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What Are Window Muntins and Mullions?

Muntins and mullions are two terms you don’t usually hear every day. They are found on your windows, and to many who are aware of them, the terms are often used interchangeably. The fact, however, is that these are two different things altogether. Renewal by Andersen® of New Jersey explains the differences between window muntins and mullions.

Window Muntins and Mullions

What Are Window Muntins?

These are vertical dividers separating glass panes inside your multipane glass window. Muntins are not only components in windows, but also serve as vertical dividers for wood panels, furniture or doors.

Centuries ago, muntins were installed to stabilize a window’s structure. They also provided assistance for large windows to help manage their weight against the outer walls. Muntins are often made of wood, but they also come in materials like steel or aluminum.

What Are Window Mullions?

These are single vertical bars separating the two sides of your window. Before, they were added to provide support to the window glazing. Nowadays, they are either completely decorative pieces or serve as a separation between a stationary and movable set of windows so you can open and close them with ease. Mullions also add depth by resisting wind loads during severe weather.

The Differences Between Muntins and Mullions

The difference between muntins and mullions comes down to what they separate. While muntins separate panes of glass, mullions divide windows or door frames. Additionally, muntins separate panes of glass in a multipane glass composition. On the other hand, mullions are single vertical bars for two-pane assemblies.

To learn more about your replacement windows, turn to the design consultants of Renewal by Andersen of New Jersey. Call us now at (800) 577-7744 or fill out our contact form for a consultation. We serve clients in Toms River and Jackson, NJ.


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