Solid Fuel Appliance Installation Requirements

What This Requirement Covers

Approved Document J covers the installation of solid fuel appliances including wood-burning stoves, multi-fuel stoves, open fires, and biomass boilers. These appliances must be installed safely with appropriate flue systems, hearths, and air supply to prevent fire, carbon monoxide poisoning, and structural damage.

Key Requirements

Hearths

1. A constructional hearth must be provided beneath and around every solid fuel appliance
2. Minimum dimensions: Extending at least 150 mm beyond each side of the appliance and at least 300 mm in front (or 225 mm if the appliance is enclosed)
3. Minimum thickness: 125 mm of non-combustible material (typically concrete)
4. The hearth surface must be non-combustible for at least 840 mm x 840 mm beneath the appliance

Flues and Chimneys

1. Every solid fuel appliance must be connected to a suitable flue
2. New chimneys must be constructed to BS EN 1443 and lined with a flue liner compliant with BS EN 1856 or BS EN 1457
3. Minimum flue size: 125 mm diameter (for stoves up to 20 kW) or as specified by the appliance manufacturer
4. Minimum chimney height: 4.5 metres from the top of the appliance to the top of the chimney pot
5. The chimney must extend at least 600 mm above the ridge of the roof (if within 600 mm of the ridge) or above the line drawn at 2.3 degrees from the ridge

Distances to Combustible Materials

1. The appliance and flue must maintain minimum distances from combustible materials:

- Stove body to combustible wall: Distance specified by the manufacturer (typically 150-450 mm, depending on the appliance and any shielding) - Flue pipe to combustible material: At least three times the external diameter of the flue pipe (or as specified in the manufacturer's instructions) - Chimney to combustible material: At least 200 mm air gap between the outside of the chimney and any combustible material

Air Supply

1. Solid fuel appliances require a permanent air supply for combustion
2. Appliances up to 5 kW: Permanent ventilation of 550 mm² per kW above 5 kW is required (no vent needed for the first 5 kW if the room is not sealed)
3. Appliances in airtight buildings (below 5 m³/(h.m²)): A direct external air supply to the appliance is recommended
4. The air supply must not be closable

Carbon Monoxide Alarms

1. A carbon monoxide alarm must be installed in any room containing a solid fuel appliance
2. The alarm must be positioned on the ceiling or at head height on a wall

HETAS Registration

1. Solid fuel appliance installation should be carried out by a HETAS registered installer (competent person scheme)
2. HETAS registration allows the installer to self-certify compliance with Building Regulations, avoiding the need for a separate Building Control application

Practical Compliance Tips

1. Always check the appliance manufacturer's installation instructions for specific clearance distances, flue requirements, and air supply
2. Ensure the flue is swept and inspected before connecting a new appliance to an existing chimney
3. Use a carbon monoxide alarm even if not strictly required; it is a cheap, life-saving precaution
4. Do not install a stove in a room with an MVHR system without consulting the MVHR manufacturer; negative pressure can draw fumes into the room
5. Check the smoke control area status of the property's location; in smoke control areas, only DEFRA-exempt appliances can be used
6. Keep the HETAS certificate and appliance documentation for Building Control and for the property records
7. Consider the impact of the flue terminal on the external appearance, particularly in conservation areas