Installation of rangehoods and splashbacks near cooktops

There are several rules regarding protection of surfaces, as well as clearance distances particularly around gas cooktops. 

There are also many different splashback materials used in houses today which have different requirements. Some of the more popular splashback materials and their construction requirements are detailed below.

Surface clearance

First and foremost, Australian Standard AS/NZS 5601.1 Gas installations (General Installations) notes that clearances between a gas cooking appliance and combustible surfaces must be in accordance with the appliance manufacturer’s specifications.

This is different to most Australian Standards referenced in the NCC which generally only contains informative references to manufacturers specifications. However, for gas installations it is important to follow these before consulting the Australian Standard AS/NZS 5601.

Where there are no installation instructions or specifications provided for an appliance, AS/NZS 5601.1 provides default clearance requirements.

The general intent of the provisions of AS/NZS 5601 is that gas appliances shall be installed such that the temperature of a nearby combustible surface does not exceed 65 degrees above ambient.

‘Combustible surface’ is defined and means: Any material or object made of, or surfaced with, materials that are capable of being ignited and burned’. This can include timber framing.

Protection of combustible surfaces

Where a combustible surface cannot achieve the required clearance, it must be protected. The Standard requires surface protection where the periphery or edge of the nearest gas burner is less than 200mm from the nearest vertical combustible surface.

Protection of a combustible surface can be achieved simply through the use of standard plasterboard or fibre cement sheet substrates of a minimum thickness.

The protection must be provided to a height of minimum 150mm above the periphery of the nearest burner for the full width or depth of the cooking surface area (the ‘cooking surface area’ does not include control knobs).

Do metal, glass or tile splashbacks provide protection for combustible surfaces?

Metal, glass and ceramic tiles may be non-combustible, but they are not sufficient to provide protection by themselves. 

These materials are conductive, so they can transfer heat to the substrate material or timber framing. This can have disastrous results.

The following table reproduced from AS/NZS 5601 provides acceptable methods for protection of combustible surfaces, including where metal, glass and ceramic tile facing is used.

What else is required for glass splashbacks adjacent to gas cooktops?

The installation of glass splashbacks is also covered in AS/NZS 5601 and it requires that glass used as a splashback adjacent to gas cooktops must be toughened safety glass a minimum 5mm thick and the glass must be marked ‘toughened safety glass’ to ensure that the glass is fit for purpose.

Alternative systems

If using ‘any other system’ as noted in the Table above, AS/NZS 5601 requires that the surface temperature of the nearby combustible surface will not exceed 65 degrees Celsius above ambient.

You would need to have a system tested or some other means of documentation to verify this.

Can a window be used as a splashback?

A popular design choice is using a window adjacent to a gas hotplate where often the glass will extend to bench height and will be within 200mm of a gas hotplate.

There are no specific provisions under the Standard for this situation but as a window isn’t protecting a combustible surface and the glass is a minimum 5mm thick toughened safety glass it should perform adequately. 

Ensure though that combustible parts of windows such as timber window reveals are protected if within 200mm and the Standard does note: Consideration must be given to window treatments and painted surfaces on glass splashbacks when located near cooking appliances.

Also, you should check if the appliance manufacturer places any restrictions around using a window as a splashback.

Kitchen rangehood requirements

AS/NZS 5601 provide minimum clearance requirements for kitchen rangehoods from gas hotplates and requires rangehoods to be installed as per manufacturer’s specifications but with a minimum clearance of 600mm.

What about electric hotplates?

The Australian Standard for electrical installations is AS/NZS 3000 (wiring rules standard).

There are no specific requirements for the installation of electric hotplates in AS/NZS 3000 but it is noted generally that electrical equipment, including appliances should be installed to ensure there is no danger of fire or high temperature.

Most importantly though it notes that electrical equipment and appliances shall be installed as per manufacturer’s specifications so this should be the first consideration, 
It is worth noting that any socket outlets or switches should not be installed adjacent to a gas or electric cooking surface in the area noted under the standard.

It would be best to contact your licensed electrical contractor to clarify this. 

Where can I find more information?

Your State or Territory Energy Regulator may have information on gas appliance installation, which is generally information taken from AS/NZS 5601.

Your building surveyor or certifier may not focus on this aspect of the work but they may request information to be satisfied that any materials being proposed or used are fit for purpose.

Also talk to your suppliers, manufacturers, and installers to ensure that any material supplied is the correct material for the installation.

To find out more, contact HIA’s Building Services team.

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