Drawings should be carried out before the installation of steel joint hearing before the joint hearing of construction units should be familiar with and master design file contents, find the component mounting problems affecting the design and review with other professional engineering with inappropriate ways.
  
1 drawing Mixed

Before installation of steel structures, construction units in order to solve problems in a familiar drawing found during the technical problems and quality problems found in the drawings nipped in the bud, the parties participating in the construction drawings to conduct joint hearing.
Mixed content drawings generally include:
Qualification (a) meets the design units, drawings, whether by design unit officially signed.
(2) design units to do the design intent description and proposed process requirements, the main production unit introduces steel production process.
Have a contradiction between (3) professional drawings.
(4) between each drawing plane position, elevation, etc. are the same, mark whether the omission.
(5) the professional construction and construction procedures with or without problems.
Construction methods (6) Install the unit can meet the design requirements.

2 design changes

In the construction drawings before use, after use of design changes will occur due to the construction unit requirements, or changes in construction site conditions, or changes in national policies and regulations and other reasons caused. Design change for whatever reason, who proposed the construction unit must obtain the written consent and apply the change. There will schedule and cost impact of design changes, in strict accordance with the regulations should be implemented in order to clarify responsibilities and avoid claims event is not conducive to the construction.