AUST – HENDRY building surveyors advise that the 2014 Building Code of Australia (BCA) has introduced criteria for the slip resistance of treads or tread nosing strips and stair landings. Slip resistance must be shown to comply with AS 4586. The table below specifies the required rating to be achieved.
|Tread or landing surfaces||P3 or R10||P4 or R11|
|Nosing to tread or landing edge||P3||P4|
It is common practice to use nosing strips on treads and stair landing in order to achieving compliance with the BCA.
The introduction of “Add-on” nosing strips can pose an additional risk that must be considered. This is because a tripping hazard can be inadvertently introduced. A trip hazard can occur due to the raised lip of the introduced nosing strip and the fact that the nosing strip must be placed on the tread at the location where a trip risk is most probable.
Therefore nosing strips must be well chosen in conjunction with the stair material so that they together achieve a smooth transition and visual clarity of each tread.
Some guidance can be obtained through reference to AS 1428.1 which specifies tolerances relating to the abutment of different surface (Ref cl 7.2). Additional guidance is given in cl 11.2 of AS 1428.1.
Good practice suggest that in order to avoid a trip potential, the nosing strip needs to be inset to a sufficient depth that the sharp bevelled transition of the strip’s edge is at least 5mm x 5mm with a level difference not exceeding 2mm between the abutting surfaces on the tread or landing.