Providence St. Mary Medical Center Greens Up with First Green Roof in Walla Walla, Wash.

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Tremco and Xero Flor America Announce Hospital's New 10,000-Square-Foot Green Roof

Providence St. Mary Medical Center Green Roof: Tremco Roofing Sedum Mat System, Components from Xero Flor America (XFA)

The green roof system was selected for its immediate visual impact, ease of installation, and low maintenance

Tremco Roofing and Building Maintenance and Xero Flor America (XFA), LLC announced the completion of a green roof at Providence St. Mary Medical Center in Walla Walla, Wash. The Tremco Roofing Sedum Mat System, with components supplied by Xero Flor, was installed on a 10,000-square-foot section over the Operating Suites on the Medical Center’s new 16,000-square-foot structural roof.

“Providence St. Mary Medical Center needed to replace this roof and researched the benefits of adding a vegetated roof. This roof replacement approach doubled the life of the new roof membrane and provided other benefits as well,” said Larry Baer, CHFM, CHSP, CHC, director of facilities, Providence St. Mary Medical Center. “Air temperature reduction in the summer months, sustainable management of stormwater, and an enhanced patient experience all contributed to our decision to install a green roof.”

“The green roof will help the hospital meet its sustainability goals by conserving energy,” said Elizabeth Hart, sustainable roofing specialist, Tremco Roofing and Building Maintenance. “Moderating temperatures on the roof and lowering the temperature of the air drawn into the rooftop HVAC units decreases energy use and utility costs.”

In selecting a green roof system for the project, St. Mary and its architect, Mahlum Architects, Portland, Ore., considered immediate visual impact, ease of installation and low maintenance. The Family Birthing Center and the west side of the Intensive Care Unit look out on the green roof. Thus, an instant green roof featuring extensive vegetative coverage with mature, full-grown plants for immediate beauty was a priority. In consideration of patient privacy concerns, a green roof that could be installed quickly and require minimal maintenance was also preferable. To reduce any potential for disrupting patient care, Enviroscapes Northwest, Inc., Portland, Ore., the green roof installer for the project, worked only in limited, designated hours.

“We utilize Xero Flor pre-vegetated mat technology because it has a 40-year track record of successful applications on green roofs worldwide,” said Hart. “Their vegetated mats are the only ones Cradle to Cradle (C2C) Certified for environmental sustainability.”

“The pre-vegetative mats are grown for a full 9-12 months on independent, local farms, so the plants are mature and adapted to the regional climates where they are installed. Using local horticultural suppliers also supports local economies, reduces the costs of shipping, and decreases the carbon footprint,” said Clayton Rugh, Ph.D., general manager and technical director, Xero Flor America (XFA). “And all the components for green roof projects in the U.S.A. are 100 percent manufactured in the U.S.”

About Providence St. Mary Medical Center

Providence St. Mary Medical Center, a 142-bed regional hospital located in Walla Walla, Wash. is the fourth largest employer in Walla Walla County. The Providence Medical Group is the largest group of primary care providers and specialists in the area. St. Mary is part of Providence Health & Services, a not-for-profit Catholic health care ministry committed to providing for the needs of the communities it serves – especially for those who are poor and vulnerable. In 2012, Providence affiliated with Swedish Health Service. With this affiliation, the combined scope of services includes 32 hospitals, 400 physician clinics, senior services, supportive housing and many other health and educational services. The combined health systems employ more than 64,000 people across five states – Alaska, California, Montana, Oregon and Washington – with its system office located in Renton, Wash. For more information, visit

About Xero Flor America (XFA)

Founded in 2002 and headquartered in Durham, N.C., Xero Flor America (XFA) stands at the forefront of the North American green roof industry. XFA is the official and exclusive distributor in the U.S. for the Xero Flor Green Roof System. Regionally grown on local, independent farms and 100 percent American made, the Xero Flor system utilizes advanced, lightweight, pre-vegetated mat technology. Engineered in Germany and refined over more than 40 years of ongoing R&D, Xero Flor has been proven successful and sustainable in tens of thousands of installations flourishing worldwide and covering hundreds of millions of square feet. No green roof system in the U.S. offers more validation based on independent scientific research than Xero Flor (

About Tremco Roofing and Building Maintenance

Headquartered in Beachwood, Ohio, Tremco Roofing and Building Maintenance helps manage building life cycles for customers in education, healthcare, government, manufacturing and many other industries. Tremco Roofing and Building Maintenance is a division of Tremco Incorporated, which has been in business since 1928 and is part of the RPM Building Solutions Group, an international leader in the construction, maintenance and repair markets. Tremco Roofing works closely with Tremco Incorporated subsidiary WTI, which provides general contracting and roofing services. Both Tremco Roofing and Building Maintenance and WTI are ISO 9001:2000 certified. For more information, call toll free at 800-562-2728 or visit


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