From: clewis@ferret.ocunix.on.ca (Chris Lewis)
Newsgroups: misc.kids,misc.consumers.house
Subject: Re: Playground rubber mat?
Date: 3 Oct 92 17:21:43 GMT
Followup-To: misc.kids
Organization: Elegant Communications Inc., Ottawa, Canada

In article <gmJ2RB1w161w@cdthq.UUCP> gary@cdthq.UUCP (Gary Heston) writes:
>mma@bellcore.com (Mary M. Lau) writes:
>
>> I am looking for soft and durable to put under
>> my daughter's outdoor swing set.  I vaguely
>> remember someone posting a question on getting
>> the black rubber-like mats a while back but I 
>> don't recall seeing an answer.  Can someone
>> please post the information again?

>> I would be interested in other alternatives
>> (we had already eliminate using pebbles and 
>> sand).

All quotes from "Home Playgrounds", Merilyn Mohr, Camden House/Harrowsmith.

Safe fall heights:

10" masonry sand		11'2"
8" natural pea stone		11'2"
12" bark/woodchips		10'2"
2 1/2" "manufactured surface"	 8'2" (what Mary's referring to)
1 1/4" "manufactured surface"	 4'1"
packed earth			 2'9"
asphalt				   10"
concrete			    8"

>I don't know about rubber mats; that'd seem expensive if you put
>down an adequate layer, and not real durable if they were 
>relatively spongey.

>An article I read recommended a 6" layer of pine bark nuggets.
>Apparently, those resist compaction, and have a fair amount of
>resiliance, while not breaking the bank.

The word missed is "durable"...

    "In some parts of the country, organic materials like tanbark and wood
    chips are cheap and available, but although very resilient, they have
    several disadvantages.  Wood chips swell when they get wet, displacing
    the air trapped between fragments that give them their cushioning
    capacity.  Dampness leads to decay and the ground cover gradually
    compacts as it decomposes.  Organic materials harbour microorganisms
    such as fungi, insects and even small rodents.

    An occasional visiting vole may be preferable, however, to the animals
    that sand attracts...  Unwashed pit-run sand sand contains a range
    of particle sizes, and after a few rainfalls, the small grains
    roll between the large ones, settling to the consistency of hard-packed
    earth.  Even masonry sand, which is composed to relatively uniform
    particles that are not easily compacted, has to be raked regularly
    to keep the material loose and resilient.

    ...  For safety, durability and weather resistance, pea stone is the
    best overall resilient ground cover, but even it must be raked regularly
    to prevent it from compacting as dirt accumulates between the tiny
    crevices.

    ... The continual landing of small feet [under a swing] kicks the
    ground cover away from the base of slides, sliding poles and swings,
    thining it dangerously.  For these vulnerable spots, manufactured
    ground covers are ideal, though they are too expensive for large
    areas.  Water permeable and designed to withstand both the heat
    and cold of the outdoors, these resilient squares are anchored
    permanently in place.  They are especially useful under swings,
    where kids' dragging feet otherwise ruts that become mud holes
    after a rain.  Available as tiles or interlocking pavers..."

We loath "pine bark nuggets".  While they obviate some of the deterioration/
compaction characteristics of shredded bark, under a swing or slide, they'll
get scattered all over the place.  Making lawn mowing an adventure
in shrapnel avoidance.  Besides, earwigs just *love* bark nuggets.

Near us is a playground based around structures that encorporate water
pumped by hand pumps.  The majority of the ground cover is sand,
but at the base of the stainless steel water slide is a small rectangle
of "manufactured surface".  I originally thought it was a slab of wood
or even concrete with a bit of carpet on it.

I remember thinking that we'd have to rush anybody who actually fell
on it to hospital, and was going to write a letter to the city.
Then I saw a 7-8 year old girl go down the slide, and not get her
feet under herself in time...

"Oh oh" I thought, as the girl's mother let out a yell and started to
run...

From the 18" drop at the end, she fell square on her backside onto
the mat.  She bounced a good 6 *feet* horizontally onto her feet,
the only result was an one of the most shocked looks I've ever seen.
Her swimming suit weren't even dirty.  We all had a good laugh - led by the
girl herself.

But she was a bit more careful next time...

Neat stuff.  All the parents huddled around the slab and poked and
prodded it to see what it was like.

The Harrowsmith book lists several playground suppliers (all Canadian),
but doesn't indicate which ones can supply the material.  So I'm
not going to type them all in.

The book does consider pea gravel as second best for under swings.

Call a local manufacturer or retailer.  They'll be able to help
you.  Sorry I don't have better sources.
-- 
Chris Lewis; clewis@ferret.ocunix.on.ca; Phone: Canada 613 832-0541
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