For centuries the divided lite patterns in a window or a door have been inherent to the design of the architecture. Early on the making of large pieces of glass was very difficult so multiple divided lites was the only way to make a larger window or door. Over the years glass sizes have dramatically increased, yet the desire for divisions in the glass still remains strong in many architectural designs.

There are two primary ways to divide the glass today. There is still a true division of the glass using multiple individual lites or there is a simulated division that can be used to create a similar appearance with better energy values. There are advantages with both approaches and each have different merits.


TDL (True Divided Lite)

For many situations, the true dividing of the glass is the best way to create a pattern in the window or door. It has been the traditional approach for years and has advantages.

Structurally, the divided lite muntins and bars help to strengthen the sash. They span the stiles and rails and keep parts firmly connected. In steel products this also helps to stabilize the narrow profiles of extra tall or extra wide sash.

When using true divisions each piece of glass is individual for each lite and this reduces the square footage of the glass and therefore allows for thinner glass and ultimately less weight. This plays a role with extra large swing and sliding doors.

In steel products the lock box generally is notched into the glass. The true divided lites can help hide spacer bars and enhance the visual appearance.

Beyond these advantages, the extra material included in a muntin or bar does increase the thermal conduction and the result is a higher U-factor result when calculating the unit value.


SDL (Simulated Divided Lite)

The simulated divided lite is created using one overall piece of glass in the sash and then a surface grid is welded into the sash on the exterior. The interior beauty ring is also welded up with a matching grid pattern. When fully installed this gives a similar appearance as the true divided pattern.

The advantages of the simulated pattern starts with improved NFRC U-factor values. Because the glass is not broken multiple times, there is an improvement in thermal resistance and the unit values have better performance values.

The simulated pattern will also allow for a narrower width of the muntins and bars. Where 1 3/8" wide is the typical true divided width, with the use of the simulated divided lites, widths of 7/8", 1" and 1 1/8" can be achieved.

Variations of TDL and SDL Profiles
Energy Values
Thermal Design
glazing
Finish
Hardware
Automation
Attachment
Divided Lites
Mullions & Corners
Multi-Point
Escutcheons
Hinges & Finials
Screens
Door Sills
Safety