Paint and Coatings Industry News

Main News Page

Green-Roof Group, Roofing-Industry Association Issue Test Standard on Root-Barrier Performance

Tuesday, April 19, 2011

More items for Building Envelope

Green Roofs for Healthy Cities (GRHC) and the Single Ply Roofing Industry (SPRI) announced the publication of a standard test method for the evaluation of a roof material’s resistance to root or rhizome penetration.

The standard—VR-1, Procedure for Investigating Resistance to Root Penetration on Vegetative (Green) Roofs—was developed to evaluate the performance of a roofing material functioning as a root-protection or waterproofing layer.

The test is based on the FLL (Forschungsgesellschaft Landschaftsentwicklung Landschaftsbau) “Procedure for Investigating Resistance to Root Penetration at Green Roof Sites,” and has been approved by the American National Standards Institute (ANSI), GRHC said.

“As the use of sustainable and green construction practices continues to increase, so does the use of vegetative roofing systems,” said Mike Ennis, technical director of SPRI. “To support this growing trend, SPRI and GRHC are developing standard procedures and guides for use by design professionals, system manufacturers and contractors.”

GRHC and SPRI have worked in partnership to develop a number of standards in support of the development of the industry. ANSI/SPRI VF-1, The External Fire Design Standard for Vegetative Roofs, was completed in 2010, and the ANSI/SPRI RP-14, Wind Design Standard for Vegetative Roof Systems, was completed early this year. Other standards under development include performance standards for the multiple functions of growing media.

The standards are available as free downloads from Green Roofs for Healthy Cities at GRHC Green Roof Standards or from the SPRI website at SPRI Publications.

“This new root repellant test standard will help North American manufacturers provide their green roof clients with a faster method that gives third-party assurance that the waterproofing will be protected from unwanted root growth,” said Steven W. Peck, founder and president of GRHC. “Experienced Green Roof Professionals (GRPs) have all of the tools, products and techniques required to not only protect against leaks, but to also ensure that the waterproofing lifespan under green roofs is doubled, if not tripled, for significant owner savings.”

Comment from Paul Graham, (4/20/2011, 8:12 AM)

A properly designed and installed Green Roof should last 75 to 100 years. No damage from outside trades, no UV damage, no hail damage. We do presentations to Architects, and everyone is really excited until they see the cost, which starts around $18 and goes up to $45 per SF. A plaza deck with planter boxes might be a better fit, and more useable. You know- Outdoor kitchen, BBQ, picnic table, fire pit- the important things.