Fireplaces, chimneys and flues

6.8.22All – flues

Flues shall be suitable for their purpose and adequately separated from combustible materials.

Flues should be:

  • suitable for the type and size of appliance which they serve
  • constructed in accordance with the design and the manufacturer’s recommendations
  • tested in accordance with this chapter.

Combustible materials close to any brickwork or blockwork chimney should be:

  • 200mm minimum from a flue
  • 40mm from the face of the chimney, in Scotland, and
  • metal fixings in contact with combustible materials should be a minimum of 50mm from the flue.

This does not apply to a floorboard, skirting, dado or picture rail, mantel shelf or architrave.

Twin wall flue systems should comply with:

  • BS EN 1856, or
  • be assessed in accordance with Technical Requirement R3.