序言这是CSA A123的第三版。3、沥青饱和有机屋面油毡。它取代了1998年出版的第二版和1979年出版的第一版沥青或焦油饱和有机屋顶毡。它是CSA沥青屋面材料系列标准（CSA A123.1至A123.5）之一。CSA A123系列标准以SI（公制）单位编写，符合CAN/CSA-Z234。1.1范围1。1. 本标准涵盖了与符合CSA A123的屋面沥青一起使用的带有穿孔的沥青饱和有机屋面油毡。4.在建造无穿孔的组合式屋面薄膜时，将其用作沥青瓦、木瓦、瓦、瓷砖和其他屋顶覆盖物下方的垫层。1.2 本标准涉及以下类型的屋面毡: （a） 类型1——用于建造组合式屋顶膜的穿孔屋顶毡。它通常被称为15号毛毡穿孔。 （b） 2类-普通、无穿孔的屋面毛毡，用作沥青瓦、木瓦、木瓦、瓷砖和其他陡坡屋顶覆盖物下方的垫层。它通常被称为15号普通毛毡。 （c） 类型3——普通、无穿孔的屋面毛毡，用作沥青瓦、木瓦、木瓦、瓷砖和其他陡坡屋顶覆盖物下方的垫层。它通常被称为30号普通毛毡。1.3 以SI（公制）单位给出的值是标准值。括号中给出的值仅供参考。1.4 在CSA标准中，“应”用于表示要求，即用户有义务满足的条款，以符合标准； “应该”用于表示建议或建议但不需要的建议；“可”用于表示一种选择或在标准范围内允许的选择；“can”用来表示可能性或能力。 注释随附条款不包括要求或替代要求；随附条款的注释的目的是将解释性或信息性材料与文本分开。 表和图的注释被视为表或图的一部分，可以作为要求编写。附件被指定为规范性（强制性）或信息性（非强制性）以定义其应用。

PrefaceThis is the third edition of CSA A123.3, Asphalt saturated organic roofing felt. It supersedes the second edition, published in 1998, and the first edition, Asphalt or Tar Saturated Organic Roofing Felt, published in 1979. It is one of a series of CSA Standards on bituminous roofing materials (CSA A123.1 to A123.5). The CSA A123 series of Standards are written in SI (metric) units, which are in conformance with CAN/CSA-Z234.1.1 Scope1.1 This Standard covers asphalt saturated organic roofing felt, with perforations, to be used with roofing asphalts conforming to CSA A123.4 in the construction of built-up roofing membranes, without perforations, applied as an underlayment beneath asphalt shingles, woods shakes and shingles, tiles, and other roof coverings.1.2 The following types of roofing felts are addressed by this Standard: (a) Type 1 - perforated roofing felt that is used in the construction of built-up roofing membranes. It is commonly referred to as No. 15 Felt Perforated. (b) Type 2 - plain, non-perforated roofing felt used as an underlayment beneath asphalt shingles, wood shakes and shingles, tiles, and other steep slope roof coverings. It is commonly referred to as No. 15 Plain Felt. (c) Type 3 - plain, non-perforated roofing felt used as an underlayment beneath asphalt shingles, wood shakes and shingles, tiles, and other steep slope roof coverings. It is commonly referred to as No. 30 Plain Felt.1.3 The values given in SI (metric) units are the standard. The values given in parentheses are for information only.1.4 In CSA Standards, "shall" is used to express a requirement, i.e., a provision that the user is obliged to satisfy in order to comply with the standard; "should" is used to express a recommendation or that which is advised but not required; "may" is used to express an option or that which is permissible within the limits of the standard; and "can" is used to express possibility or capability. Notes accompanying clauses do not include requirements or alternative requirements; the purpose of a note accompanying a clause is to separate from the text explanatory or informative material. Notes to tables and figures are considered part of the table or figure and may be written as requirements. Annexes are designated normative (mandatory) or informative (non-mandatory) to define their application.