The ceiling should be positioned below a structural core
constructed in accordance with 2.2.1.
The design of the ceiling should be such that it facilitates its assembly
with the limited access provided by the proximity of the structural
core, i.e. it should be mounted with the structural core in place.
During a test on an "A" class deck which utilizes membrane
protection along its underside, e.g. a "B" class ceiling, it is possible
also to evaluate the performance of the ceiling with a view to classification
providing that the necessary thermocouples are attached to the ceiling
and providing that the necessary integrity measurements are made.
If the ceiling incorporates panels, the specimen should
include examples of both the lateral and longitudinal joints between
the panels. If the specimen is to simulate a ceiling where the maximum
length of the panels is greater than the length of the specimen, then
a joint should be positioned at a distance of approximately 600 mm
from one of the shorter ends of the test specimen.
The specimen should be constructed such that at least one
of the panels is of full width and this, or these, should be positioned
such that both its/their longitudinal edges are jointed to an adjacent
panel and are not secured to the restraint frame.
If the ceiling may incorporate electrical fittings, e.g.
light fittings and/or ventilation units, it is necessary that initially
a test is performed on a specimen of the ceiling itself, without the
incorporation of these units, to establish the basic performance.
A separate test(s) may be performed on a specimen(s) with the units
incorporated to ascertain their influence on the performance of the
ceiling.