[RP TownTalk] Rubber sidewalks

Mon Jul 17 21:47:19 UTC 2006

These rubber sidewalks are interesting, and might be good around trees. 

However, they are experimental . The claim that they last 3 times 
longer is questionable. 

This claim only applies to sidewalks subject to tree root damage . 
Otherwise, it would appear that concrete walks last longer and are a lot cheaper. 

These rubber walks have only been installed in real world east cost test 
situations for a couple of years so any claim that it lasts 14 years or 3 times 
longer than concrete is suspect.

Using experimental materials have expenses that are often
overlooked, like training, evaluation and new maintenance procedures.
Staff time investigating and maintaining these things would be costs 
that are significant for a small town like us. As an example, they
recommend removing these rubber pavers every few years and
trimming the tree roots. That would be a new expense. 

Still it is exciting to see new technology that might help keep
sidewalks in good shape and if we have people interested in 
investigating this further, we might all benefit.

According to their web site: $15 is the average cost per square foot 
for break out and installation. In April, the District of Columbia installed 
about 4,000 square feet of rubber sidewalk, at a cost of $60,000.
[The New Rochelle install cost $20/sq foot vs $7 for concrete, see below.]

------------

For those interested, here are some comments I found on the web..

The walkways are made of ground recycled tires molded into
squares [that weigh about 20 lbs each]; .. and fit together using
fiberglass pegs. 

If crews need to get to anything beneath, they just lift the
sidewalk. For now, they are installed around trees along Rhode
Island Avenue between North Capitol and 15th streets NE.  
[ Anybody up for a short road trip to check these out? ]

Unlike concrete, which is poured and set on location, the prefab
rubber squares arrive from its California factory and are cut to
fit. Installers usually place Rubbersidewalks pavers over a bed
of crushed granite and connect the pavers using interlocking
dowels. The result: a sidewalk with a two-inch-deep footprint —
far shallower than its concrete cousins. To repair a rubber sidewalk, 
workers unlock the dowels and remove the individual paver.

"We might have a little trial and error here," said Sharif
Fattah, who lives in the area where the sidewalks are being
tested. "I wonder how you shovel a rubber sidewalk?"

"The advantage is that you can effectively drape the rubber sidewalk 
over the tree roots. When you do concrete, in order to get a smooth 
walking area, you tend to trim the roots ," says Deatrick.

"They're pleasant to walk on. They rise and fall with the trees. "

Around tree roots, the walkways are said to last about 14 years -
- nearly three times longer than concrete ones -- [I am highly
suspect of this claim].

Concrete suffocates tree roots, which then grow upward to fight
for air and water. [is this true?] The roots break the concrete, which 
trips the pedestrians, who sue the city. Rubber sidewalk panels have
quarter-inch spaces between them that let air and water through,
so tree roots grow downward like they should. [Makes me wonder
about using traditional pavers that also allow water thru and 
can also be removed and replaced].

Much of the cost of the sidewalk is shipping, because rubber is
heavy and the company, Rubbersidewalks Inc., is 2,700 miles away
in Gardena, Calif. By next year, the company and the District
hope a new plant will open in New York, slicing freight charges.
Rubbersidewalks plans to open a new factory in Lockport, N.Y., in
the fall, a move it hopes will cut costs to customers in the
eastern half of the country. Still, the cross-continental cost of
transporting the tiles amounts to only about $1.50 per square
foot, Smith estimates. [ Shipping is only about 10% of the cost ].

Saving trees may be the real cost savings.

"I haven't determined if it's cost-effective, " says Jeffrey
Coleman, New Rochelle's commissioner for public works. The city
installed a stretch of rubberized walkway to preserve one of its
older and more scenic tree-lined streets. "We wouldn't put this
in our downtown. In a downtown area, if you have to take a tree
down, it's not the end of the world."

So far, Coleman is impressed that the material hasn't cracked
after two New York winters. "It's flexible, pliable. That's one
of the nice features," he says. "I figured they would have been
beat up by a snow shovel or something."

[Some user comments found on a blog]

This is not environmental friendly. The tire wear pollution run
off into the ocean is bad enough as it is, why would anyone want
to add more synthetic materials that nature isn't accustom too?
[Others claim it is environmentally friendly since it is recycled
rubber, but there is some debate here.]

If it gets too cold though, rubber has a tendency to get brittle
(and easier to damage). Also, if there is a lot of snow or ice, I
would expect the sidewalk to give little traction to the
pedestrian as they would likely be smoother than concrete.

How do we prevent people from stealing these and posting a
thousand Instructable projects that use "free" rubber panels? I
have read the manufacturer's site, and this is never explicitly
addressed. I think, if a maintenance crew can remove them, then
there must be an easy way for anyone to remove them. This is
cool, but I fear that after the first one gets taken, they're up
for grabs...

-----------------

Info on the New Rochelle test install from the companies web site:

"I don't see this replacing all sidewalks, but it would have a
place where you are trying to keep the conflict between roots and
sidewalks to a minimum," said James Maxwell, New Rochelle's
public works commissioner.

New Rochelle is spending $8,400 for the sidewalks and installation, 
or $20 per square foot, much higher than the city's cost of $7 per 
square foot for concrete.

In New York, Spring brought warmer weather, chirping birds and a note from 
New Rochelle Commissioner, James Maxwell, reporting that Rubbersidewalks 
sailed through another rough winter with no damage or disruption.  The rest of the 
sidewalks-concrete-didn't fare so well.  [I think this is two years old now, you can 
what appears to be broken concrete in the distance].

Above picture in higher resolution at
http://www.rubbersidewalks.com/images/installations/3D684X3E/show/New%20Rochelle%20Winter%2006%203.jpg

A reprint of the New Rochelle article is on the company's web site:
http://www.rubbersidewalks.com/pdf/a0124rubbersidewa.pdfhttp://www.rubbersidewalks.com/pdf/a0124rubbersidewa.pdf

------------------------

Washington Post Article:
http://www.washingtonpost.com/wp-dyn/content/article/2006/07/01/AR2006070101087.html

CBS news article:
http://www.cbsnews.com/stories/2006/07/12/tech/main1796714.shtml

Company web site: http://www.rubbersidewalks.com 

For more details, contact Lindsay Smith at Rubbersidewalks, Inc.,
2622 West 157th St., Gardena, Calif., 90249. Call 310-515-5814 or
email rubbersidewalks at aol.com.

[end]
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