Playground surfaces compared: padded turf, rubber mulch, wood chips and pea gravel

01How far can a child fall onto each surface?

Playground surfacing is rated by its critical height: the tallest fall it is expected to protect against a life-threatening head injury, found with the ASTM F1292 drop test. The U.S. Consumer Product Safety Commission (CPSC) says that rating should be at least the fall height of the tallest equipment, measured from the highest platform a child stands, sits or climbs on (CPSC public playground handbook).

The depths are the CPSC’s 2025 figures for loose fill that hasn’t been impact-tested. Its home playground handbook keeps it simpler: 9 inches of wood chips, engineered wood fiber or rubber mulch for equipment up to 8 feet, and sand or pea gravel only up to 5 feet.

Two things the table leaves out:

• Coverage. At home, the CPSC says surfacing should run at least 6 feet past the equipment on every side, and in front of and behind a swing to twice the height of the top bar.
• Bare turf. The CPSC doesn’t count grass or dirt as protective surfacing, and says carpeting and mats aren’t appropriate unless tested to F1292. Turf rolled straight over a compacted base falls in that carpet-and-mats group; the pad under it, tested with the turf, is what earns a rating.

Matching a pad to a platform is on our playground turf page; anchoring a set through turf is in putting a swing set on artificial turf.

02What does a Northern Colorado winter do to loose fill?

It freezes it. The CPSC says most loose fill that freezes solid no longer works as protective surfacing, even when the top few inches still feel loose, and recommends keeping children off the equipment then. The nearest NOAA stations average 150 days a year with a low at or below 32°F at Fort Collins, and 177.7 at Longmont 2 ESE (1991–2020 normals).

Frost isn’t the only problem:

• Thaw, then freeze again. Chinook winds can raise the temperature 25 to 35°F in a short time, the Colorado Climate Center says. Snowmelt that soaks into chips by day can lock up again after dark.
• Water that stays. The CPSC calls drainage essential for loose fill: standing water cuts its protection and speeds compaction and decomposition, and wet mulch packs faster than dry. Longmont says its clay soils absorb water slowly, and Greeley describes hard clay sometimes just inches down. A mulch bed dug into clay needs a way for water out.
• Wind. The CPSC lists wind among the things that lower a loose fill’s rating, and the Climate Center describes periodic, severe turbulent winds close to the mountains.
• Settling. Loose fill compresses at least 25% over time, which is why the 9-inch depths start at 12.

In practice: mark the target depth on the playset posts, as the CPSC suggests, and rake back after storms and busy weeks. Swings and slide exits lose fill fastest. In a U.S. Access Board-funded study of 25 new public playgrounds, a kick-out hole at a swing in engineered wood fiber could reach 3 by 8 feet and more than 5 inches deep within the first year.

03Is rubber mulch safe under a swing set?

For falls, it holds up: the CPSC credits 6 compressed inches of rubber mulch with a 10-foot critical height, and rubber doesn’t compress the way wood does. The open question is chemical. The CPSC’s 2025 handbook says untested rubber mulch made from recycled tires may contain hazardous metals or other substances of concern, should be kept off toddler playgrounds, and should be used only if it meets ASTM F3012.

EPA says the CPSC will carry out a risk assessment of children’s exposure to playground surfaces made of tire rubber; none had been posted as of this page’s check date.

04What does padded turf do better, and what should you check?

Padded play turf is a unitary surface: turf over a shock pad, sometimes with infill, rated as one system. It doesn’t kick out from under swings or need raking back to depth, and it can double as an accessible route. Under the ADA play-area guidelines, ground on an accessible route at a park, school or childcare facility must meet ASTM F1951. When the Access Board wrote its guide, rubber surfacing and some engineered wood fiber met it, and wood fiber needed frequent upkeep to stay compliant. In the study above, an artificial turf system was among the hybrid surfaces with minimal problems after a year, about level with poured rubber; the authors still concluded there is no perfect playground surface.

Where it falls short:

• Heat. A 2022 study of 10 Sydney playgrounds found dark poured rubber and synthetic turf the hottest ground surfaces, both peaking above 80°C (about 176°F); in shade, no surface reached burn temperatures. The CPSC warns that dark surfaces in intense sun have blistered bare feet. The nearest NOAA station to Longmont averages 48.8 days a year at or above 90°F. Plan shade before choosing the turf; more in how hot artificial turf gets.
• A lab rating is a starting point. ASTM F1292 rates surfacing in a lab, as received. Wet and frozen tests are optional, and the standard itself says a lab rating doesn’t account for freezing, moisture, compaction or loss of thickness.
• Looks prove nothing. In the Access Board study, a new poured-rubber surface that looked fine failed a field impact test at two swing bays. The CPSC recommends field-testing installed surfacing to ASTM F3313.

What to ask an installer for, and what a good answer looks like:

• The F1292 report for the exact turf, pad and infill combination, showing a height at or above your set’s fall height. A good answer names the pad and hands you the report.
• Whether that system was also tested wet or frozen, and to what height.
• A drawing of the padded area: 6 feet past the set on every side, and the swing zone front and back.
• For a daycare, school or HOA park: the F1951 report, and an F3313 field test after the install.

05What are Northern Colorado parks putting under playgrounds?

Parks work from the CPSC’s public handbook and the ADA. Their choices aren’t rules for a backyard, but they show the direction:

• Frederick’s park design standards accept poured-in-place rubber, playground turf and, only at fitness areas or climbing boulders, engineered wood fiber. They prohibit rubber tiles, pea gravel, sand and shredded rubber mulch. Playground turf there must be a system of turf, shock pad and infill that meets head-impact criteria as a whole, with no rubber infill, an underdrain, and suitability for falls up to 12 feet.
• Greeley’s replacement playground at Twin Rivers Community Park uses synthetic turf as its primary accessible play surface, with construction expected to finish in mid-to-late October 2026 (Speak Up Greeley).
• Johnstown is replacing the mulch under both play areas at Sunrise Park with poured-in-place rubber (council packet), and both options priced for Hays Park swapped wood fiber for poured rubber.
• Wellington’s 2026 parks plan calls for poured-in-place surfacing on all new playgrounds (master plan appendix).
• Pea gravel is the listed playground base at Milliken’s Florence Park and at Letford Park in Johnstown’s parks plan.

06Do daycare and HOA playgrounds follow different rules than a backyard?

Yes. This section is not legal advice. The CPSC’s home handbook is guidance, not a mandatory standard, and it sends parks, multifamily housing, public child care and recreational developments to the public handbook. For a family’s own playset, the CPSC’s numbers are the target to aim for.

Child care. Colorado’s child care licensing rules require loose fill to be raked regularly to keep at least 6 inches of depth, and accept turf with a built-in resilient pad as a solid surface when the maker documents that it meets federal safety standards (8 CCR 1402-1-2.230). The ADA play-area guidelines reach childcare facilities too, except family childcare in the provider’s own home.

Common areas. Colorado’s 2025 amendment keeps functional turf allowed and defines it to include playgrounds (HB25-1113). Town codes can go further: Evans’ code says artificial turf is not acceptable for public or common areas (more on Evans). Elsewhere, it depends on the town’s code and the development’s approvals: ask that town’s Planning department before an HOA board votes on turf under a common-area playground.