How to anchors in accordance with supply BS 8539:2012

Ensuring best fixings practice
www.the-cfa.co.uk
How to supply anchors in accordance with BS 8539:2012
Code of practice for the selection and installation of post-installed
anchors in concrete and masonry. A guide for distributors of fixings.
1
Introduction
BS 8539 is arguably the most significant development in the use of construction fixings
since the advent of European Technical Approvals (ETA)1 in 1997. Its introduction was
prompted by a series of failures involving fixings, some resulting in injury and death. The
role of the distributor in such failures is not a dominant one but may be significant if, for
instance, the distributor gives advice regarding the suitability of a fixing which turns out to
be inappropriate or an alternative anchor is supplied to that specified and the full
selection process has not been carried out on the proposed alternative.
The BS sets out all stakeholders’ roles and responsibilities including those of the
distributor which are the least onerous of all involved. These responsibilities are in
addition to those required by legislation, such as the Construction Products Regulation,
etc., and those recommended by other standards.
This “How to” guide summarises the responsibilities of those who supply construction
fixings to any project where their use can be regarded as safety critical. In addition to
being familiar with their own roles and responsibilities distributors are advised to be
aware of those of the other stakeholders as they may be the first point of contact that
some have with the process so distributors are in an ideal position to make other
stakeholders aware of BS 8539. The other “How to” Guides in this series2 may be useful
in this respect.
1.2
Terminology
Terminology used in the code is based largely on that used in ETA, in ETAGs (the
Guidelines used to award ETA) and CEN Technical Specifications3 for anchors (fixings).
This has resulted in the adoption of some terms and notation not previously used in the
industry especially for loads now referred to as either a type of action (the load to be
carried by the anchor) or a type of resistance (the capability of the anchor to support the
action). This issue is important for distributors in that they need to be able to
communicate effectively and knowledgeably with all other stakeholders including
specifiers and testers who will all, at some stage, want to discuss loads. The code even
differentiates between the Designer - the person with overall responsibility for the
structure in which an anchor is located, and the Specifier - the person responsible for
selecting the anchor. For a detailed explanation of the differences between the new and
old terminology see4.
2
Responsibilities (BS 8539 Clause 4.1)
Anchor manufacturers and their agents i.e. distributors, are required to provide all
information for the specifier to select the correct anchor, i.e. technical catalogues and
software, and for the installer to install it correctly i.e. installation instructions.
The supplier is also required to supply the anchor as specified unless the change
management procedure referred to below has been followed.
CFA
“How to” supply anchors in accordance with BS 8539.
(Issue 2. December 2013)
1 of 2
Ensuring best fixings practice
www.the-cfa.co.uk
They should take the opportunity to ensure that all associated setting equipment is
offered to the contractor such as drill bits, hole cleaning equipment, setting tools, torque
wrench and sockets etc., in order that the installer can install anchors correctly.
Distributors are also in an ideal position to provide training in the correct installation of
anchors, or at least to facilitate this being provided by the manufacturer or specialist
training agency, in order that their customers can fulfil their obligation under the code to
use only competent installers.
3
Distributors’ role in selecting anchors.
BS 8539 sets out the process of selecting an anchor through selection of the appropriate
type before going on to determine the size needed to carry the required loads. While
many distributors will have enough experience to advise specifiers on the most
appropriate type of fixing, determining the size - in the case of safety critical applications
using anchors with ETA - is now such a complicated process that it can only safely be
done using software. Unless Distributors have staff specifically qualified to do this they
are best advised to gather the necessary design information and pass this to their
supplying manufacturer who will then come up with a recommendation. To assist with
these activities the CFA has designed a series of forms
available from the CFA website in a special section “CFA
8539 Forms” including Form 01 – Design information and
Form 02b – Anchor recommendation. They are part of the
“8539 Toolkit”, also with its own section on the website. The
BS, and these forms, make it clear that when suppliers of
fixings make recommendations they are not taking on the
responsibilities of the specifier.
4
Changing specifications. (BS 8539 Clause 10)
Distributors are frequently asked to advise on alternatives to specified anchors. While it
is entirely reasonable that distributors should use their knowledge and experience to put
forward suitable alternative anchors to those originally specified the code makes it clear
that any alternative should be subjected to the same rigorous selection process as if it
were the first anchor to be considered.
It is not enough to compare headline catalogue values or to carry out proof tests on site.
Neither of these approaches can be guaranteed to take into account the various factors
influencing the way performance changes as edge and spacing distances change.
Distributors should therefore enlist the technical support service of the manufacturer of
the anchor they propose as an alternative who should be able to provide all necessary
support to the specifier by way of technical data or software to enable the alternative to
be selected with the same confidence as the original. Again the forms listed above can
help with this process.
1
For more information on ETAs see CFA Guidance Note: ETAs and design methods for anchors used in
See How to select anchors (for specifiers and designers), How to install anchors, (for contractors and
installers) and How to test anchors – for testers. CFA website at www.the-cfa.co.uk .
3
Design methods for anchors with ETA may be contained in CEN Technical Specifications in the series
CEN TS 1992-4 Parts 1 – 5. (Otherwise they are as the relevant ETAG.)
4
CFA Guidance Note: Anchor terminology and notation
2
CFA
“How to” supply anchors in accordance with BS 8539.
(Issue 2. December 2013)
2 of 2