Understanding Structural Requirements of Stained Glass Windows

If you’re considering adding custom stained glass to your home, you may be wondering about the practical considerations of doing so. After all, you may associate stained glass with ancient buildings like cathedrals.

So what are stained glass window structural requirements for today’s homes and businesses?

Let’s take a look at what exactly you’ll need to add that beautiful decorative glass you’ve had your eye on.

Requirements of stained glass

Professional stained glass artists don’t only have a creative and imaginative eye for what colors and designs work best—they also understand the functional, structural requirements of their craft. A stained glass window would not be very useful if it is not installed correctly, and it could even be hazardous.

Stained glass window structures

This starts with proper panel size and reinforcing systems, which are critical elements in the structure of a traditional leaded stained glass window. A leaded stained glass window panel shouldn’t be more than 12 square feet. Any large stained glass piece comprises several panels which are divided by T-bars or via other means.

This structural system is meant to move the weight from the stained glass window’s upper panels to the panels below, which are on the window sash or frame. This prevents a situation where the upper leaded panels’ weight causes damage to the lower panels, resulting in bulging and collapsing over time.

Reinforcing bars made of steel are connected via copper wires or directly to the ends of the sash or window frame. If these reinforcing bars aren’t connected, then the structure of the window is not sound. If the windows begin to sag or bulge, this demonstrates that they’re not structurally sound. This could be a serious hazard if not addressed and corrected.

Round bar vs. flat bar systems

Traditional structural systems use round bars. More modern systems use flat steel bars which are stronger and more rigid. These are affixed directly to the lead’s solder joints. The round bar system attaches by copper wire to the stained glass panel’s solder joint.

The round bar system’s benefit is its flexibility during expansion and contraction cycles, which are a consistent feature of changes in the weather. This allows for some movement through the tie wires while the window’s flat structure remains intact.

Other structural considerations

Stained glass windows, when designed properly, will last for centuries to come. These design elements include:

  • Glazing cement between the flanges of the lead and the panels
  • Accurate design of the lead matrix
  • Proper placement of stack joints, mutin and T-bars
  • Framing systems made to withstand the elements
  • Material composition of the lead came
  • Vented exterior glazing systems that preserve the window

If you’re interested in beautiful custom stained glass for your home or business, then trust the pros at Smiths’ Stained Glass. Our team will create expertly-crafted pieces designed to your specifications and competitively priced. Our work will last for years to come, as we only use quality materials and install them the right way. Contact us right now to learn more and get started on your first project.