The standing tubes and the transverse and longitudinal tubes shall be fastened by square couplers without sparing any lifts or omissions. The deviation on the rectangularity of the standing tubes shall be no bigger than 0.75% the height of the scaffolding body, no bigger than 60mm.
The standing tubes shall be located on the hard pressed concrete ground and the bottom of the standing tubes shall be backed with wood base plates with thickness of 50mm. It is forbidden to use any bricks as the back plates.
All the scaffolding couplers shall be pressed putlog coupler kinds with an accordance with GB 15831 requirements on the scaffolding couplers. If using the second hand couplers, there shall carry out a scrutiny to see if there is any crack or deformation. Should there be any sliding in the thread, the bolt shall be exchanged. All the pressed putlog coupler used in the high formwork supporting system shall not be damaged when the torsion force of the bolt reaches to 65N/M.
The whole body of the scaffolding shall be set with longitudinal and transverse bridging braces as well as the horizontal diagonal braces for the sake of integrity of the whole scaffolding body.