8 | DECEMBER 2018
News
Read online at www.proinstaller.co.uk
TOP TIPS:
INSTALLING
SECURITY
GLASS
Phil Brown, European regulatory marketing manager
at Pilkington United Kingdom Limited, part of the NSG
Group, offers his top tips to help installers understand
the key regulations when installing security glass.
Security glass means de-
signers don’t have to compromise
between protecting buildings and
allowing them to be filled with
natural light.
It is used in applications where
either people or property needs
to be protected, whether against
manual attack, firearms or explo-
sions.
Here are our top tips for in-
stallers working with this product
type:
1. Every element matters
The security glazing products on
the market today can provide an
impressive level of resistance to
attacks, whether these are carried
out using hands and feet, a tool
such as a brick or an axe, or even
ballistics or explosives.
However, no matter how ef-
fective the glazing might be in
standing up to these attacks, its ef-
fectiveness will be undermined if
the framing and supports keeping
it in place do not provide at least
the same amount of resistance.
So, any method used to fix se-
curity glazing in place must have
enough strength to stand up to the
anticipated means of attack. This
includes any doors or other means
of access in which the glass might
be installed. If suitably configured,
the glass is designed to break but
stay in place.
2. Lock in the edges
A 50mm-thick sheet of lami-
nated glass that might be able
to stand up to an attack with an
axe won’t protect a building if an
attacker is able to lever it out of
its frame, so ensuring rebates are
deep enough to prevent this is
essential.
One of the major benefits of
appropriately designed laminated
glass is that the interlayers retain
their integrity even if the glass
is fractured, so any would-be
intruder won’t be able to enter the
building even if they attack the
glass hard enough to break it.
Again, though, this benefit only
holds true if all edges of the glaz-
ing are properly ‘locked’ in place
inside the rebates. This can either
be done by clamping pressure –
usually only in the case of single
glazing – or, more likely, by using
an appropriate sealant.
Where the lower edge of the
glass meets a counter top – as is
the case in many applications from
banks to convenience stores – the
structure connecting the two ele-
ments must provide the same level
of support as for the other edges
of the glass. This includes areas
around any apertures intended for
transactions or communication.
3. Consider whether
the glass is designed
to fracture
When laminated security glazing
is specified, there are two differ-
ent approaches to providing the
required level of resistance – glass
that is designed to break in the
event of an impact, while remain-
ing in one piece, or glass that is
strong enough to resist fractur-
ing.
Sometimes a specifier will
choose glass intended to crack
because it offers a more affordable
solution while still delivering a
high level of access prevention.
Which approach the specifier
has taken has an important impact
on the framing that must be used
to hold the glass in place. This is
because a pane that is intended to
break will exert less force on its
framing than one that is designed
to maintain its structural integri-
ty.
For glass that is not intended
to break, the fixing design will
be significantly more heavy duty,
especially if the glass is intended
to provide resistance to explosive
blasts. In such cases, the forces
that will be transferred from the
glass to the framing and the whole
building structure must be consid-
ered by the building’s designer.
Where the glass is intended to
fracture, the key is to use rebates
that are deep enough to keep a
broken pane of glass, held togeth-
er by its interlayer(s), in place.
Ideally, a tested framing system
and proven fixing method should
be used. In general, increased
edge cover may be necessary com-
pared with conventional glazing
systems.
4. Get the right support
To ensure the installation will
stand up to the specified level of at-
tack, it is important that it is strong-
ly anchored into the building.
Any vertical supports, or mul-
lions, must be securely fixed at
ceiling and floor levels, and gener-
ally they should be taken through
any suspended ceilings and raised
floors and fixed to structural ele-
ments of the building.
In the same way, horizontal
supports, or transoms, should be
securely fixed at each junction
with the vertical supports and
walls where appropriate.
5. Know your standards
Specifications for the security
glass that should be used in any
given application are laid out in a
series of British Standard docu-
ments.
It’s worth referring to the
relevant standard(s) whenever
you set out on a security glazing
installation, to ensure all elements
comply and to instil confidence in
your clients.
For example, in the case of
resistance to manual attack the
relevant standard for the glass is
BS EN 356, for which classifica-
tions range from P1A (the lowest)
to P8B (the highest). There are
equivalent standards for windows
and doors, for example BS EN
1627 for burglar resistance. Other
standards are available covering
ballistics and blast resistance.
The standards are available on
the BSI website, www.bsigroup.
com.
www.pilkington.co.uk