Welded Bar Grating

Another option is in using bar grating for flooring, which allows light from above the mezzanine to shine through to the floor below. This also allows the HVAC of the room to work still as designed.
This is a great option if you build a mezzanine that covers the majority of a room or space below. This is commonly used flooring in the food service industry where the floor may have to be washed down from time to time.
It is the strongest and most versatile type of open grid deck available. It allows maximum transfer of heat, sound, and ventilation between levels. Steel bar grating also Eliminate the need for a lower level sprinkler system or additional lighting. The 82% open grid area allows light penetration and excellent air flow.