The stair openings, elevator openings, passage openings, and reserved openings installed in the grid structure engineering are called the "four ports" on the grid structure installation site, and they must be protected in accordance with the requirements of the regulations and warning signs should be set.

1. The handrails of stairs or ladders should be installed in time, otherwise, 1.2m high temporary guardrails should be installed along the stairs or ladders for operation and passage.
2. The elevator shaft head in the installation of the construction grid shall not be transported vertically except for elevator installation. The elevator shaft should be equipped with 1.2m high guardrail or movable door to be firm and reliable.
3. At the passageway of the grid engineering installation site, when there is high-altitude installation work on the upper part, a protective shed must be set up. The width of the shed should be greater than the entrance and exit, and the length should be set according to the height of the building. The roof is covered with wooden boards no less than 125px thick.
4. The surrounding area of the high-altitude installation of the grid, including the platform or pit, must be equipped with 1.2m high guardrails, and safety nets should be hung in accordance with regulations. Protective sheds should be erected near dormitories, offices, etc. around high-altitude installations. The roof of the protective shed shall be covered with wood boards no less than 125px thick to ensure the safety of people and buildings.
5. The enclosure and protection of the grid installation construction site shall be implemented in accordance with relevant safety and civilized construction management regulations.