Accessibility

Building thresholds are highly trafficked making access and mobility an imperative consideration. Designers must cater for a diverse occupancy driven by a number of factors including an ageing population as well as disability requirements. Level threshold drainage in buildings facilitates access and eliminates the need to have conventional step downs that were once used to contain stormwater runoff.

There are a number of regulatory and user requirements that designers must be aware of when specify drainage channels.

AS 1428.1:2021 includes, Section 4 Floor or ground surfaces on continuous accessible paths of travel and circulation spaces, with Clause 4.4 Grates which states the following:

“Grates in paths of travel shall be in accordance with the following:

(a)  Circular openings shall be not greater than 13mm in diameter.
(b)  Slotted openings shall be not greater than 13mm wide and not greater than 150mm long and be oriented so that the long dimension is transverse to the dominant direction of travel.
(c)  Linear openings shall be oriented so that the longer dimension is transverse to the dominant direction of travel, except where linear openings are less than 8mm wide.  Where linear openings are less than 8mm wide, orientation is optional.”

If the grates meet AS 1428.1, they are deemed to comply with DDA requirements.

To learn more about wheelchair and walking cane compliance, visit ACO’s education pages.

Slip resistance

With the increase in litigation and compensation for injuries caused by slips, trips and falls, designers must consider specifying grates and floor surfaces that comply with AS 4586 – Slip resistance classifications of new pedestrian surface materials. It is important for designers to specify a grate that is relevant for the application with a suitable slip resistance rating.

The perception that a higher slip resistance rating will provide a better solution is incorrect. Trip hazards can be introduced where a grate has a higher slip resistance than the surrounding floor surface, or vice versa. ACO recommends grates to have the same level of slip resistance as the surrounding floor.

The slip resistance of Tile and Brickslot grates depend on the slip resistance of the infill material specified. In order to measure the slip resistance of a grate or floor surface, three tests are specified in AS 4586.

• Wet pendulum: Applied to pedestrian areas that can become wet with rainwater.
• Wet-barefoot inclining platform: Applied to wet areas where footwear/shoes are not worn. For instance at pools, waterparks, beach areas etc.
• Oil-wet inclining platform: Applied for commercial and industrial areas that can be contaminated with oil or grease e.g commercial kitchens.

Slip resistance standards

The National Construction Code (NCC) requires and specifies minimum slip classifications for certain, high-risk areas. The table below is adapted from the National Construction Code 2016, volume 1 and 2.

In 2014, Standards Australia published a supporting handbook, HB 198:2014 Guide to the specification and testing of slip resistance of pedestrian surfaces, which provides recommendations and guidance for specifying surface materials that suit different application requirements. The adjacent table details guidance from HB 198. To assist designers in specifying grates with adequate slip resistance, ACO has commissioned and independent third party authority to test and rate each of its grates to AS 4586.