AS 4586 Slip Resistance: The P-Rating Your Carpark Ramp Actually Needs

A shopping centre in Frankston called us after a slip and fall incident on their entry ramp.

Someone had gone down on a wet day. The incident was being investigated. The centre's insurers were asking questions. And the operations manager was in the middle of realising that nobody had ever properly documented the slip resistance rating of the ramp surface or the line marking on it.

The ramp had been remarked two years earlier by a general line marking contractor who'd used standard carpark paint. No slip resistance testing. No documentation. No consideration of whether the paint met AS 4586 requirements for a wet ramp surface.

In the context of a personal injury claim, that documentation gap is a serious problem. You can't prove compliance if you never measured it.

We came in, tested the surface, documented the findings, and provided a recommendation. It was too late to prevent the incident. But the centre now has proper slip resistance documentation for every painted surface on their property.

Here's what you need to understand about slip resistance before your next line marking job.

What Is AS 4586 and Why Does It Matter for Line Marking?

AS 4586:2013 is the Australian Standard for slip resistance classification of new pedestrian surface materials. It defines how surfaces are tested and categorised based on their slip resistance under dry and wet conditions.

Here's the bit that catches people out: line marking paint is a surface material. When you apply paint to a carpark ramp, pedestrian crossing, or wet area, you're changing the slip resistance characteristics of that surface. Standard carpark paint typically has lower slip resistance than the unpainted concrete or asphalt beneath it.

In wet conditions, a freshly painted ramp can actually be more slippery than a worn unpainted surface. That's not a hypothetical — it's physics. And it's why AS 4586 matters.

Understanding P-Ratings

AS 4586 uses a Pendulum Test Value (PTV) measured by a standardised pendulum friction tester to classify surfaces into P-ratings. The P stands for Pedestrian.

The P-Rating Scale

• P0: PTV below 12 — extreme slip risk. Not suitable for pedestrian use in any wet area.
• P1: PTV 12-24 — high slip risk. Suitable only for dry areas with permanent footwear.
• P2: PTV 25-34 — moderate slip risk. Suitable for low-risk dry interior areas.
• P3: PTV 35-44 — low slip risk. Suitable for external areas and areas that may become wet.
• P4: PTV 45-54 — very low slip risk. Suitable for ramps and areas regularly wet in use.
• P5: PTV 55+ — excellent slip resistance. Required for ramps with grades over 1:14 in wet conditions.

For context: most internal dry carpark surfaces need a minimum of P3. External pedestrian areas need P3-P4 depending on gradient and exposure. Ramps need P4-P5 depending on gradient and whether they get wet.

Where P-Ratings Apply in a Typical Carpark

Entry and Exit Ramps

This is the highest risk area. Vehicle ramps get wet from rain and from wet vehicles. Pedestrian paths adjacent to or crossing vehicle ramps are exposed to water splash. The NCC and AS/NZS 1428.1 both reference AS 4586 for pedestrian surfaces in these areas.

A ramp gradient of 1:5 to 1:8 with regular wet exposure needs a minimum P4 rating on any pedestrian surface. If the ramp is in a fully exposed outdoor location and steeper than 1:8, P5 is the appropriate target.

Standard carpark line marking paint applied to a smooth concrete ramp will typically achieve P2-P3 in dry conditions and potentially P1-P2 when wet. That's not adequate for a wet ramp. You need either a non-slip aggregate added to the paint, an anti-slip paint formulation, or a different marking approach entirely.

Pedestrian Crossings Within the Carpark

AS 1742.10 specifies that pedestrian crossing surfaces should maintain adequate slip resistance under likely conditions. In a carpark context, that means accounting for wet weather, oil contamination, and the fact that crossings are typically in areas of vehicle movement.

We specify P3 minimum for internal carpark pedestrian crossings and P4 for external crossings that are exposed to weather.

Accessible Parking Bay Shared Areas

AS/NZS 2890.6 requires that the shared area adjacent to accessible parking bays be level (maximum 1:40 gradient). It also references slip resistance requirements because the shared area is specifically designed for wheelchair users and people with mobility aids — populations where a slip event can have serious consequences.

P4 is the appropriate minimum for accessible bay shared areas.

Loading Dock Areas

Loading docks are wet, contaminated, and subject to heavy foot traffic from workers in various footwear. P4 is the minimum for loading dock pedestrian areas. P5 for any ramp access to loading docks.

The Practical Problem: Standard Paint vs. Slip-Resistant Paint

Most line marking contractors use standard waterborne road marking paint. It's cheaper, faster to apply, and perfectly adequate for dry carpark bays and road centre lines.

It is not adequate for wet pedestrian surfaces, ramps, or accessible areas.

For those applications, you need either:

• Anti-slip paint: formulated with fine aggregate already included, typically achieving P3-P4 on standard surfaces. More expensive per litre but dramatically better in wet conditions.
• Aggregate broadcast method: standard paint applied first, then fine sand or aluminium oxide aggregate broadcast into the wet paint, then a second coat applied over the top to lock the aggregate in. Achieves P4-P5 reliably. Our preferred method for high-risk areas.
• Thermoplastic with aggregate: thermoplastic material with glass beads or anti-slip aggregate incorporated. Used for external applications where durability and slip resistance both matter. Lasts 5-8 years.

The cost difference between standard paint and a properly specified anti-slip application for a carpark ramp pedestrian crossing is usually a few hundred dollars. The cost of a slip and fall personal injury claim is considerably more.

Testing and Documentation: What You Need

If you ever face a personal injury claim related to a slip on a painted surface, the first question your insurer and your solicitor will ask is: what was the slip resistance rating of the surface, and how do you know?

'The contractor painted it' is not a sufficient answer.

What you need is a test certificate or material data sheet demonstrating the P-rating of the applied surface. For products we specify, we can provide manufacturer data sheets showing the tested P-rating. For critical applications like ramps and accessible areas, we can arrange post-installation pendulum testing and provide a signed test certificate.

We make it a standard practice to include material specifications in every job completion package. You should be asking for this from any contractor doing line marking in wet or pedestrian-exposed areas.

A Practical Checklist for Facility Managers

• Have you identified all pedestrian surfaces in your facility that get wet?
• Do you know the current slip resistance rating of your ramps and wet pedestrian areas?
• Do you have material documentation from your last line marking job?
• Are any accessible parking bay shared areas marked with standard paint rather than anti-slip?
• When was your last remarking job? Standard paint in high-traffic wet areas degrades faster than the visible wear suggests.

If you're answering 'not sure' to any of those, it's worth getting them documented before an incident makes the question urgent.

Frequently Asked Questions

Does AS 4586 apply to line marking paint specifically or just to surface materials?

AS 4586 applies to all pedestrian surface materials, including coatings applied to existing surfaces. Line marking paint applied to a pedestrian area creates a new surface with its own slip resistance characteristics. That surface needs to meet the P-rating appropriate for its location and use.

How do we know if our current markings meet the required P-rating?

The only way to know for certain is to test them with a pendulum tester or obtain the material data sheets from whoever did the marking. We can arrange pendulum testing for any surface — call Niel on 0417 460 236.

Is anti-slip paint more expensive?

Per litre, yes. Per job, the difference is often smaller than you'd expect because anti-slip applications typically use a more efficient aggregate broadcast method rather than multiple paint coats. And the longevity is generally better — the aggregate surface wears more slowly than standard paint. We'll include material specifications in every quote so you can see exactly what you're getting.

Can we add slip resistance to existing markings without full removal?

In some cases, yes. An anti-slip top coat can be applied over existing sound markings to improve their P-rating. This works better on some surfaces than others. We'll assess the existing surface condition before recommending this approach — applying a top coat to delaminating or heavily worn marking isn't going to give you reliable results.

What P-rating does a car park ramp need?

A car park ramp that gets wet needs at least a P4 slip rating under AS 4586:2013 on any pedestrian surface, and P5 for higher-risk ramps. Line Marking Australia uses anti-slip paint, an aggregate broadcast method or thermoplastic with aggregate on ramps, instead of standard car park paint.

What documents should I keep after line marking a ramp?

Keep a test certificate or material data sheet showing the P-rating of the applied surface, the product used and the date it went down. Line Marking Australia includes material specifications in every job completion package, so you can answer an insurer or solicitor if a slip claim is ever made.

Line Marking Australia. Since 2009. 5,000+ projects completed. $20M public liability. $10M professional indemnity. Full material documentation on every job. Niel Bennet, Director — 0417 460 236.

Related reading: Carpark Line Marking · Accessible Parking Line Marking · Line Marking Removal · Thermoplastic Line Marking · AS/NZS 2890.6 Guide · DDA Compliance Checklist · Line Marking Melbourne · Line Marking Sydney