Glass Fireplace Door Spontaneously Cracking

This situation arises when the fireplace has been repaired by an inexperienced technician.

Glass fireplace door spontaneously cracking. An internal flaw or damage to the glass. Spontaneous breakage is a relatively well known in the glass industry but somewhat rare phenomenon associated with tempered safety glass. With an increase in spontaneous glass breakage incidents the glazing industry is looking at new ways to make assemblies safer. For example if it s cold outside and a heat vent is located very close to the glass door pane itself the sudden heating of the glass could cause the pane to expand quickly resulting in a crack that leads to shattering.

Internal defects within the glass such as nickel sulfide inclusions. The cracks will be long running cracks as opposed to the small cubed appearance of shattered tempered glass. Most often shattering will occur as a result of fluctuations in temperature. Meshulam described tempered glass as being like a tightly wound spring that can reach a spontaneous breaking point for one of two reasons.

Thermal stress cracks in windows are easy to identify because they start perpendicular to the glass edge. Binding of the glass in the frame causing stresses to develop as the glass expands and contracts due to thermal changes or deflects due to wind. The number one reason glass doors break is because of some form of damage to the glass around the edges of that door meshulam said. Those pressure layers eventually cause the glass to just shatter.

One rather common cause of tempered spontaneous breakage is known as a nickel sulfide inclusion. Largest selection of fireplace glass doors on the internet for masonry fireplace or factory built fireboxes. It s easy to identify a stress crack if you can see the edge of your glass added howard. Thermal stresses in the glass.

A thrown toy an elbow hitting the surface and other mishaps can break the glass as well. Inadequate glass thickness to resist wind load. If the fireplace glass is not tempered glass the heat of the fireplace will cause thermal expansion and the glass will crack. The number two reason would be through inclusions microscopic imperfections that grow into a larger crack internally to the pressure layers.

Images courtesy ppg industries. Outdoor fire experts fire bowls fire pits fireplaces. A tiny almost invisible chip or crack can occur if a door is nicked by a misaligned screw or is bumped along the delicate outer edges.