Slip resistance is a crucial consideration in architectural design, particularly for external spaces such as roof terraces, balconies, and ramps. Ensuring safe pedestrian surfaces minimises the risk of slips and falls, helping architects create functional and compliant spaces. One of the most reliable ways to assess slip resistance is through BS EN ISO 16165:2021, the European standard for evaluating pedestrian surface safety.
Understanding BS EN ISO 16165:2021
BS EN ISO 16165:2021 provides a standardised framework for assessing slip resistance in pedestrian areas. It includes four primary test methods:
- Ramp Test: Evaluates slip resistance on a sloped surface using either bare feet or shoes.
- Pendulum Test: Uses a swinging pendulum device to measure friction and is considered the most accurate and widely accepted method.
- Tribometer Test: Measures the dynamic coefficient of friction between a slider and the surface.
- Dynamic Friction Test: Determines the force required to move a slider across the surface.
Each test method has its advantages and is selected based on specific application needs. Among these, the Pendulum Test is the most commonly used and internationally recognised for its reliability and accuracy.
The Pendulum Test Method
The Pendulum Test, outlined in Annex C of BS EN ISO 16165:2021 (formerly BS 7976:2002), simulates real-world walking conditions. The process involves:
- A pendulum device with a rubber slider mimicking a shoe heel striking the floor.
- The pendulum swings, making contact with the surface.
- The Pendulum Test Value (PTV) is calculated based on the swing’s deceleration, indicating the level of slip resistance.
A higher PTV signifies greater slip resistance, with the Health and Safety Executive (HSE) recommending a minimum of 36PTV for external applications to ensure a low risk of slips.
Slider Types in the Pendulum Test
BS EN ISO 16165:2021 recognizes two primary slider types to simulate different walking conditions:
- Slider 96 (Shod Applications): Represents shoes and is used for most indoor and outdoor environments.
- Slider 57 (Unshod Applications): Mimics barefoot walking, essential for wet areas such as poolside applications.
Selecting the appropriate slider ensures realistic and targeted safety assessments for different environments.
Specifying Slip Resistance for Roof Terraces and Balconies
When designing external spaces, architects must specify materials and finishes that maintain high slip resistance, particularly in wet conditions. Consider the following:
1. Testing Standard & Method
- Reference BS EN ISO 16165:2021 explicitly.
- Specify the Pendulum Test Method for reliable assessment.
2. PTV Requirements
- High-traffic areas: Aim for PTV >40 to accommodate frequent use and potential contaminants.
- Low-traffic areas: May require a slightly lower PTV (36PTV minimum)
- Ramps: Require a higher PTV due to increased slip risk.
3. Wet & Dry Conditions
- Conduct tests in both dry and wet conditions to replicate real-world scenarios.
- Consider potential contaminants like algae, grease, or water.
4. Material Selection
Choose materials known for slip resistance, such as:
- Anti-slip ceramic tiles
- Textured natural stone
- Specialized concrete finishes
- Non-slip decking materials
5. Installation & Maintenance
- Ensure proper installation to maintain slip resistance.
- Include maintenance guidelines to prevent contaminants from reducing surface grip.
6. Example Specification
“The external roof terrace and balcony surfaces shall be constructed of [Material Type] with a minimum PTV of [Value] when tested wet and dry in accordance with BS EN ISO 16165:2021 using [Slider Type] slider.”
Designing Safe Ramps for Roof Terraces
Ramps present a unique challenge in slip resistance, as their slope increases the risk of slipping, especially when wet. To address this:
- Higher PTV requirements: UK Slip Resistance Group suggests an increased value based on the ramp’s slope angle.
- Material selection: Use textured surfaces like anti-slip coatings.
- Regular maintenance: Prevent contaminants from reducing friction.
UK Slip Resistance Group’s Recommended Formula
Minimum Slip Resistance Value + [100 x Tangent (Slope Angle)]
For example:
- A 5-degree slope requires a minimum slip resistance of 45PTV.
- A 1:20 ramp should have approximately 41PTV.
Conclusion
By implementing BS EN ISO 16165:2021 guidelines and specifying appropriate slip resistance measures, architects can ensure safe, durable, and compliant pedestrian surfaces. Thoughtful material selection, rigorous testing, and ongoing maintenance contribute to creating spaces that prioritize user safety while meeting design aesthetics.
