Glass Breakage After Installation
HOW CAN GLASS BREAK AFTER IT IS ALREADY INSTALLED INTO A WINDOW FRAME?
Glass is a static product and will not break without some form of impact, pressure, pinch point, or unequal energy transfer. This pressure or energy can be caused suddenly, or over a period of time by either a direct contact area or indirect transfer.
Window Frames in walls
Direct: Something actually contacting or impacting the glass and indirect being without actual direct physical glass contact.
Indirect: Energy transferring can occur when someone slams a nearby door, or an impact to a common wall area and the energy is transferred into the glass through the wall or frame.
Environment: Extreme temperature exposure, differences, ranges or direct sun causing expansion, contraction, or thermal shock.
Other common causes of installed or existing glass breakage:
- Unequal pressure can be caused by framing abnormalities such as being out of true, plumb, square or level.
- Having a bow, belly, twist anywhere in the frame.
- Improper or lack of utilization of glazing tape at any point of either the frame or removable stops.
- Stops set too tight in frame, or stops were factory preset for thinner glass.
- Debris or a high point on sill that glass is set on.
- Screw fasteners over tightened causing a pressure point or "spreading" the stop channel and resulting "eggshell" or stress crack run.
- Glass not undersized enough to fit into window frame. (Standard is typically 1/8" gap all around perimeter, 1/4" total undersize)
- Not utilizing bottom sill shims or spacers. Or not using enough shims equally spaced for the total width of glass.
Vision Frames in Swinging Doors
Glass occurring in vision frames installed into doors the possibility of the door being "slammed" or closed too hard causing the glass to break with out any signs of direct impact.
- Glazing bead or the framing is possibly too tight and set for thinner glass.
- Fasteners over tightened causing an "eggshell" or stress crack run.
- Door is warped or has a bend, bow, belly or twist.
- Glass not undersized enough to fit into vision frame, or into door cut out rough opening size.
* If any of these conditions occurs and exists and are not diagnosed and corrected, then chances are very high that a yet another piece of replacement glass will also break again.
PREVENTION ADVICE TO HELP REDUCE GLASS BREAKAGE RISK:
- Carefully and accurately measure frame or cut out and properly figure undercut/undersize.
- Carefully check frame for true, plumb, square and level (Very Important)
- Make sure glazing bead and frame are set for the actual thickness of glass + room for glazing tape both sides
- Carefully check frame or door for any bow, twist, belly, warp or high points
- Use proper glazing tape on frame and all stops and frame that have any contact with the glass
- Use equally spaced setting blocks and shims on bottom sill, and use spacers.
- For vision frames make sure they are fabricated with space for the actual glass thickness + glazing tape
- Only hand tighten screws for final snug fit, but never over-tighten or use a power tools to tighten.
- Order Impact Resistant safety glass if installing into a door vision frame or in a side-lite.
- Order Impact Resistant Safety Glass if installing in a window frame within 25" of any door opening.
- Order Impact Resistant safety glass if installing in any potentially hazardous location.
- Always wear proper protective gloves and eye protection whenever handling glass.