ASTM D7851-17
(Guide)Standard Guide for Design of Sustainable, Low-Slope Roofing Systems
Standard Guide for Design of Sustainable, Low-Slope Roofing Systems
SIGNIFICANCE AND USE
5.1 This guide is intended to help the user identify and define demands made upon the roofing system by factors such as weather, climate, and building use, in light of the fact that many roofs are specified with secondary features that have quantifiable or non-quantifiable environmental or humanitarian benefit such as alternative energy generation, vegetation, or use as open space. Awareness of the roof’s use as a platform for these secondary functions, as well as the additional demands they make upon the roof, is needed to specify a durable and sustainable roof.
5.2 It is the responsibility of the user of this guide to determine the appropriate prescriptive requirements for implementation of the sustainable roofing system based on considerations listed herein.
5.3 Codes and local ordinances set minimum requirements for roofing systems. Nothing in this guide should be construed to abridge or lessen requirements of codes and local ordinances. Other entities, such as building insurers and system manufacturers, may have requirements for the roofing system.
5.4 Sustainability of a roofing system is site and use specific. A roofing system considered sustainable for a certain site or application may not be sustainable in a different application. There may also be more than one roofing system that achieves an optimal level of sustainability for a given site and application.
5.5 Above-roof vegetative (green) systems and rooftop energy generation systems are discussed herein because they are frequently placed on roofs to reduce the building’s overall environmental impact. These features do not generally contribute to the durability or longevity of the roof. These features may be detrimental to roof system performance and impair the roof’s ability to perform its primary function of protecting the building if their impact is not accounted for in the roof design.
5.6 Design of above-roof systems is beyond the scope of this guide; however, consideration of their p...
SCOPE
1.1 This guide provides guidance and considerations related to designing sustainable low-sloped roofing systems, including exposed membrane roofs, membranes covered with vegetative (green) overburden systems, ballasted roofs, and protected membrane roofing assemblies. A sustainable roofing system minimizes environmental impact, conserves energy, and has maximized service life.
1.2 The primary purpose of a roofing system is to weatherproof the building’s top surface. Implementing a sustainable roofing system is the intent of this guide.
1.3 This guide acknowledges that many factors outside the designer’s control affect the longevity of a roofing system. The designer may rely on industry literature (X1.1) and personal experience with roofing systems to estimate the design life.
1.4 The premise of this guide is to focus attention on environmental and other factors that may affect the roofing system over its service life. By considering these factors and incorporating into the roofing system design certain features that mitigate these factors and their potential adverse effects on the roofing system, the roofing system would be expected to have a longer service life.
1.5 This guide includes materials used in roofing systems under jurisdiction of ASTM Committee D08 on Roofing and Waterproofing. The applicability of this guide to other systems and materials has not been determined.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
General Information
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Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D7851 − 17
Standard Guide for
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Design of Sustainable, Low-Slope Roofing Systems
This standard is issued under the fixed designation D7851; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
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2.1 ASTM Standards:
1.1 This guide provides guidance and considerations related
D1079 Terminology Relating to Roofing and Waterproofing
to designing sustainable low-sloped roofing systems, including
exposed membrane roofs, membranes covered with vegetative
3. Terminology
(green) overburden systems, ballasted roofs, and protected
3.1 General—Terms used in this guide are defined in
membrane roofing assemblies. A sustainable roofing system
Terminology D1079, except as defined below.
minimizes environmental impact, conserves energy, and has
maximized service life.
3.2 Definitions:
3.2.1 design life—the planned period of time during which
1.2 The primary purpose of a roofing system is to weather-
the roofing system is expected by its designer to reliably
proof the building’s top surface. Implementing a sustainable
perform its required functions, with minimal unplanned inter-
roofing system is the intent of this guide.
vention.
1.3 This guide acknowledges that many factors outside the
3.2.2 durability—the ability of the roofing system to per-
designer’s control affect the longevity of a roofing system. The
form its required functions over a period of time within the
designer may rely on industry literature (X1.1) and personal
environment for which it is designed and exposed.
experience with roofing systems to estimate the design life.
3.2.3 service life—the period of time after installation dur-
1.4 The premise of this guide is to focus attention on
ing which a roofing system performs its required function(s)
environmental and other factors that may affect the roofing
with minimal unplanned intervention.
system over its service life. By considering these factors and
4. Summary of Guide
incorporating into the roofing system design certain features
NOTE 1—The sustainable roofing system design process consists of the
that mitigate these factors and their potential adverse effects on
following, sequential steps:
the roofing system, the roofing system would be expected to
4.1 Identification of Roofing System Demands, Functional
have a longer service life.
Expectations, and Site Constraints—The designer should de-
1.5 This guide includes materials used in roofing systems
termine factors, loads, and stresses that the roofing system must
under jurisdiction of ASTM Committee D08 on Roofing and
withstand as well as the impacts the roofing system may have
Waterproofing. The applicability of this guide to other systems
on the environment the building interacts with. These factors
and materials has not been determined.
apply limiting constraints for system and material selection and
the associated installation process. There are also options for
1.6 This standard does not purport to address all of the
sustainable strategies and site and use constraints that will
safety concerns, if any, associated with its use. It is the
define the feasibility of sustainable strategies (for example,
responsibility of the user of this standard to establish appro-
availability of sunlight for photovoltaic arrays).
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
4.2 Determination of In-Service Performance Criteria and
Functional Expectations—The designer determines perfor-
mance criteria and functional expectations of the roofing
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This guide is under the jurisdiction of ASTM Committee D08 on Roofing and
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Waterproofing and is the direct responsibility of Subcommittee D08.24 on Sustain- For referenced ASTM standards, visit the ASTM website, www.astm.org, or
ability. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Current edition approved Feb. 1, 2017. Published February 2017. DOI: 10.1520/ Standards volume information, refer to the standard’s Document Summary page on
D7851-17. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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D7851 − 17
system in response to the in-service roofing system demands, 6. Procedure
NOTE 2—The design process includes the following tasks, shared with
functional options, and site constraints. Performance criteria
prudent design of
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