In a children playground the most underrated component is the one that decides how safe the space really is: the surface underneath the equipment. Beautiful equipment installed over concrete or terrazzo turns every fall into a real risk. This article explains how WINAM designs, installs and accepts poured in place EPDM rubber surfacing for residential, school and public park projects.
What poured in place EPDM surfacing is
Poured in place rubber, also called wet pour, is mixed and laid directly on site instead of being installed as prefabricated tiles. The result is a seamless surface with no joints for children to trip on, and it can follow curves, patterns and logos designed by the landscape architect.
A two layer build up
- Impact attenuating base layer: recycled SBR rubber granules bound with polyurethane. This is the shock absorbing layer, and its thickness determines the safe fall height.
- EPDM wearing layer: virgin EPDM granules, 10 to 15 mm thick, UV stable and colour fast under tropical sun. This is the layer that carries colour and pattern.
Underneath both layers there must be a sound, free draining base: concrete graded at one percent, or a compacted crushed stone base. Skipping the base preparation is the number one reason rubber surfacing delaminates after a single rainy season.
How thick is thick enough
There is no single answer. Thickness follows the free fall height of the equipment, meaning the distance from the highest point a child can stand or hold onto down to the surface. The table below shows the reference values WINAM applies at design stage, based on the principles of EN 1177 for impact attenuating playground surfacing.
| Free fall height | Reference total thickness | Typical location |
|---|---|---|
| Below 1.0 m | 25 to 30 mm | Spring riders, seesaws, toddler zones |
| 1.0 to 1.5 m | 40 mm | Low slides, combination units for ages 2 to 5 |
| 1.5 to 2.0 m | 50 to 60 mm | Standard slides, observation decks |
| 2.0 to 2.5 m | 70 to 90 mm | Climbing towers, tall slides, ladders |
| Above 2.5 m | 100 mm and above | Rope climbers, complex towers |
One point matters more than the table itself: the impact area is not only the footprint directly under the equipment. It must extend at least 1.5 m around the base, and for slides and swings the extension along the direction of travel is considerably larger. This is exactly the area projects cut to save budget, and exactly where accidents happen.
Which evidence proves acceptance
Owners should ask for three groups of evidence rather than relying on a visual check.
- The HIC value, short for Head Injury Criterion. It quantifies head injury severity when a test headform is dropped from the design height. The internationally accepted threshold is HIC below 1000. The test result must correspond to the actual fall height of the equipment installed, not to a generic material certificate.
- Material certification: origin of the EPDM granules, rubber content, heavy metal and volatile compound test results. Children touch this surface with bare skin, so this is not paperwork for its own sake.
- Installation records: measured thickness of each layer at a minimum of five random points, ambient temperature and humidity during the pour, and curing time.
Five common installation mistakes
- Pouring onto a damp base. Polyurethane binder reacts with moisture, producing foaming and loss of adhesion. The surface will lift in sheets within months.
- No drainage fall. Water trapped under the rubber destroys the binder faster than any other factor.
- Thinning towards the edges. Crews often taper the perimeter to save material, yet the perimeter is where children land when they exit a slide.
- Blended EPDM granules. Cheap blends fade within six months of tropical sun, leaving a patchy and brittle wearing layer.
- No expansion gap around posts. Steel posts expand with heat, lift the rubber and crack it in a ring around the base.
Maintenance that delivers full service life
- Weekly: sweep off leaves and sand. Accumulated sand abrades the wearing layer surprisingly fast.
- Monthly: medium pressure wash, and check the edges against kerbs for lifting.
- Quarterly: inspect the zones under slides and swings, the two areas with the highest repeated loading.
- Annually: re measure remaining thickness at worn spots and patch locally before wear penetrates the wearing layer.
A correctly installed and properly maintained EPDM surface delivers eight to twelve years of service life in Vietnamese climate conditions.
Request a design consultation and quotation from WINAM
WINAM supplies children playground equipment, outdoor fitness equipment, park structures and safety surfacing for projects such as Vinhomes Central Park, Feliz En Vista, NovaWorld Phan Thiet, Kenton Node and British Vietnamese International School.
- Hotline: (+84) 9 6161 0202 - (+84) 9 31 176 176
- Email: [email protected]
- Office: 226/4A Le Trong Tan Street, Tay Thanh Ward, Ho Chi Minh City, Vietnam
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