What is Luminance and why consider it?
Luminance can be defined as a measure (in candelas per sq. metre) of the brightness of a point on a surface that is radiating or reflecting light.
Sufficient luminance contrast of surfaces can visually warn people of impending hazards such as kerb ramps, stairs, bus stops and railway station platform edges. Using colour on or within concrete can greatly assist in improving the luminance factor of these areas, particularly for visually impaired people.
Luminance and Building Requirements
The Building Code of Australia (BCA) includes the Australian Standards for access and mobility, AS 1428.1 which requires that surfaces required to comply with disabled access, have sufficient luminance contrast such as stair nosings to clearly delineate the step edge.
Testing the luminance of your building will help to ensure that your building complies with disabled access requirements for visually impaired people. Luminance Contrast Testing involves testing the difference in how black or white a colour is (luminance reflectance) compared with adjacent colours, using a colour meter. A formula is then used to determine the contrast using the two luminance reflectance values.
Concrete Colour Systems CCS has completed extensive luminance testing on standard CCS colours and the impact of differing surface textures and sealers. Where stone/aggregate is present, for example exposed aggregate, honed or sandblasted surfaces, the type of aggregate and the level of the exposure can significantly impact on luminance values. To better understand luminance values for decorative concrete or to access wet and dry values, please contact the CCS Helpline on 1800 077 744 or email firstname.lastname@example.org.