September 2019

Graded Battens
6 STEPS TO BATTEN SUCCESS
Jenni Forrest, Quality Manager for JB Red at Marley, answers contractor queries about
roofing battens.
Roofing battens are one of the most important parts of a pitched roof structure, acting as a
structural and load-bearing element. As well as supporting the dead weight of tiles and the
imposed wind loads, BS 5534 graded roofing battens can also be used as a secure foothold
during installation. That’s why checking the quality and compliance of the roofing battens you are using
is so important.
Below we answer some common contractor queries about
choosing and installing roofing battens:
JB Red battens being loaded into the treatment vessel.
1What batten defects are allowed under
BS 5534? As a natural material, timber
battens will obviously have varied
characteristics but BS 5534 is very strict about
what is and isn’t allowed, and our machine
grading process scans battens by the millimetre
to make sure they meet the requirements of the
standard.
Some knots are allowed, depending on their size
and position. If a knot appears on both sides of
the face, the sum of the knot on both faces must
not exceed the width of the batten. A knot
appearing on both sides of the batten which does
not appear on the face is only deemed
permissible if the knot on either side is one-fifth
of the depth or less.
BS 5534 also allows for a missing corner on the
batten, otherwise known as wane. However, it is
only permitted on one axis and should not exceed
one-third of the dimension of each of the faces
on which it occurs.
For a full list of permissible defects, we have put
together a free pocket checklist to help
contractors ensure they are using quality,
compliant battens. For your free copy, email
info@marley.co.uk.
If you have any doubts about a possible defect,
check with the manufacturer before you use the
batten.
2Do battens have to be completely
straight? Battens need to be straight, so
BS 5534 sets a tolerance on distortion.
Bow, spring or twist should each not be greater
than 5mm, measured over a length of 1.2m at a
reference moisture content of 20%. If your batten
is bowed more than this, then do not use it and
check with the manufacturer.
Battens cut from sideboards are less likely to
distort which is why JB Red battens are only
manufactured from kiln dried sideboards.
3Aren’t all graded battens the same? If
you have two battens from different
manufacturers, both graded to BS 5534,
many people would assume that they are the
same. However, this may not be the case and just
like other roofing products, there can be
significant variations in quality and performance.
Indeed, it is surprising how many differences
there can be between similar looking roofing
battens – from the way they are graded, through
to the type of timber they are made from, the
quality processes they go through and the
preservatives they are treated with.
To make sure roofing contractors know how to
choose the best quality battens, at Marley we are
carrying out an education campaign to ensure our
customers know how to spot the differences
between graded battens. This includes the launch
of our new batten CPD which our sales teams will
be delivering to contractors across the country, as
well as the free pocket checklist.
4I’ve been told that all coloured battens
are BS 5534 compliant, is that true? No.
The issue of batten colour has caused
some confusion. Whilst the distinctive red colour
of our JB Red battens along with other coloured
battens from reputable manufacturers does give
peace of mind that you are using a BS 5534
compliant batten, this is not necessarily the case
for all battens. Please don’t assume that just
because it is coloured that a batten meets the
required British Standard. It must also have the
correct stamps and supporting documentation.
5Do counter-battens need to be graded
to BS 5534? There has been some
confusion about whether-counter battens
also need to be graded to BS 5534. Counterbattens
do not need grading, providing they are
fully supported and are fit for their intended
purpose. The dimensions of counter-battens
should be sufficient to provide a ventilation gap
for close fitting roof coverings as recommended in
BS 5250 and/or to provide a drainage path
beneath the battens.
For more help with choosing and grading roofing
battens, request your free battens CPD training
session or pocket checklist by emailing,
info@marley.co.uk.
Contact Marley
01283 722588
www.marley.co.uk
@MarleyLtd
32 TC SEPTEMBER 2019