Is Glass Resistant to Fire Damage

As traditional glass isn’t resistant to fire damage, it is crucial to understand the temperature you can expect your home’s glass windows and doors to begin breaking.  Structural fires can reach temperatures as high as 1,100° F, or 593° C. Ordinary glass can shatter at 250°F. It only takes minutes for a house fire to reach that temperature. 

Broken glass missing from the frames does not definitively denote structural damage. However, be cautious when returning to your home. If you are concerned about the structural integrity, have a professional engineer check your house before reentering. If you purchase a home damaged by fire, check out Is It Safe to Purchase a Home That Sustained Fire Damage. You can learn more about what to look for before completing the sale.

Traditional glass is what home and business window panes are made from. Some windows are double-paned with an insulating glass between the panes. While that insulation does help to keep extreme temperatures outside from affecting the temperatures inside, it doesn't help insulate against the intense heat from a fire. 

On the other hand, fire-rated glass is designed to be a barrier between flames and everything else. It helps to compartmentalize the dangerous flames and smoke away from you. In an office building, for example, fire-rated glass can allow workers to exit safely if the fire is behind the panes. 

It's also heavily tested to determine the rating. Tests include lighting the test structure on fire and allowing the temperature to get to 1,000° F on the glass surface. The glass is finally doused by a two-man fire hose. This technique enables the laboratory to determine how the panes withstand the thermal water shock from drastically differing temperatures and impact pressure from the fire hose. Based on the length of time the glass and frame remained intact, the window or door is given a rating from 20 minutes to three hours.

Two types of glass are tested for fire resistance: E-class and El-class. Both types have ratings from 20 to 120 minutes. However, each is slightly different in its design.

According to archdaily.com, E-class glass is known for its integrity at stopping fires from spreading beyond the glass. It also helps prevent smoke and potential toxins from leaving the burning area. However, it doesn’t stop heat from filtering through to the panes. The temperature in adjoining rooms can quickly rise, making it dangerous for those inside who have not had the opportunity to escape.

Still, if you have E-class glass installed, it is better than traditional window treatments where there is little to no protection at all. To ensure that you and your family are protected, the E-class glass you choose should have a fire rating of at least F120.

El-Class fire-resistant glass is a little more expensive when compared to E-class glass. As with the E-Class glass, El-Class glass is fire tested to maintain its integrity. Each pane comes with an integrity rating ranging from 30 to 120 minutes. It also provides much-needed insulation to prevent heat from escaping the burning area.

The added thickness, which accommodates an anti-thermal shield, makes it more difficult for heat to pass through. If a passerby were to lean on an El-Class pane with flames behind it, they would not get injured.

Your specific area will have building code regulations that will state whether or not fire-resistant glass is necessary. However, most homes do not need this feature. Fire-resistant glass is designed to help give occupants time to escape before a fire spreads. Suppose your home is close to another structure. In that case, you may consider installing fire-resistant glass in windows on that side.

According to Glassonweb.com, it is suggested that you have multiple fire prevention methods in place for the safety of the occupants. The use of sprinklers in conjunction with fire-resistant glass will help stop the blaze and keep it contained in a single area. However, some areas do not require a sprinkler system if fire-rated glass is in place.

If you have sprinklers and traditional windows, remember that thermal shock is a significant problem. The sudden difference in the temperature between the heat of the fire and the cool water can make the glass shatter prematurely. The fire will no longer be contained, making it more difficult for you to escape.

Traditional glass does not handle the high temperatures of a fire well. In fact, it will break relatively quickly if your home is on fire and cannot withstand the pressure from a fire hose. Fire-resistant glass, however, is better suited to protect against fire spreading throughout a space. Once you know your options and understand when to use this type of glass, you can better protect your family.