A cladding
system designed to accommodate differential movements between an aluminium frame
and metal-faced insulation-cored cladding panels experienced gradual
displacement of building components as the gaskets snaked their way along the
grooves between shuffling panels.
The panels,
being small, elongated less on heating than the relatively long frame
sections. The connection between the two
was a combination of shelf brackets and clamps, with polymer gaskets inserted
tightly into grooves between the panels to complete the weather-sealing. Long continuous gaskets ran horizontally;
vertical gaskets were shorter
When the
system heated up and expanded, the panels and vertical gaskets tended to move
upwards. When it cooled, the panels and
gaskets contracted but did not uniformly return to their original
positions. The consequence was a gradual
displacement of parts of the system relative to one another. This opened gaps at the butt joints between
horizontal and vertical gaskets and, in places, drove the vertical gaskets into
the horizontal gaskets, deforming them.
Those panels on the elevations which received most sunshine moved
progressively out of alignment.
The design
was intended, by avoidance of rigid fixings, to allow reciprocal movements
without distress. But this lack of
rigidity allowed each reciprocal movement to cause slight relative displacements
in the panels and gaskets, the accumulation of which over time reduced weather
resistance and marred appearance. |
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