HETAS has issued updated information on fixings for stone fire surrounds. Here, technical standards manager Calvin May gives a brief outline of the essentials.
(First published in RGE’s August 2018 issue)
Fire surrounds have been the subject of recent media attention following a number of incidents where an inert stone surround came away from the wall, posing significant risk to the building’s occupants and, in some cases, serious injury and fatality.
Hetas’s recent Technical Bulletin offers advice on essential practices when fixing a stone fire surround to either an open fire or closed appliance builder’s recess.
In 2015, the technical committee responsible for the management of the open fire components standard BS 1251 revised and updated the 1987 version of the standard to include new requirements for the appropriate method for mechanically fixing a fireplace surround. This was aimed at ensuring that it can take the load of objects placed on the mantle above and won’t come away from the wall if they are pulled on accidentally.
Materials and structures of a fire surround
To understand the basic principles of fixing a fireplace surround, it is as important to understand the type of surround being fitted as it is to ensure the correct positioning, materials and fixings are used for installation.
The different types of surrounds available can be summarised as:
- Slabbed surrounds – a single-component structure, usually made from marble, stone or ceramic tiles, on a backing of heat-insulated cement mix. The minimum total thickness of the surround shall be no less than 48mm, consisting of at least 30mm of cement-mixed backing for stone and marble, and at least 40mm mix for ceramic tile
- Cut stone surrounds – a multiple-component structure, typically constructed of stone formed of two vertical legs under a horizontal lintel, with mantle on top
- Boxed section surrounds – a multiple-component structure, made from natural stone or marble, compartmentalised with a back panel split to allow for thermal expansion.
All surround types as described above should be manufactured in accordance with BS 1251, and in such a way that allows for the appropriate mechanical fixing of the surround to the building’s structure. If you are unsure whether the surround conforms, contact the manufacturer directly and request clarification on the correct procedure to follow. You can also seek further specialist advice and guidance from specialist organisations such as Hetas or the Stone Federation of Great Britain.
Fixings must be secured to the brickwork of the building, so it is important that any plasterboard or other finish materials are removed beforehand to allow for the surround to be bonded appropriately. Installers should never use the ‘dot dab’ adhesive method to affix a surround to the building’s internal structure.
For slabbed surrounds, typically the manufacturer will integrate the appropriate clip or eyelet type fixing to the product directly, with two mechanical fixings positioned at each side of the surround, and a further two fixings within 300mm of the top. These will be usually either a fixed or swivel type, depending on the surround’s construction.
Cut stone surroundsare a little more complex and should incorporate full heat-proof bracket fixings appropriate for the type and construction of the backing wall. It should be fixed directly to the chimney breast wall or fixed to another stone structure, which itself is mechanically fixed to the breast wall. The manufacturer’s instructions will provide additional fixing instructions on the location, type and bedding joints needed to fix the surround correctly.
Boxed section surrounds incorporate fixing wires at each side of the surround, similar to slabbed surrounds, with the uppermost fixings within 300mm of the top of each side. The shelf at the top will have its own fixing points to secure it to the chimney breast wall. The manufacturer’s instructions should be followed at all times as installation may be dependent on the size and weight of the shelf overhang.
In most cases fixing brackets will be supplied by the surround manufacturer. These are typically made of heat-proof stainless or galvanised steel in such a way that enables them to be fixed into the surround. It is important to assess the condition of the chimney breast wall to ensure it can accommodate the weight of the surround.
- Ensure the surround complies with BS 1251 requirements
- Before installation, ensure the manufacturer’s instructions are referenced and give provision for the appropriate fixing type, locations, correct methodology and any required jointing/sealing compounds
- Assess the wall and hearth structures and ensure they are in a condition to accommodate the weight of any surround
- Upon completion, assess any potential risk to the occupants and inform them of potential dangers where children or infirm people are present.
More information on the correct fixings for stone fire surrounds is online at
Hetas is a not-for-profit organization offering a Competent Person Scheme for installers of biomass and solid fuel heating, registration for retailers, servicing technicians and chimney sweeps, and approval of appliances and fuels.
PDF copies of the full Hetas guidance on fixing stone fire surrounds, as published in RGE’s August 2018 issue, can be downloaded here.