1.1 本指南提供了与设计可持续低坡度屋顶系统相关的指导和注意事项，包括外露膜屋顶、覆盖植被（绿色）覆盖系统的膜、有碴屋顶和受保护的膜屋顶组件。可持续屋顶系统将环境影响降至最低，节约能源，并最大限度地延长使用寿命。 1.2 屋顶系统的主要目的是防风雨建筑物的顶面。本指南旨在实施可持续屋顶系统。 1.3 本指南承认，设计师无法控制的许多因素会影响屋顶系统的寿命。设计师可以依赖行业文献( X1.1 )以及屋顶系统的个人经验，以估计设计寿命。 1.4 本指南的前提是关注可能影响屋顶系统使用寿命的环境和其他因素。通过考虑这些因素，并在屋顶系统设计中纳入缓解这些因素及其对屋顶系统潜在不利影响的某些功能，预计屋顶系统的使用寿命将更长。 1.5 本指南包括ASTM屋顶和防水委员会D08管辖下的屋顶系统中使用的材料。尚未确定本指南对其他系统和材料的适用性。 1.6 本标准并非旨在解决与其使用相关的所有安全问题（如有）。本标准的用户有责任在使用前制定适当的安全和健康实践，并确定监管限制的适用性。 ====意义和用途====== 5.1 本指南旨在帮助用户识别和定义天气、气候和建筑用途等因素对屋顶系统的要求，因为许多屋顶具有可量化或不可量化的环境或人道主义效益的次要特征，如替代能源发电、植被或用作开放空间。 需要意识到屋顶作为这些次要功能的平台的使用，以及它们对屋顶的额外要求，以指定耐用和可持续的屋顶。 5.2 本指南的用户有责任根据此处列出的考虑因素确定实施可持续屋顶系统的适当规定要求。 5.3 规范和地方法令规定了屋顶系统的最低要求。本指南中的任何内容均不得解释为缩短或减少规范和地方条例的要求。其他实体，如建筑保险公司和系统制造商，可能对屋顶系统有要求。 5.4 屋顶系统的可持续性取决于现场和使用情况。对于某个场地或应用而言，认为可持续的屋顶系统在不同的应用中可能不可持续。对于给定的场地和应用，也可能有多个屋顶系统达到最佳可持续性水平。 5.5 本文讨论了屋顶上的植被（绿色）系统和屋顶发电系统，因为它们经常放置在屋顶上，以减少建筑的整体环境影响。这些特征通常不会影响屋顶的耐久性或寿命。如果屋顶设计中未考虑这些特征的影响，则这些特征可能会对屋顶系统性能不利，并削弱屋顶履行其保护建筑物的主要功能的能力。 5.6 屋顶系统的设计超出本指南的范围；然而，本文概述了对其潜在影响的考虑。

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. ====== 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 potential impacts is outlined herein.