Adding a lite, or piece of glass, to a door is often wanted and the same can be said for commercial doors. There are three measurements when it comes to a commercial lite. The order size is the opening that is found in the door. Into this opening, the entire lite frame system is installed. The glass does not extend from edge to edge of the door but is instead 1/2″ shorter on each side. Therefore the glass size is 1″ smaller than the order size. Finally, the lite frame extends past the edge of the glass 1/2″. The visible lite size, or exposed glass size, is 1″ smaller than the glass size, or 2″ smaller than the order size.

Lite Types
There are three kinds of lite inserts which can be installed into a hollow metal or commercial flush wood door.
Clear Tempered Glass
Clear Tempered Glass will hold no fire rating. Therefore, the size of the glass does not matter in relation to a fire rating. Tempered glass is a type of safety glass with increased strength compared with normal glass. If the glass is broken, it will crumble into small granular chunks instead of splintering into jagged shards.

Pyran F Glass (Clear Ceramic Safety Glass)
Pyran F Glass is able to hold a fire rating. The fire rating of the door though relies on the size of the glass that is visible. A door lite that is 100 square inches or less will not affect the door fire rating. Pyran F glass is a heavy duty 7 mil durable safety film with neutral colortation

Safe-Wire Fire Glass
Safe-Wire Fire Glass is able to hold a fire rating. The fire rating of the door though relies on the size of the glass that is visible. A door lite that is 100 square inches or less will not affect the door fire rating. It has a 3/4″ x 3/4″ diamond pattern that maintains integrity when fractured or subjected to a hose stream.

Lite Sizes
Adding a lite over 100 square inches to a fire-rated door though will decrease it’s rating by 50%. The overall unit can only be rated to the lowest rating possible. For example, a 22” x 28” safe-wire lite is 616 square inches and will maintain a 45 minute fire rating. If installed into a 90 minute door, the door and lite together will have an overall rating of 45 minutes. If that same 45 minute rated lite is installed into a 20 minute rated door, the door and lite together will maintain an overall 20 minute rating.
Standard Layout Options

4″ x 25″ Exposed Glass
6/8 Door: A = 12″
7/0 Door: A = 16″

10″ x 10″ Exposed Glass
6/8 Door: A = 12″
7/0 Door: A = 16″
C Always Equal

22″ x 28″ Exposed Glass
6/8 Door: B = 6-1/2″
7/0 Door: B = 8-1/2″
C Always Equal

22″ x 58″ Exposed Glass
6/8 Door: B = 6-1/2″
7/0 Door: B = 8-1/2″
C Always Equal
Glass Order Size | Exposed Glass Size | Safe-Wire Glass | Pyran F Glass | Clear-Tempered Glass | ||
---|---|---|---|---|---|---|
90 Min Door | 20 Min Door | 90 Min Door | 20 Min Door | Non-Rated | ||
6″ x 27″ | 4″ x 25″ | Up to 90 mins. | Up to 20 mins. | Up to 90 mins. | Up to 20 mins. | Non-Rated |
7″ x 22″ | 5″ x 20″ | Up to 90 mins. | Up to 20 mins. | Up to 90 mins. | Up to 20 mins. | Non-Rated |
12″ x 12″ | 10″ x 10″ | Up to 90 mins. | Up to 20 mins. | Up to 90 mins. | Up to 20 mins. | Non-Rated |
24″ x 30″ | 22″ x 28″ | Up to 45 mins. | Up to 20 mins. | Special Order | Special Order | Non-Rated |
24″ x 60″ | 22″ x 58″ | N/A | N/A | N/A | N/A | Non-Rated |
Other options and styles may be available for special order though. Please contact Reeb’s Commercial Quoting or Customer Service Department for more information.