A wood-burning stove with an environmentally friendly heating system can significantly enhance your home. However, properly installing your stove is crucial for safety. One key consideration is fitting a register or closure plate in the chimney. This guide will explain what these plates are for and when each type is required. 

What is a register plate?

A register plate is a metal plate fitted at the base of a chimney, just above an installed wood-burning stove. Its purpose is to seal off the chimney space and prevent smoke, fumes, and other combustion gases from entering the room from the lit stove below. 

Register plates are typically made from galvanised or stainless steel, with a minimum thickness of 2mm. This sturdy metal construction is specified because register plates play an important safety role. They must be strong enough to withstand impacts inside the chimney space without falling. For example, if a brick or other debris fell inside the chimney, a flimsy plate could be damaged, allowing dangerous fumes to leak into the living spaces. 

The register plate completely seals the chimney space at its base. Some designs incorporate hinged access doors so that chimney sweeps can open these up and reach into the space above the plate, for example, to clear out built-up soot. The image below shows a register plate with access hatches:

When is a register plate required?

Building regulations in the UK require a register plate to be fitted when installing a wood-burning stove if the chimney does not have a liner. A liner is a rigid metal tube that runs inside the chimney to directly connect the stove to the outside air. Most modern stove installations include a liner. 

Product Guide: Does My Chimney Need a Liner?

Without a liner, the stove flue pipe connects straight to the chimney space itself. This means that the register plate is essential for safety, as it contains the smoke, fumes, and gasses from the lit stove and prevents them from backing up into the room. 

Some examples of when you might need to use a register plate because no liner is present include:

• Older properties with pot-lined chimneys 
• Installing a stove in a large, open fireplace recess without a liner
• Connecting the stove to a chimney shared with another appliance 

In cases like these, building regulations would require fitting a proper metal register plate to seal off the chimney space. Alternatively, it is recommended to install a suitable chimney liner when adding a new wood-burning stove if one is not already present. 

What is a closure plate?

A closure plate serves a similar purpose to a register plate, sealing off the chimney space from the room below. However, a closure plate can be used when a chimney liner is present. 

With a liner installed, the smoke, gases, and fumes from the stove are contained inside the rigid metal liner tube. They do not mix into the chimney space around the liner. Therefore, the closure plate must neatly close off the chimney opening. It does not have to be engineered to the same exacting safety standards as a register plate. 

Closure plates are typically made from non-combustible materials like concrete, vermiculite, or calcium silicate board. These are easier to work with and cut than metal. Access hatches for sweeping are not required, as the liner channels all the combustion products safely up and out of the chimney. 

The main purposes of a closure plate are:

• Stopping warm air from the chimney being drawn into the room, reducing heat loss. 
• Preventing loose debris and old soot deposits in the chimney from dropping down onto the stove. 
• Giving a neat, tidy visual finish to the chimney breast installation. 

Closure plate vs register plate

The key difference between register plates and closure plates is that register plates play an important safety role as part of the flue system. Closure plates simply provide a cosmetic seal after a liner has been fitted. 

Some additional points to consider:

• Building regulations only require register plates for unlined chimney installations. Closure plates are optional, though highly recommended. 
• Some installers opt to include an access hatch in closure plates for inspection purposes if space allows. 
• A register plate must be meticulously fitted with heat in closure plates for inspection purposes, if space allows. 
• A register plate must be meticulously fitted with heatproof sealant, as any gaps could allow deadly fumes to leak into the room. Closure plates are under less pressure to be 100% airtight. 
• Repairing or replacing a damaged register plate requires great care, due to the safety risks. A damaged closure plate can be replaced more readily if needed. 

We recommend always using a specialist flue and chimney company to install your stove and provide advice on whether a register plate or closure plate is required. They can ensure your system is properly sealed and compliant with building regulations. 

Fitting a chimney liner

It is advisable to install a chimney liner when fitting a new wood-burning stove where possible. This avoids the need for a register plate, allowing a simpler closure plate to be used instead. 

DIY Guides: How to Fit a Chimney Liner

Liner options include:

• Stainless steel flexible liners
• Rigid stainless-steel liners 
• Ceramic/clay liners

A liner ensures all combustion gases are safely directed outside via the chimney. Without one, a register plate provides the vital barrier between the stove and living space. However, access for cleaning can be more difficult. 

Your chimney may already have an older liner installed that can potentially be used. If not, a new liner will need retrofitting. A professional chimney sweep can survey your chimney and advise on the best liner for your stove installation. 

Hopefully, this guide has helped explain the crucial differences between register plates and closure plates when installing your wood-burning stove. Correctly identifying if you need a register plate and fitting it correctly is vital for safety. Alternatively, investing in a chimney liner allows a more straightforward closure plate to be used.