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By Gayle Lynn Falkenthal, APR

November 1, 2008 - A roof may seem like just a roof to you. But to Jim Mumford of Good Earth Plant Company, a roof is one big pot for plants. His imagination and vision have made him San Diego’s “green roof guru.” Mumford will share his expertise on green roofs in an upcoming seminar, "Introduction to Green Roof Design and Construction" at Cuyamaca College on November 8, 2008.

The half day workshop is presented in partnership with Cuyamaca College as part of its Greener Future and Renewable Energy Seminars. Mumford will be joined by architect Robert Thiele, AIA, LEED AP and roofer Ulf Waldmann of Mission Valley Roofing. Thiele has worked with both James Hubbell and artist Cristo. Waldmann is an experienced green roofer dating back to working with his father’s roofing firm in Germany 20 years ago. “I feel very fortunate to have Robert and Ulf as part of our green roof team,” said Mumford. “They have been invaluable to our ongoing success.”

The session will familiarize participants with existing green roof technology, design and construction, and discuss the significant social, economic and environmental returns on investment from installing green roofs in San Diego County. Benefits include reduced energy costs, filtering and lessening storm water runoff, extended roof life, habitat restoration and fire retardation.

Hours of the seminar are 9:30 a.m. to 12 noon and lunch is included. The class will take place at Cuyamaca College in Room F607 5510. The cost is just $20. To register, call Cuyamaca College at 619-660-4350.

Green (or living) roofs are an engineered, lightweight roofing system that supports plants.  Green roof technology is popular in northern Europe and Japan, and used in some North American cities including New York, Chicago, Toronto, and Portland.  But modern green roof technology is not well known in most of the United States.

Green roofs offer a number of benefits both to the environment and to the businesses and residents that install them.  Green roofs can:

  • Prevent water pollution by reducing the amount of storm water entering sewer systems, slowing it down and filtering it.
  • Lower energy use and energy costs for businesses and residences by insulating buildings and keeping them cooler in summer, warmer in winter
  • Lower ambient air temperatures, combating the urban heat island effect.
  • Clean the air and add oxygen, thanks to the natural properties of photosynthesis by plants and the reduction of airborne particulates
  • Mitigate the loss of environment adding biodiversity
  • Mitigates fire danger due to fire resistant roofing materials
  • Provide noise reduction
  • Extend the lifespan of the roof by two to three times

Good Earth Plants is contributing to the development of a plant palette specific to arid climates such as San Diego. Mumford focuses on drought tolerant succulents that will tolerate the harsh conditions found on roof tops in San Diego County, which has inhibited their widespread use here. Mumford is also experimenting with green walls, and recently planted a vegetable wall.

Why is Mumford so high on green roofs? After 30 years working with plants in pots as an interior landscaper, it was a natural extension of his expertise. “I wanted to show the relationship between potted plants and a green roof. A roof is really just one big pot,” said Mumford. “I hope this course will get people thinking and encourage more green roofs in San Diego County.”

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