How Thick Should Wet Pour Playground Rubber Be? | EPDM Surfacing Guide

When designing a playground or sports zone, thickness isn’t just a number—it’s the difference between safe and unsafe. Wet pour rubber needs to meet both comfort and critical fall protection standards.

Wet pour rubber should be 15–60mm thick, depending on the type of area, fall height, and safety standards like EN1177 or ASTM F1292.

Standard Thickness Guidelines by Application

👉 Related reading: Understanding EN1177 Certification

What Determines Wet Pour Rubber Thickness?

• Critical Fall Height (CFH): The height from which a child could fall. This is the main safety benchmark.
• Area usage: Play zones need thicker layers than walkways.
• Sub-base type: Softer or flexible sub-bases may require more thickness to avoid bottoming out.
• Drainage requirements: Paths or outdoor areas with poor drainage may use slightly thicker rubber to maintain grip.

Do Safety Standards Define the Thickness?

Wet pour rubber thickness must meet safety standards like EN1177 (Europe) or ASTM F1292 (USA). These standards link the critical fall height (CFH) to required shock-absorption performance.

For example:

• CFH of 1.5m requires approx. 40mm–50mm total system thickness
• CFH of 2.0m may require 60mm or more depending on base

Certified installers often provide test results based on on-site drop tests to verify compliance.

👉 Learn more: What Certifications Should Playground Flooring Have in Europe?

EPDM Layer vs Total System Thickness

Wet pour systems are layered:

• Base Layer: Usually recycled SBR rubber, 20–50mm thick
• Top Layer: Colored EPDM granules, 10–15mm thick

Total system thickness = base + top. Budget-friendly systems may reduce EPDM to 5mm, but we recommend at least 10mm for durability and color retention.

👉 More about material: EPDM Granules

Does Location Affect Wet Pour Thickness?

Yes. In hotter regions, UV resistance is key—thicker EPDM layers last longer. In cold areas, extra thickness helps absorb freeze-thaw shock and reduces surface cracking.

In humid or rainy regions, proper drainage layers or increased slope design are critical to maintaining surface performance.

Mistakes to Avoid

• Applying only a thin decorative EPDM layer with no shock-absorbing base
• Using same thickness across all zones (ignoring fall height zones)
• Skipping site drainage checks—can cause pooling and freeze damage
• Using low-density or crumb fillers to "fake" thickness

Related Blog Posts

• How Long Does Wet Pour Rubber Last?
• Choose the Right EPDM Granules
• How to Install Outdoor Rubber Flooring
• Is Rubber Flooring Safe for Outdoor Playgrounds?

Frequently Asked Questions

Q1: What is the minimum thickness for wet pour rubber?
A: For non-fall areas like paths, 10mm–15mm is standard. For safety zones, a minimum of 40mm is recommended.

Q2: How thick should wet pour be under swings or slides?
A: These are considered high fall zones. Wet pour thickness here should be at least 50mm.

Q3: Is thicker always better?
A: Not necessarily. It should be matched to the intended use and fall height. Too thick may cost more and offer no added safety.

Q4: Can I install 15mm wet pour on compacted soil?
A: No. Wet pour needs to be installed over solid sub-bases like concrete or asphalt for proper bonding and durability.

Q5: Does thickness affect cost significantly?
A: Yes. Every 10mm increase adds both material and labor costs. Budget planning is important.

Conclusion

Choosing the right thickness is not only about meeting standards—it’s about ensuring safety, comfort, and durability for years to come.

Need a quote for your project or unsure how thick your surface should be? Contact us or explore www.lanhefloor.com to speak with our technical team.