Fireplaces, chimneys and flues

6.8.8Gas – fireplaces and hearths

Fireplaces and hearths shall safely accommodate the fire or appliance for which they are designed. Issues to be taken into account include:

  1. separation from combustible materials
  2. provision of hearths and recesses.

Gas appliances should be:

  • fitted by a Gas Safe Register (GSR) installer, and
  • comply with the Gas Safety (Installation and Use) Regulations 1998.

Separation from combustible materials

Appliances should not be closer than 75mm to combustible material. This applies to:

  • the back, sides and top of the appliance
  • draught-diverters.

It does not apply:

  • where a 25mm thick non-combustible shield is used, or
  • to gas-fired appliances with CE marking, installed in accordance with the manufacturer’s written instructions, which clearly indicate such separation is not necessary.

Provision of hearths and recesses

Solid fuel effect appliances

Hearths and recesses for solid fuel effect appliances should be:

  • in accordance BS 5871
  • in accordance with the requirements for solid fuel appliances (see Clause 6.8.3), or
  • where the appliance has been tested by an approved authority, in accordance with the manufacturer’s instructions.

Back boilers

Hearths for back boilers should be constructed of solid non-combustible materials, a minimum of:

  • 125mm thick, or
  • 25mm thick and placed on non-combustible supports which are a minimum of 25mm high.

Other gas appliances

Hearths for other types of appliance should be constructed of non-combustible materials which:

  • are a minimum of 12mm thick
  • comply with the plan dimensions for back boilers.

In some cases, the provision of a hearth is not required, e.g. where the flame or incandescent material is at least 225mm above the floor.

For all forms of gas appliances the hearths should be marked at the edges to:

  • provide a warning to the home owner
  • discourage combustible floor finishes, such as carpet, from being laid too close to the appliance (this can be achieved by introducing a change in level).