- Jan 28, 2019-

1/4" wire glass and ceramic glass are the most

common types of glazing used in fire rated

doors. The hourly rating of the door dictates

the number and maximum size of the vision

lights used in the door. Table 2 shows the

limitations of size, area and number of vision

lights in a door. Vision lights are not allowed in

3-hour rated fire doors, unless allowed by the

local authority having jurisdiction. The vision

light kit or window frame must be approved for

use in a fire rated door.