Light steel framed walls and floors

6.10

6.10.5Control of fire

Walls and floors shall resist and control the spread of fire. Structural elements, fire stops and cavity barriers should have adequate resistance to fire and smoke. Issues to be taken into account include:

  1. walls, floors and ceilings
  2. cavity barriers and fire stops
  3. materials suitable for fire stopping.

Walls, floors and ceilings

Fire resistance should be in accordance with:

  • relevant building regulations
  • the design.

Ceilings should provide the necessary fire protection to floors constructed with light steel joists. This requires one or two layers of plasterboard, with at least one being fire-rated. Where two layers of board are used:

  • joints should be staggered between layers
  • they should be attached using self-drilling, self-tapping screws.

Cavity barriers and fire stops

Service penetrations in floors between homes should be fire stopped and there should be no holes or gaps for smoke to penetrate once the fire stopping has been installed.

Horizontal cavity barriers should be protected by:

  • a DPC tray with a 100mm minimum upstand
  • a polyethylene-encased cavity barrier with a 100mm minimum upstand, or
  • the eaves.

Materials suitable for fire stopping

Materials for fire stopping are acceptable where they are:

  • specified in supporting documents to building regulations
  • assessed in accordance with Technical Requirement R3.