Grantee Research Project Results
Final Report: Developing a Turnkey Vegetative, Substrate and Container Assembly for use with Residential and Commercial Extensive Roofs in New England and Southeast Canada
EPA Grant Number: SU832481Title: Developing a Turnkey Vegetative, Substrate and Container Assembly for use with Residential and Commercial Extensive Roofs in New England and Southeast Canada
Investigators: Swan, Chris
Institution: Tufts University
EPA Project Officer: Page, Angela
Phase: I
Project Period: September 30, 2005 through May 30, 2006
Project Amount: $9,792
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2005) RFA Text | Recipients Lists
Research Category: P3 Challenge Area - Chemical Safety , Pollution Prevention/Sustainable Development , P3 Awards , Sustainable and Healthy Communities
Objective:
The green roof industry has begun to develop regional applications specific to the Western, Middle and Southeast U.S., but few, if any, for the Northeast. In fact, EP has just begun this process in Boston, MA. The mission for our students is to expand on the EPA or other efforts in our region; they will not only help identify regional species appropriate for green roofs but test them in conjunction with proprietary recycled aggregate and forest products in shallow, ultralight HDPE containers. If successful, students will help pioneer a substantial environmentally and regionally appropriate assembly system for future applications over a vast geographic region.
A team of Tufts students in the Civil and Environmental Engineering (CEE) department are designing a ‘turnkey’ green roof system that can be use to convert conventional roofs into green roofs. The system is adaptable so that it can function on a wide variety of roofs. The students plan to design and implement a pilot study of a green roof, using the ‘turnkey’ system, on the Tisch Library, located in the center of the Medford/Somerville, MA campus of Tufts University. The pilot study’s goals are 1) to evaluate how well a turnkey system will work and 2) initiate Phase II of the project where different plant species and substrate combinations will be evaluated for optimal growth conditions as well as provide other benefits such as heat island reduction, storm water management, and insulation characteristics. The work done in Phase I of the project was performed by four CEE seniors (Kimberley Bowman, John Dulac, Derek Fehrer, and Lael Nelson) and three CEE sophomores (James Hughes, Jared Rodriguez, and Jayson Uppal).
The objective of the green roof to be designed and implemented at Tufts is to have it provide as many of these benefits, while at the same time enhance Tufts’ image as a cutting-edge, environmentally-conscious university. Thus, the major scopes of work for Phase I of the project were 1) the development of a novel turnkey assembly system, 2) development of a green roof design for Tisch Library, the university’s largest library, and 3) developing and implementing a pilot study of tray assemblies on the roof of Tisch Library.
Summary/Accomplishments (Outputs/Outcomes):
For the turnkey assembly system, the team researched green roofs to see what methods could be adapted for a final design. Different possible assembly methods were evaluated and a tray system was adopted for design and implementation. The trays can be put directly onto a roof provided the roof is sufficiently waterproof and drainage from the bottom of the tray is not deterred.
The site for project implementation of a green roof is the Tisch Library roof at Tufts University. The roof system of Tisch Library has two levels, an upper deck and lower deck. The lower roof deck is well suited for a green roof system because it is flat, large (approximately 1.25 acres in area) and is already covered with a waterproof membrane. The initial design for a green roof on Tisch Library was developed in consultation with Tufts University’s Facilities Department. Discussion centered on the type of green roof system to install and how to implement the installation. These discussions lead to the following design characteristics:
- The roof should be an extensive green roof.
- A tray assembly system is preferred, particularly because the trays are an easy way to rearrange the roof.
Based on discussions with the Facilities Department, the team developed an initial roof layout for Tisch Library’s new green roof, with the goal to create a park like, walkable space. The size of the roof leads to a 5-phase plan for implementation. Each phase is meant to appear as a stand-alone project and continue to incorporate principles of design.
At the writing of this report, the pilot study was just beginning. The initial purpose of the pilot study was to evaluate plant survival, but in Phase II, the pilot study area will become the “default laboratory” for evaluating plant species and engineering characteristics. Currently, the pilot study consists of testing four different aggregates in the Licht tray assembly. The aggregates consist of a traditional, expanded clay/shale lightweight aggregate; synthetic lightweight aggregate (SLA) which is composed of a mixture of recycled plastics and coal fly ash; the third aggregate is pelletized HDPE; and the last aggregate is a recycled asphalt shingle aggregate (RASA) consisting of granulated roofing shingles. Each aggregate is mixed with approximately 20% forest mulch to provide nutrients and organic matter for the plants. With twelve plant types and four aggregates, 48 trays will be created and monitored. Monitoring will be visual in seeing how well the plants grow in each aggregate and well as physical measurements of temperature (above and below the trays), precipitation, infiltration, and other parameters.
Conclusions:
A team of Tufts students are designing a ‘turnkey’ green roof system that can be use to convert conventional roofs into green roofs. The system is adaptable so that it can function on a wide variety of roofs. The students plan to design and implement a pilot study of a green roof, using the ‘turnkey’ system, on the Tisch Library, located in the center of Tufts University’s campus. A pilot study has been initiated with goals of 1) evaluating how well a turnkey system will work and 2) initiating Phase II of the project where different plant species and substrate combinations will be evaluated for optimal growth conditions as well as provide other benefits such as heat island reduction, storm water management, and insulation characteristics.
Supplemental Keywords:
Storm water, contaminants, evaportranspiration, CAM, media, aggregate, Region 1, RFA, Scientific Discipline, INTERNATIONAL COOPERATION, Sustainable Industry/Business, POLLUTION PREVENTION, Sustainable Environment, Energy, Technology for Sustainable Environment, Engineering, Environmental Engineering, energy conservation, cleaner production, alternative building technology, ecological design, environmental conscious construction, green building design, green roof, alternative materials, energy efficiency, pollution prevention design, architectureThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.