Welcome back to our Q & A blog series. Today we will be talking about rubber mulch and heat, specifically, the answer to the question “Does rubber mulch get hot in the sun?” On a hot summer day in full sun, everything from beach sand to your car’s leather seats can get uncomfortably warm. How does rubber mulch fair on those heat wave days?
MYTH — Rubber mulch is hotter than wood mulch. FACT — Rubber mulch is no hotter than most surfaces.
All things on a playground will get hot in the sun. Most playgrounds have metal ladders, stairs, monkey bars, etc. that will get hot to the touch. Rubber mulch is no exception. However, rubber mulch does not get hotter than any other play surface. In fact, because it is rubber and does not conduct heat, the mulch under the surface is cooler than other types of material.
The human body registers a pain response to temperatures over 111°F. Surfaces of most playground materials, including wood, sand, concrete, asphalt and rubber mulch, will all exceed this threshold by 15 to 20 degrees on a hot day. This means that caution should be taken on playgrounds, regardless of surface materials, on hot days. According to rubbermuch.com
In weighing the safety issues, it would appear that although caution should be taken under certain weather conditions and in relation to very small children in particular, the risks associated with serious injury don’t appear to be any more significant than many other common outdoor surfaces.
In regards to landscaping, rubber mulch is an excellent insulator for the soil. As only the surface level of the mulch will absorb heat, the roots of the plants are protected from hot summer days. In the winter, the rubber mulch helps to insulate the ground against frost and snow.
A study performed by the American Society of Agricultural Engineers concluded that tire chips (rubber mulch) showed less than 1% transfer between the testing plates. For traditional mulch or straw, the transfer only reduced when more mulch material was added to the testing area. This means that rubber mulch requires less material to insulate the roots of plants against temperature changes.
We hope this has answered some questions regarding rubber mulch and heat. When out playing in the sun, use caution and stay hydrated to prevent heat-related issues. For more of our Q & A series, check out yesterday’s topic on Toxicity.