October 2018

Technical Tips
BATTENS: “THEY’RE CRUCIAL TO THE
OVERALL SECURITY OF THE ROOF”
Marley Eternit, manufacturer of the JB-Red batten, provides roofers with some top tips for
batten installation.
When you think of a secure pitched roof, battens aren’t always the first thing that comes to mind because they are hidden by the roof covering.
However, they are actually crucial to the overall security of the roof, providing a reliable anchor that tiles or slates can be securely fixed to. Battens
also play a part in ensuring the rigidity, durability and weather tightness of the finished roof. That’s why, whether you’re working on a new build or a
refurbishment project, all battens need to be installed in accordance with BS 5534: 2014.
Below are Marley Eternit’s top tips on storing, setting out and fixing battens to make sure your roof is compliant with the Standard:
Preparation and storage
1: Only ever use a roofing batten that is marked
BS 5534 compliant – make sure you check the
stamp on the batten yourself.
2: Store battens and counter battens on
sufficient bearers to prevent sagging or twisting.
Protect them from water saturation when stored
in bales or bundles horizontally.
Batten length, size and spacing
3: Before installing the battens, check you have
the size and spacing right as this can have a
direct influence on the weather tightness of the
roof, as well as the finished appearance.
4: The appropriate batten size will depend on the
span of the rafters and type of roof covering you
are using. BS 5534 includes a table of
recommended minimum batten sizes (see below).
For example, 25 x 50mm battens should be used
for single-lap interlocking tiles when laid on
rafters with a 600mm span.
5: Battens should be fixed to rafters set at
centres not more than 600mm apart. They should
span at least three rafters and be at least 1.2m
long.
6: No more than one in four
battens should be joined over
one truss for gauges over
200mm. For gauges less
than 200mm, there can
be a maximum of three
consecutive joints in any
twelve battens.
Using a spread of batten lengths
is a good way to achieve the above
two requirements, as it results in staggered
joints.
Fixing
7: When you’re ready to secure the battens to
the rafters, ensure you’re using the right nails.
BS 5534 states that the nails used to fix battens
to rafters should usually have a diameter of at
least 3.35mm. The nails should provide a
minimum of 40mm penetration into the rafter, so
a nail length of 65mm is generally
recommended.
8: Start at the lower edge of the roof, nailing the
batten into place at the centre of the rafter. Joints
should be directly over rafters, with the batten
square cut, tightly butted and skewed nails.
9: If a batten end is to be set in mortar, make
sure an appropriate preservative treatment has
been applied. This is not required when using a
dry fix system.
Wall fixing
10: When fixing to a wall, fix
specified battens to
boarding / sheathing
sarking in line with
vertical supports, or to
masonry wall as specified.
Secure counter battens to
masonry walls with improved
nails or with plugs and screws.
Other battens considerations
11: When fixing dry verges to battens, under the
new BS 8612 Standard they can no longer be
installed with just a nail fixing into the end grain
of the batten. Instead, mechanical engagement
must be achieved when fixing a dry verge to the
batten. Using a system with a batten end clip can
make this easier.
12: Counter battens: if you’re using a vapour
permeable (breathable) membrane with a close
fitting roof covering – such as shingles – then it
needs to be counter battened to allow ventilation
of the batten space. The position of the first
batten should be the batten gauge plus half the
thickness of the batten. The batten gauge
thereafter is based on the pitch of the roof.
Contact Marley Eternit
01283 722 588
www.marleyeternit.co.uk
@MarleyEternit
38 TC OCTOBER 2018