Distance To Combustible Material [DTC]

Distance to combustible material refers to the minimum safe space that must be maintained between a stove (or its flue) and any materials that can catch fire, such as wood, plasterboard, wallpaper, carpet, curtains, or furniture.

Importance of Distance to Combustibles

This distance is crucial for fire safety and to comply with Building Regulations. Stoves get extremely hot during use, and placing them too close to flammable surfaces or objects can create a serious fire risk. The required distance varies depending on:

• The type and model of stove
• Whether the stove has built-in heat shields
• The type of combustible material nearby
• The installation environment (e.g. freestanding, inset, in a recess)

Manufacturers specify these distances in their installation manuals, and they must be followed carefully. If needed, non-combustible shielding (like fireboard or heat shields) can be used to safely reduce the required distance.

General Guidelines

Each stove model will have its own manufacturer-specified clearance distances, but as a general guide:

• To the rear and sides of the stove, the distance to any combustible surface typically ranges from 300mm to 600mm, depending on the stove's design and whether heat shields are used.
• If the stove is placed in a recess or fireplace opening, it must have sufficient clearance on all sides to prevent overheating of surrounding materials and allow proper airflow.
• Twin-wall flue systems also require clearance—typically 50mm to 70mm—from combustibles along their entire length, unless otherwise stated by the manufacturer.
• Above stove to Wood Beams / TV etc – minimum 450mm

Some stoves are designed with integrated heat shields, allowing them to be installed closer to combustible materials.

Always consult the stove’s installation manual and Approved Document J of the UK Building Regulations for full compliance.

Failing to follow the correct distances can lead to fire hazards, invalidate warranties, and breach building codes. A qualified installer should always handle the installation to ensure safety and certification.

Heat Shields

Heat shields are protective barriers made from non-combustible materials that are installed behind, beside, or underneath a stove to reduce the amount of heat transferred to nearby surfaces. Their main purpose is to allow stoves to be installed closer to combustible materials without creating a fire hazard.

Key Functions of Heat Shields:

• Reduce clearance requirements between the stove and walls or furniture
• Protect surrounding surfaces from excessive heat exposure
• Help maintain safe operating conditions in confined or recess installations
• Improve air circulation and reflect heat back into the room

Types of Heat Shields:

• Integrated Heat Shields: Some stoves come with built-in rear or side heat shields, reducing the required distance to combustibles—often by half.
• Wall-Mounted Heat Shields: Installed directly on walls behind or beside the stove, these usually have an air gap behind them to disperse heat effectively.
• Floor Heat Shields: Made from non-combustible materials like metal or stone, these are placed underneath the stove to protect floors that are not naturally heat-resistant.

Heat Shield Considerations & Materials

When considering any bespoke heat shielding for a stove in a free-standing installation (one that's not situated within a fireplace recess) you must refer to BS8303 which outlines the protection needed to be given to combustible materials in order to comply with Building Regulations Document J, Section 4.

Heat shielding should be manufactured from suitable non-combustible materials, for example 1.5mm minimum thick steel, appropriately fixed using non-combustible fixings.

Key points for bespoke heat shielding:

• A 25mm air gap should be maintained between the rear surface of the heat shield and the face of the protected combustible material.
• Heat shielding panels should be open at the top and bottom to provide a flow of air through the gap between the heat shield and the protected area to prevent heat building up.
• Minimum distance of the heat shield to the closest point of the stove should be 95mm (unless the stove manufacturer stipulates less for their stove when it is fitted with their rear heat shield).
• Minimum distance of single skin vitreous enamelled single skin flue pipe to the heat shield should be 1.5 times its diameter: 188mm each side for 125mm (5") and 225mm for 150mm (6"). In order to reduce this you could leave out the single skin connecting pipe and use twin wall (with the appropriate adaptor) straight off the top of the stove.
• Minimum distance from the top of the stove or single skin flue pipe to the top edge of the heat shield should be 300mm.
• The overall width of the heat shield should be at least the width of the hearth which should conform to building regulations. The minimum width for a free-standing hearth is 840mm and in the case of wide body stoves the hearth should also provide a minimum distance of 150mm from the sides of the stove.

Materials: Steel or aluminium / Vitreous enamel-coated metal / Fire-rated board (like vermiculite or cement board) / Stone or slate

In Summary:

Heat shields are essential if you’re installing a stove near combustible materials or within a tight space. They enhance safety, meet regulatory requirements, and offer peace of mind—especially when installed correctly by a qualified professional.