Light steel joist plasterboard ceiling轻钢龙骨石膏板天花吊顶1.1 Construction sequence施工顺序Positioning and paying off---install hoist members---install main keel—install minor keel—accept hidden works---install plasterboard---apply emulsion定位放线——吊杆构架安装——主龙骨安装——副龙骨安装——隐蔽工程验收——石膏板安装——批嵌刷乳胶漆1.2 Construction tool施工机具Electric hammer, electric keel shear, gun drill, profile cutter, electric welder电锤、电动龙骨剪、手枪电钻、型材切割机、电焊机等。
1.3 Construction conditions 作业条件a) Materials shall conform to quality standards through acceptance.材料经验收符合质量标准。
b) Construction interfaces meet with requirements. Power, water and ventilation pipelines have been completed by and large, as well as the lighting position and vents.施工界面符合衔接要求。
水电管线及通风管道安装基本完成，灯位、通风口等基本到位。
c) installation of power, water and ventilation pipelines, and hidden ceiling foundation work have been completed and accepted, commissioning and thermal insulation have been completed and the surface plates are applied before ending水电管线及通风管道安装、吊顶基层隐蔽工程验收合格，调试、保温作业完成，经验收合格，平顶罩面板才能封顶收头。
1.4 Operation elements操作技术要点a) Mark lines弹线Mark the ceiling elevation line along the wall according to the floor elevation benchmark line and along the horizontal line, mark the position lines for the keels and extend it to the foundation layer of the top slab.根据楼层标高基准线沿墙四周弹顶棚标高水平线，并沿水平线，在墙上划好龙骨分档位置线，并把龙骨位置线引到顶层楼板基层上.b) Expansion joints and suspender埋膨胀螺栓、安装吊杆：Mark properly the main keel position lines and decide the suspender space and position along the main keel position lines. Control drilling depth with retainers to ensure the hole diameter matches with the expansion bolts. The anchor force for M8 expansion bolts shall not be less than 4.31KN and the suspender space of the main keels shall not be wider than 1.2m, and the length at cantilever end of the main keel shall not be larger than 0.3m. 弹（绷）好主龙位置线，按设计要求和国家规范规定，沿主龙骨位置线确定吊杆间距、定位，埋膨胀螺栓固定主龙骨吊杆。
钻孔深度用限位器控制，孔径应与膨胀螺栓规格匹配。
M8膨胀螺栓锚固力不小于4.31KN，主龙骨吊杆间距不大于1.2m，主龙骨悬臂端长度不大于0.3m。
c) Install keel suspender安装龙骨吊杆Decide the suspender length according to the marked line and fasten them by direct expansion bolts or welding before applying secondary rust-resistant paint. In case of moisture, apply lubricating oil to screws and nuts after installing the keels.按弹线尺寸确定吊杆长度，采用直接膨胀螺栓式或焊接式固定，刷二度防锈漆。
如在潮湿环境则在龙骨安装调整好后，螺丝、螺帽上涂润滑油。
d) Install the main keels安装主龙骨*) Assemble main keel according to the bracket line and adjust elevation and straightness according to the drawn line, with the central arch of 20-25mm.按分档线位置组装主龙骨，按拉线调整标高和平直，中心起拱度约为20-25mm。
*) additional brackets shall be required to fasten the suspender in case large air ducts to ensure 1-1.2m space遇大口径风管应另安装支架固定吊杆，以保证间距1-1.2m。
*) To enhance the ceiling foundation stability and resistance to deformation, 40 x40 galvanized angle steel or channel steel shall be used for the large-area ceiling foundation to add reverse support and horizontal cross bracing.为增强吊顶基层整体稳定性和抗变形能力，在大面积天棚基层应用40*40镀锌角钢或槽钢增设反撑和水平剪刀撑。
*) Manhole shall be set according to drawings. The main keel frame at the manhole shall be suspended independently and fastened laterally with the main keel system to prevent horizontal displacement. The manhole system shall use the products approvedby the designers.检修洞口应按图设置, 洞口加装主龙骨框应独立悬吊，并在横向与主龙骨系统固定，防止水平方向晃动移位。
检修口系统应使用设计师认同产品。
e) Install center keels安装中龙骨Center keel space shall not be greater than 400 x400mm based on the plasterboard modulus and installation position, which shall be fastened with the wall along the side keels.中龙骨间距按石膏板模数和安装部位不大于400*400mm，按分档线吊挂，通过沿边龙骨与墙体固接。
f) Facing plasterboard石膏板覆面*) Installation ofδ12 plasterboard ceiling starts from the ceiling center along the center keel direction and extends toward two sides with stagger joints.吊顶δ12石膏板(硅钙板)覆面安装应从顶棚中间顺中龙骨方向开始，向两侧伸延分行，交错接缝。
*) the overlaying plasterboard (calcium silicon board) is fastened by galvanizedself-tapping screws and positioned by bracket, which shall be fastened in the center first and then towards the four sides.罩面石膏板(硅钙板)使用镀锌自攻螺丝固定，施工时应使用托架定位，先固定中间然后按序向板四周延续。
*) Screw space shall be within 150-170mm and the nut shall penetrate into the board about 0.5-1.0mm but shall not penetrate the paper. The screw is 10-15mm to the edge. Apply two tiers of rust-proof paint at screw end.螺钉间距控制在150~170mm之间，螺丝帽沉入板内0.5~1.0mm但不应穿破纸面，钉距板边10~15mm。
并在螺尾涂防锈漆二度。
*) The overlapped right angle position of the ceiling is stress concentrated, which shall be cut properly in advance and use trapezoid-shaped overlaying to avoid edge joint at the right angle positions of the overlapped ceiling.花迭级直角处应力集中，应预先裁好、使用曲尺形板罩面，避免天花迭级直角处拼缝。