Fixing without a hitch
Though the majority of pitched roof tile installations go without a hitch, if there are issues, they are usually the
same ones. Mark Parsons, technical director at Russell Roof Tiles, discusses the most common mistakes that
can often be experienced when installing a roof
In the UK we continue to experience
an overwhelming change in
the climate, and with winds of
over 100mph being recorded
in localised areas of the country,
there is no room for substandard
roofing installation. Here at Russell
Roof Tiles, we know the importance
of fixing a roof correctly, as it plays a
critical role in protecting a building as its
first line of defence.
Getting the fixing spec right
The British Standards for Slating
and Tiling BS 5534 covers all aspects
of pitched roofing, and sets out tile
and accessories fixing and fitting
requirements to ensure that all UK
Building Regulations are followed.
BS 5534 is designed to make roofs
more secure in the face of increasingly
extreme weather events. Following the
last major 2014 revision of the code, every
single lap tile has to be mechanically
fixed, as mortar alone is no longer
deemed sufficient to secure tiles and
fittings to a roof.
Although it is not a legal
requirement, a roof specified to the
code of practice can be upheld by
law in both terms of the safety of
the roofer and the risk of damage to
Therefore, it is critical that
the roofing contractor obtains
a comprehensive written fixing
specification, which is site specific before
any work commences.
This can be obtained instantaneously
with specific fixing specifications on the
Russell Roof Tiles website.
Choosing the right product
Would you buy a car with a range of
different parts, some that were branded
and some that were not? Using different
parts designed and manufactured for a
completely different car?
This ‘mix and match’ approach to
products used, in terms of specifications
for tiles, accessories and fittings, is a
challenge the roofing industry faces today.
If we as members of the construction
industry seriously want to cut down on
defective roofs, it is not good practice to
Russell Roof Tile products, like many
other manufacturers, are designed and
tested for use in combination with each
other over many years.
It’s important to avoid leaks and other
issues by making sure interlocking tiles
are set out correctly, and therefore the
necessary broken bond is maintained.
Flat interlocking tiles must be installed
to a broken bond pattern, as it aids the
performance of the tiles and is also
more aesthetically pleasing. The broken
bond allows any water draining into the
interlock on one tile to disperse safely
onto a flat surface on the tile below.
If not laid broken bond, the effect
is that it weakens the overall roof
performance, and while it may not leak
initially, at some point under storm
conditions, it is then likely to fail.
Lead staining can be another issue, which
occurs when the lead develops a lead
carbonate patina, which when washed
over the tile by rain, causes unsightly
staining. When the installation of any
leadwork and flashings take place,
they must meet with the Lead Sheet
In order to prevent this reaction, it is
advisable to treat all lead with patination
oil (a protective coat applied to the lead
before and after it has been shaped) before
any rain occurs, and not later than the day
the lead is fixed.
Where specified, if the position of any roof
vents is known, they should be installed
at the same time as the roof tiles are
fixed. This is because installing as a retro
fit, or at a later date, would require the
removal on the finished roof tiles – which
may then cause unnecessary damage to
adjacent tiles and fixings.
“If we as
to cut down on
it is not good
practice to mix
60 www.rcimag.co.uk June 2020