Compare surfaces

We're really talking about playground fall safety applications when speaking about comparing surfaces, and specifically about public playgrounds for data comparison {although there are many advantages to using rubber mulch for landscaping, as well).

 

Playground safety surfaces are designed to absorb fall impacts (referred to as impact attenuation), and there are two primary methods, with a hybrid of both. There's compression and dispersion, with compression meaning the surface depresses, often resulting in a bouncing effect, while dispersion defines a surface which displaces or scatters, to absorb impact force. Then there's a hybrid method that has the best of both compression and dispersion for the best impact attentuation. 

 

The most widely used playground safety surfaces are: A) playground sand (silica), B) EWF (engineered wood fiber), C) rubber mulch, and D) Pour-In-Place (PIP). Playground mats, tiles & synthetic turf with padding have characteristics similar to PIP. There are some hybrids, yet they don't constitute as high percentage as these four. There are characteristics and dynamics about each of these that need to be considered when choosing the most viable safety surfacing for your playground.  

Surfacing synopsis

The five primary elements for playground safety surfacing options involve initial and lifespan expectations for: 1) Cost, 2) Safety, 3) Maintenance, 4) Hazards, and 5) Liabilities. We've distilled each element for the four surfaces into a synopsis, with more detailed info available on each surface's dedicated webpage. 

 

The safest of all playground surfacing options is our rubber mulch, which provides the lowest Head Injury Criteria (HIC) scores tested at the maximum fall height possible of 17 feet! It provides the best impact attenuation through a hybrid of both dispersion & compression with only a 6" depth, lasting for 25 years or more. Playground sand and engineered wood fiber (EWF) require a 12" installation depth that offers much lower fall heights and HIC scores than rubber mulch, with sand providing the dispersion method of impact absorption, and EWF providing the hybrid method initially and when properly maintained (yet it rarely is in reality, so lowered rates of dispersion & compression are common), and both attract unwanted pests and liabilities over a relatively short lifespan (the NRC recommends replacing playground sand or EWF every two years if not used indoors, unless it's protected from access by birds or animals!). Pour-In-Place (PIP) is definitely the most expensive, least safe, comes with the highest and most costly maintenance, arguably the one surface that has the most hazards and liabilities, which increase over its relatively short lifespan, with comparatively high cost to install and maintain. 

Conclusions

Our rubber mulch provides the highest level of impact attentuation and ADA compliance that remains the same over 25 years or more, for an initial cost of about $5 per square foot, with very little to no maintenance required at no more than half of the initial installation cost over its lifespan. Playground sand and EWF provide varying degrees of fall safety and ADA capabilities over their relatively short life expectancy, with an initial cost of slightly less than rubber mulch, yet each with a host of potential hazards and liabilities, requiring frequent periodic maintenance and replacement with the related costs over the same 25 years or more our rubber mulch lasts. PIP is by far the most expensive and least safe surfacing option that's unfortunately still chosen due to its appearance alone, costing about $12 to $15 or more per square foot initially, requiring high levels of expensive maintenance in heavy traffic areas ranging from $2 to $3 per square foot every two to three years on average, likely lowering the relative impact attentuation each time, and also coming with a plethora of hazards and liabilities.