The ABCB released a video earlier this year that answered the question, ‘Is the internal lining of an external wall a part of that wall?’

The video clarifies that, yes, the lining is a part of the wall and so must be non-combustible in Type A and Type B buildings.

Further questions have been asked about minor attachments to the internal lining of an external wall; specifically whether these also need to be non-combustible in Type A and Type B buildings.

Here is some initial guidance however further information is also available from the Advisory Note: Fire performance of external walls and cladding.

Internal lining of an external wall required to be non-combustible

An internal lining of an external wall is a wall element that lines and covers the wall. Plasterboard is a typical example of an internal lining. In a Deemed-to-Satisfy Solution, where an external wall is required to be non-combustible, the internal lining must be non-combustible unless granted a concession by C1.9.

There are minor building and decorative elements often fixed or attached to an internal lining, such as:

  • skirting boards
  • cornices
  • architraves
  • power points, and
  • switches.

These elements do not function as the internal lining, nor are they integral parts of the internal lining or the wall. As such, by virtue of not being a part of the wall, they are not subject to the requirements of C1.9(a)(i) to be non-combustible when installed as part of the internal lining to an external wall.

C1.10 Fire hazard properties

It is also important to consider the requirements of C1.10, alongside C1.9(a)(i), because both provisions apply concurrently to the internal lining of an external wall. For example, plasterboard is permitted where non-combustible materials are required (C1.9(e) provides concession), but is also subject to the requirements of C1.10(a).

Further, C1.10 applies to some attachments to the internal side of an external wall, even where they are not a part of the wall.

More information

The video released earlier this year is available from the Resource Library.