Last edited 31 Jul 2015

Definition of ceiling

Approved document B, Fire Safety, Volume 1 Dwelling houses, defines a ceiling as:

A part of a building which encloses and is exposed overhead in a room, protected shaft or circulation space. (The soffit of a rooflight is included as part of the surface of the ceiling, but not the frame. An upstand below a rooflight would be considered as a wall.)

For the purposes of the performance of ceiling linings, a ceiling includes:

  • the surface of glazing;
  • any part of a wall which slopes at an angle of 70º or less to the horizontal;
  • the underside of a gallery; and
  • the underside of a roof exposed to the room below.

But a ceiling does not include:

  • trap doors and their frames;
  • the frames of windows or rooflights and frames in which glazing is fitted; or
  • architraves, cover moulds, picture rails, exposed beams and similar narrow members.