Shane Jerram, operations director at Able Canopies discusses the importance of site specific calculations to
ensure each canopy meets all the relevant performance and safety standards.
A strong foundation
A canopy’s foundations are vital to its structural
stability as mentioned above with the member
sizes. All canopy foundations should be
individually assessed to make sure they provide
adequate anchoring – for example, a canopy in a
higher, more exposed location would require larger
foundations to cope with the increased wind loads
that such an environment would create.
The perfect fix
Once the size of the installation has been agreed
and the foundations checked, the correct fixing
bracket will be required to ensure the canopy
can be fixed to an existing building in a way that
ensures a strong join. If access to strong structures
such as steel beams or solid brick work is not
possible, then a bespoke fixing will be designed.
This will need to have its own set of calculations
to ensure it can take the loads that will be placed
on it, and that it will safely and securely keep the
canopy in place.
Whatever the weather
A lot of the calculations completed externally will
be relating to the weather – after all, the canopy is
upgrading an outdoor space that requires shelter
from the elements. In the UK, there is an average of
133 days of rain and snowfall per year, so this will
need to be considered to ensure the canopy is able
Showing what they’re made of
The material used will of course come into
consideration. Timber will have a different weight
to aluminium, for example, and will require
different maintenance and calculations to ensure it
is suitable for end use.
Many end-users are keen to take advantage of
unique elements that can be added to the canopies
– such as solar panels, so they can generate their
own energy. Understandably, these additions will
require different calculations, as it will change the
weight of the roof system.
When these complexities occur, the required
calculations will need to be produced to meet the
demands of the site and ensure safety for all users.
An example of this is the installation at
Bournemouth University by Able Canopies. The
two bus shelters brought together several the
variables mentioned above – the addition of solar
panels, unique finishes to the ends of the canopies,
an exposed position to the weather, and the use of
steel on a large scale.
The calculations for this installation alone ran
to over 90 pages, which shows the level of detail
required to ensure that a unique installation of this
type is safe and will be able to withstand extreme
conditions such as strong winds and large snowfalls.
Upgrading outdoor space into a usable,
sheltered area provides a host of benefits for all
kinds of applications. It is crucial that site-specific
calculations are carried out and thoroughly checked
to ensure the end installation is fit for purpose and
meets all safety requirements.
There are a range of canopy products
on the market to upgrade outdoor
spaces into usable, safe areas in all
weather conditions. The requirements
for each job can vary depending on the end-user
needs – and to ensure the most suitable solution
is installed, the specific site and potential weather
conditions should always be assessed. The footprint
and camber of the site and the materials of the
existing building will all have an influence on the
design and fixing of the canopy.
These factors will have an impact on the
structural integrity of the canopy and will always
be assessed at the survey stage. The canopy itself
is made up of several different extruded and
preformed profiles which are designed and tested to
ensure structural strength is maintained throughout
the life of the structure. The configuration and
setting out of these components is decided
only when a set of site-specific calculations are
undertaken, this is because different areas of the
country will be subject to higher/lower wind and
snow loadings, specific to the location.
Size does matter
Firstly, the height, span and projection of the
canopy will need to be considered to make sure
it suits the client's requirements. These will all
influence the proposed solution and ultimately the
canopy’s end usability. It is crucial to always ensure
that during the design stage to try to maintain
the largest useable footprint possible, i.e. by
minimising post positions, resulting in less posts
and more useable space.
BUILDING PRODUCTS | FEBRUARY