4.2.1 A "primary deck covering" is the first layer
of a floor construction which is applied directly on top of the deck
plating and is inclusive of any primary coat, anti-corrosive compound
or adhesive which is necessary to provide protection or adhesion to
the deck plating. Other layers in the floor construction above the
deck plating are "floor coverings".
4.2.2. When the product that is the first layer
of a floor construction which is applied directly on top of the deck
plating and is also the exposed surface (i.e. no other layer applied
on it), it shall be considered as the "floor covering", and shall
comply with the requirements of "floor covering".
4.2.3 Where a floor covering is required to be
low flame-spread, all layers shall comply with this part. If the floor
covering has a multilayer construction, the Administration may require
the tests to be conducted for each layer or for combinations of some
layers of the floor coverings. Each layer separately, or a combination
of layers (i.e. the test and approval are applicable only to this
combination), of the floor covering shall comply with this part.
4.2.4 Primer or similar thin film of paint on
deck plating need not comply with the above requirements.