Stair Tread Nosings and Luminance Contrast


The Fundamentals of Luminance Contrast

Stair tread nosings need to stand out from the surrounding parts of the stairs. This is an important safety issue to ensure the visibility and safe usage of steps and stairs by vison-impaired pedestrians. The “Luminance” of a surface measures brightness. The degree of visibility of one surface against another is measured as “Luminance Contrast”.

Luminance Contrast is the ratio of the Luminance Reflectance Values (LRV) of a particular colour and style of Stair Tread Nosing and the surface on which it is installed. There is an industry-standard formula which is used to calculate the degree of contrast in every case. The Standards AS 1428.1 -2021 and AS 1428.1 – 2009 both set the minimum Luminance Contrast for compliance.

Clearly, both the LRV of the floor surface and the LRV of the Stair Tread product must be known, or there is no way to calculate the contrast. Both possible combinations, of dark stair tread nosings on light floor coverings and light stair tread nosings on dark floor coverings, can deliver Standard-compliant contrast values.

The simple solution

Lathams provides a user-friendly way to determine which of our abrasive insert colours will provide a compliant degree of contrast given the LRV for your chosen floor surface. We have set up a simple tool to interpret the calculations for you. This tool has been included on many stair tread nosings product pages. The user enters the LRV for their floor surface. The contrast between that LRV and the Latham products in their possible colours is calculated. We display only those Stair Tread Nosing colours which will deliver at least the minimum contrast requirement under the standard.

You can find the Luminance Contrast calculation tool here:

Latham Luminance Contrast Calculation Tool


How we know the LRV of Lathams’ products

Lathams’ Silicon Carbide abrasive infills are offered in a variety of colours, in combination with our selection of different metal tread profiles. This gives our customers the widest range of product choice in the industry. We have engaged the NATA-accredited Optics and Radiometry Laboratory at the University of NSW School of Optometry and Vision Science to conduct independent determinations of the Luminance Reflectance Values of all our possible combinations.

This laboratory testing provided an independently determined Luminance Reflectance Value for all the Latham stair tread nosing products. The specific values for each combination of tread style and infill colour can be found here: Asbra Safety Stair Treads Luminance Testing Information

That information gives you all that you need for the Stair Tread Nosing part of the calculation. Once you know the LRV of your chosen floor surface, you can calculate the contrast using the method in the Standard. Or you can just use our simple calculator tool to present you with only the compliant colours for use with that flooring.

How can you know the LRV of a flooring surface?

Sometimes, although it is rare, the supplier may publish the LRV for their flooring surface. Some professional architecture and design practices have invested in their own spectrophotometer equipment, but this can be extremely expensive, especially for small firms with irregular need to know these facts.

Lathams can help!

Lathams have, in our Sydney plant, a Spectrophotometer capable of taking the readings necessary as detailed in AS 1428.1-2009 Appendix B and AS/NZS 1428.4.1:2009 Appendix E. Lathams’ instrument is properly maintained and calibrated by a NATA Accredited Authority. 

When builders and architects ask us, Lathams can provide indicative luminance testing results for samples of your chosen flooring. We will provide the test results and the luminance contrast between the supplied sample and our stair tread nosings or Tac Tile indicators.

You can send us a request here to have Lathams test the LRV of your floor finish. We can also, if you like, indicate which colours of Latham Stair Tread Nosings will meet the Luminance Contrast requirements of the Standard when used with the tested floor surface.

Find out more about this service or request more information on LRV testing by Latham Australia. Simply email

Further Technical Background to this topic

Asbra Safety Stair Treads Luminance Testing Information

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