first part includes information
about the manufacturer (producer), the slate source and the testing together
with the test results. The second part explains the meaning of the tests
and what is required for conformity to the standard. It is included because
some of the tests have different levels of conformity (indicated by a code:
S1, T3 etc) and others have varying requirements depending on the fundamental
properties of the product. One example of the latter is the minimum thickness
of the slates in relation to the strength of the slate rock from which
they are made. It is included to help specifiers and purchasers to understand
what they need from a slate and to ensure they get it. The ACD is not complete
without both parts.
|Because the standard contains several
different levels of conformity which relate to the different durabilities
acceptable in different countries and methods of slating, contractual specifications
for roofing slates will need to be more sophisticated than in the past.
It is no longer sufficient to specify ‘slates which conform to the relevant
British Standard’ or even ‘slates which conform to BSEN12326-1’. Such blanket
specifications would allow slates to be supplied at the lowest conformity
level within the standard and this could mean a life of perhaps only 40
|Strictly, a manufacturer claiming
conformity to the standard should supply a copy of the ACD with every consignment.
However it seems to me to be reasonable that they should make copies available
on their website. They will, of course, need to include a separate copy
of the first part (the test results etc) for each product because they
will have different properties such as thickness.
|For a full understanding of the
product specification and the test methods you should read the standards.
Copies are available from national standards organisations. In the UK contact
or their agents. On the BSI website search for 12326-1 or -2