Technical Booklet E Fire Safety·Page 86·3.10(c)(d)
Definition of ceiling surface for fire classification
Specifies what components are included and excluded from ceiling surface calculations for fire safety, including sloped walls and various openings.
a ceiling should include –
(i) the surface of glazing; and
(ii) any part of a wall which slopes at an angle of 70º or less to the horizontal; and
a ceiling should not include –
(i) trap doors and their frames;
(ii) the frames of windows or rooflights and frames in which glazing is fitted; and
(iii) architraves, cover moulds, picture rails, exposed beams and similar narrow members.
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