Reinforced Transoms

Double door units are a common doorway for either a front or patio entryway. The addition of a transom is common, but the weight on the transom from the structure above may cause the transom to sag in the middle adding stress to the door unit, making the door difficult to operate. Reinforced transoms are the standard offering for composite double door frames.

A piece of 5/4 Clear Pine sits on top of the head jamb as a reinforcement and the transom sill sits on top of this reinforcement. The glass is stopped in with a specialized “L Bracket” composite stop. To cover and protect the exposed pine edges, a piece of 1/4” x 4” composite mill casing is cut into two pieces and placed over the wood. This method encapsulates the pine reinforcement.

Example of a reinforced 5-1/4″ transom unit.

The glass used to create a reinforced transom is 1″ shorter in height to maintain the same transom unit dimension as all other transoms. Due to this, single doors also have the option of having a reinforced transom. In some homes, the front door is in view of another door unit. If one transom has 12″ glass and another 11″, it may not look aesthetically pleasing. If ordering multiple doors units that will be in view of one another, this is something to consider.


Updated on May 15, 2021

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