drywall drop ceiling grid
-
...
Next, determine the location of the main runners. You will need to install hanger wires to support the main runners. Hanger wires should be spaced no more than 4 feet apart, and they should be attached to the ceiling joists. Use a power drill to make holes in the joists and insert the wires securely, ensuring they are taut and hanging down to the level of the desired grid height.
...
1. Accessibility Requirements According to the Americans with Disabilities Act (ADA), all access panels must be accessible and easy to operate. This means that the location of access panels should be determined with consideration for mobility challenges. Additionally, panels should be operable with one hand and not require tight grasping, pinching, or twisting of the wrist.
ceiling access panel code requirements

...