Grand Rapids Replaces Tree Grates with Permeable Paving Material

Grand Rapids, Mich., is completing the replacement of 750 old iron tree grates with Porous Pave XL. Porous Pave is a pour-in-place surfacing material that consists of recycled rubber, stone aggregate and a binder.

The first phase of the project was completed in September 2014 before the annual ArtPrize event. The city had Porous Pave tree surrounds installed to replace 250 cracked and broken grates that presented the most serious tripping hazard in the three square miles of downtown. An additional 500 grates will be replaced by July 2015.

“Porous Pave allows rainwater and air to get down to the tree roots,” said Mark DeClercq, P.E., city engineer. “With its high rubber content and textured surface, Porous Pave is slip resistant and safer when wet than traditional metal tree grates.”

“Porous Pave is ADA-compliant,” said Dave Ouwinga, president and CEO of Porous Pave, Inc. “In addition to making Porous Pave surfaces slip-resistant, the recycled rubber gives it flexibility, so it withstands freeze-thaw cycles without heaving, cracking or breaking.”

Porous Pave XL is made from 50% recycled rubber chips and 50% stone aggregate with a moisture-cured urethane binding agent. It infiltrates storm,water on site, decreases the volume and slows the velocity of runoff flowing into storm drains and storm sewers, improves water quality by reducing erosion and filtering out pollutants, and recharges groundwater. The material’s porosity, permeability and slip resistance make it ideal for tree surrounds.

Named "America's Greenest City" by Fast Company magazine, Grand Rapids has received worldwide recognition for its sustainability efforts. The city’s multi-year sustainability plan sets more than 200 specific targets in sustainability, energy efficiency, conservation and renewable energy. 

Source: Porous Pave Inc.