Specifying slip resistant surfaces in NZ
The NZ Building Code, D1/AS1 states that adequate slip resistance is required on all public access routes, including access into and within buildings.
About 45 New Zealanders die every year resulting from a fall on the same level due to ‘slipping, tripping or stumbling’. Injury from all types of fall is the major cause of hospitalisation for injury in New Zealand. These statistics show the importance of providing safe walking surfaces in buildings to protect building users from slipping and tripping.
NZ's Building Code Clause D1 Access Routes requires that access routes 'have adequate slip-resistant walking surfaces under all conditions of normal use.' Acceptable Solution D1/AS1 of the D1 Compliance Document in Paragraph 2 requires a friction coefficient of 0.4 for level access routes used by the public. For houses, this includes only the route to the main entrance. For up to date information, see: http://building.govt.nz/codewords-19-article-1
Adequate slip resistance: defined as meeting a co-efficient of friction of not less than 0.4 when tested in accordance with AS/NZS 3661.1. When a surface will remain dry under normal usage, almost all surfaces will provide adequate slip resistance and do not need to be tested. When a surface may get wet under normal circumstances, it should be tested under AS/NZS 3661.1 to prove its suitability.
Residential: Commonly, the route to the main entrance would usually get wet under normal circumstances, a tile that passes 0.4 co-efficient of friction when wet is required. For single dwellings decks, pool areas, bathrooms and laundries are not public areas and therefore are not required to be slip resistant.
Commercial: If an area within a commercial space could become wet during normal use, again a co-efficiency of friction of 0.4o and above is required
Standards in NZ
The AS/NZS 3661.1 is the slip resistance standard in NZ and referenced under the NZ Building Code in D1/AS1 of the D1 Compliance Document.
Also worth noting in regards to the NZ industry is the alternative Australian testing for rating slip under AS/NZS4586 which uses a ramp method of assessing the slip rating. These tests give a "R" rating (R9, R10, R11 etc). In some circumstances these ramp tests may be more suitable for NZ situations, for example the 'wet barefoot' test may be more applicable in swimming pool areas. The ramp method of testing is not recognised under AS/NZS3661.1 or the NZ Building Code, but could be applied to be used as an alternative solution.
Flooring Applications: Commercial
Commercial bathrooms are not considered to be a wet area, so do not require a slip resistant tile unless the bathroom is prone to wetness due to the addition of tiled showers.
With regards to commercial kitchens and safe flooring, a non-slip tile that is easy to clean surface is recommended alongside non-slip mats.
For more detail on suitable flooring options for Commercial spaces, you are welcome to contact our technical experts.
What is Accelerated Wear testing?
Accelerated Wear is a method of testing tiles to project their non-slip properties into the future. It uses cycles of scouring across a surface to replicate foot traffic, and then re-tests slip resistance at 500, 1000 and 5000 cycles. It is not compulsory under the NZ Building Code, but as many non-slip tiles decrease in slip resistance dramatically after installation Accelerated Wear testing prior to specification provides assurance that the surface will maintain its non-slip properties.
Sustainable Slip Resistant tiles are tiles that initially pass the co-efficient 0.4 slip requirement and go on to maintain their slip resistance over a period of time. Tiles that sustain their slip resistance over the longest period are typically specifically manufactured with this objective. It is impossible to predict how long slip resistance will be maintained for, as this depends on location-specific factors such as cleaning methods and foot traffic. Slip resistance experts Safe Environments (Australia) recommend a surface achieve a minimum BPN of 35 after wear (either in-situ or accelerated) to be classified as effectively slip resistant.
BPN is the test result reported from pendulum testing under AS/NZS4586. It can be converted with a formula into the co-efficient figure required under AS/NZS3661.