Wood is such an important material in natural play. It can be used in endless combinations and configurations; climbing, walls, fences, loose parts, edging, seating, etc. But wood is, at its essence, a natural material that degrades and changes fairly quickly with use and time. How long a wood element in a playground will last depends on a lot of factors; is it touching the ground, how much wear will it get, how big is it, has it been treated, what is the local climate, and what is the intended use or actual use.
I would like to think that wood should be used in a capacity that it is allowed to degrade and change, further exemplifying natural processes. But, with safety requirements this seems more of a dream then a functional reality. I believe this striving for long lived materials is what resulted in the plastic, fiberglass, and steel pieces we see today.
THE CASE STUDY
I recently visited a natural playground in Tampa Florida. The playground was designed by The Natural Playground Company. If you have not seen their work you should! They were not involved in the construction, so final wood choices and details were completed by the contractor. Ethan King from The Natural Playgrounds Company told me the following.
"We find a minimum of 5 years before any degradation occurs(on wood pieces), typically closer to 10. That's only 5 years less than traditional equipment. Furthermore, rotting logs don't cause splinters so there really isn't any kind of a significant safety concern."
Natural Playgrounds Company now treats all their products with a treatment called soy seal. They recommend treating wood ever 6 months in tough climates. I have been using Timber Pro's internal wood stabilizer for park and play elements.
The Tampa play space is set in a unique Cottonwood grove. As an Oregonian it looked very 'Florida' with lizards, hanging moss, and an overall mangrove feel. Most of the elements are wood and the overall feel was magical woodland like. Today I am going to take a closer look at the wood elements.
|From Natural Playgrounds http://naturalplaygrounds.com/|
SUCCESSFUL LUMBER BASED PIECES
The following pieces seem to be constructed from lumber or dimensional piecesinstead of logs. Overall they seemed to be holding up well.
|Coat rack: made from a 4" x4" and round pegs|
|Climber post - made from a 6" round (maybe a fence post) and 1" pegs. It could still hold my weight!|
|Storage Cabinet - dimensional 1 and 2 by material|
|Dimensional lumber trellis and swing.|
DETERIORATING LOG BASED ELEMENTS
I like to think that larger natural logs would last longer based on their size, protective bark, and unaltered state. The following pieces proved me wrong.
|This piece was more of a landscape feature. I am not sure what it looked like going in, but it is definitely on its way to biodegrading.|
|These stepping logs looked rough! Ethan at Natural Playgrounds let me know these were not supplied by them. His guess is that they were not hard wood. The contractor probably supplied and installed these.|
|Climber at the time of installation|
In this case study the dimensional lumber held up a lot better than the natural logs and wood pieces. This may be because of their treatment, use, or installation. It makes me wonder if this is a wide spread result and if I would find the same thing in the pacific northwest. I guess I better keep looking around!
Does anyone have photos of wood play elements 5+ years after installtion? I would love to see them.