阿里A14。9-2019规定了有关永久安装的金属或木材、各种类型的阁楼楼梯的安全设计、施工、测试、维护、安装和使用的规则，这些楼梯设计用于进入阁楼等高层。本标准仅涵盖额定负荷为250、300和350磅的家用单元，或额定负荷为500磅的商用单元。本标准不适用于任何其他ANSI A14标准中涵盖的阁楼楼梯，也不适用于天花板高度超过12英尺的阁楼楼梯。本标准还规定了阁楼楼梯安装说明和标签的规则和最低要求，以促进正常使用条件下的安全。

ALI A14.9-2019 prescribes rules concerning the safe design, construction, testing, care, installation and use of permanently installed metal or wood, disappearing attic stairways of various types designed to be used for access to upper levels such as attics. Household units with duty ratings of 250, 300 and 350 lbs., or commercial units with a rating of 500 lbs. are the only units covered in this standard. This standard is not intended to apply to any attic stairway covered in any other ANSI A14 standards, or disappearing attic stairways intended for use with ceiling heights in excess of 12 feet. This standard also prescribes rules and minimum requirements for installation instructions and labeling of disappearing attic stairways in order to promote safety under normal conditions of usage.