To obtain a copy of a specific publication, users should contact the publication's publisher directly.
Abstract
Typical roof design focuses on removing water from roofs as efficiently and quickly as possible. While this benefits the roof and building, it often adversely affects the surrounding ecology and stormwater collection and treatment system. Growing building density has also reduced areas of natural soils that absorb rain with the resultant increase in the volume of water flowing into municipal stormwater systems. This contributes to flooding and the uncontrolled discharge of untreated waste into rivers, streams, etc. the link between green roofs and water control is the subject of this paper, which looks at available systems and assemblies and those that are recommended, water retention rates of green roofs and the quality of the runoff, local regulations, Leadership in Energy and Environmental Design (LEED) credits for green roofs, and design criteria. A green roof should have a high-quality waterproofing/roofing system, because of the expense of removing the plant growth components to make repairs to the protection layers of the roof. This also raises warranty issues. The amount of stormwater runoff helps determine the depths of growing media, and whether the water retention system is extensive (40% of stormwater) or intensive (up to 90% of stormwater). Plants should be suitable for the local climate and to the type of green roofing system selected. The building owner must also be committed to ongoing maintenance (e.g., weeding, pruning, etc.). A specialist also needs to be consulted with regards to local conditions and regulations and how they affect green roofs. To summarize, green roofs can provide water management features that address local authority concerns and regulations relating to stormwater management. Green roofs offer other benefits that can help to offset the added cost. Regardless of the reasons a green roof is being considered, it will be a custom design for the particular building and the design will be based on greatly varying ranges of performance.
Typical roof design focuses on removing water from roofs as efficiently and quickly as possible. While this benefits the roof and building, it often adversely affects the surrounding ecology and stormwater collection and treatment system. Growing building density has also reduced areas of natural soils that absorb rain with the resultant increase in the volume of water flowing into municipal stormwater systems. This contributes to flooding and the uncontrolled discharge of untreated waste into rivers, streams, etc. the link between green roofs and water control is the subject of this paper, which looks at available systems and assemblies and those that are recommended, water retention rates of green roofs and the quality of the runoff, local regulations, Leadership in Energy and Environmental Design (LEED) credits for green roofs, and design criteria. A green roof should have a high-quality waterproofing/roofing system, because of the expense of removing the plant growth components to make repairs to the protection layers of the roof. This also raises warranty issues. The amount of stormwater runoff helps determine the depths of growing media, and whether the water retention system is extensive (40% of stormwater) or intensive (up to 90% of stormwater). Plants should be suitable for the local climate and to the type of green roofing system selected. The building owner must also be committed to ongoing maintenance (e.g., weeding, pruning, etc.). A specialist also needs to be consulted with regards to local conditions and regulations and how they affect green roofs. To summarize, green roofs can provide water management features that address local authority concerns and regulations relating to stormwater management. Green roofs offer other benefits that can help to offset the added cost. Regardless of the reasons a green roof is being considered, it will be a custom design for the particular building and the design will be based on greatly varying ranges of performance.
Date
4/2009
4/2009
Author(s)
Jeffrey Brouillard; Edward Stewart
Jeffrey Brouillard; Edward Stewart
Page(s)
49-57
49-57
Keyword(s)
stormwater; green roofing; water control;
stormwater; green roofing; water control;