Pitched roofs

Also see:

7.2.16Firestopping and cavity barriers

Pitched roofs shall be constructed to provide adequate fire resistance and separation.

Firestopping should be provided in accordance with building regulations, including:

  • at the junctions between a separating or compartment wall and a roof
  • at the junctions between cavities
  • above separating walls
  • within the boxed eaves at separating walls.

When providing firestopping:

  • gaps between compartments should be sealed
  • separating walls should stop approximately 25mm below the top of adjacent roof trusses, and a soft fire-resistant packing, such as mineral wool, should be used to allow for movement in roof timbers and prevent ‘hogging’ of the tiles
  • a cavity barrier of fire-resisting board or a wire reinforced mineral wool blanket (50mm minimum) nailed to the rafter and carefully cut to fully seal the boxed eaves should be installed (ordinary mineral wool quilt is acceptable as firestopping above separating walls)
  • a minimum 30min fire separation should be provided between the home and an integral garage.

Combustible material, such as roof timbers and sarking felt, should be kept away from heat sources.