Double Pane Window Cracked on Inside: Causes, Solutions, and Preventative Measures

A broken double pane window can be a real eyesore. Not only does it look bad, but it puts a noticeable dent in your energy bill, too. Don’t wait to fix your cracked double pane window and get your curb appeal (and energy efficiency) back on track with Glass Doctor®.

Causes of Double Pane Window Cracks

So, what exactly causes those annoying cracks in your double pane windows? Double pane windows are designed to be durable and energy-efficient, but even the best quality window glass can crack. Once you understand what caused breaking the window panes, you can address the issues.

Thermal Stress Crack

A thermal stress crack occurs when there is a significant temperature difference between the inner and outer surfaces of a window pane, causing the glass to expand or contract unevenly. Thermal cracks can be caused by:

Uneven Sun Exposure. Extreme temperature differences, such as when one side of the window is exposed to intense sunlight while the other side remains cool, can cause uneven expansion and contraction. This is especially common in climates with hot days and cool nights.

Obstructions or Window Treatments. Window coverings like heavy drapes, blinds, or obstructions like tree branches or awnings can cause uneven heating of the glass. If one section of the glass is shaded while another is exposed to direct sunlight, it can create a thermal gradient that leads to cracking.

Accidental Damage

Accidents happen and sometimes your beautiful double pane windows take the hit. Neighborhood kids playing outside can turn into flying objects hitting your window. Even tools used during home improvement projects can inadvertently hit and cause window cracks.

Structural Issues with the House

Uneven floors or sloping walls plus cracks in the walls and doors that won’t close properly all point to bigger structural problems. Cracks in your double pane windows can result from a settling house and core foundation issues.

Improper Installation

Incorrect installation, such as the glass being set too tightly within the frame, can exacerbate thermal stress. If the window lacks sufficient space for expansion and contraction, the glass is more likely to crack under pressure.

Manufacturing Problems

If the glass is not tempered correctly during the manufacturing process or if the seal between the two panes of glass is not applied correctly, moisture can sneak in and cause issues over time.

Repair and Replacement Options

While it might seem tempting to fix it yourself, a glass specialist can seal the crack within an hour or less, using the right tools and techniques – this not only saves you time but also extra money needed to correct DIY mistakes. Plus, a glass specialist will know when a double pane window can be repaired vs when replacement is the right option.

Window Glass Repair

You can likely repair the glass if you’re dealing with:

Small, surface-level cracks. If the crack is minor (less than a few inches in length) and does not penetrate deeply into the glass, it may be possible to repair it using a glass repair kit. These kits typically contain a resin that can fill in small cracks or chips and prevent them from spreading further. This type of repair is mostly for cosmetic purposes and will not restore the structural integrity of the glass.

No moisture or fogging between panes. If the crack hasn’t caused the seal between the panes to break (which would allow moisture to enter), and there is no sign of condensation or fogging between the panes, a repair might suffice. However, it is generally difficult to fix cracks inside a sealed unit without compromising the insulation.

Window Glass Replacement

If the crack is more extensive or the seal between the two panes of glass is completely broken, replacing the glass within the frame might be necessary. This, which involves removing the damaged glass and replacing both window panes.

Temporary Fixes

While it's always best to address a cracked double pane window professionally as soon as possible, you may need a temporary solution to prevent further damage and keep out the elements. To tie you over until your professional double pane window service repair arrives, you can try:

Window film or clear tape. Applying window film or clear tape over the crack can help prevent drafts and reduce heat loss (plus they easily come off prior to being repaired).

Window insulation kits. Applying a plastic film (included in the kit) over the window and sealing the edges is a temporary solution while you wait on new glass to be installed.

Window board up. Waiting on new window panes to come in? To prevent wind, rain, or debris from entering your home, board up your windows with a piece of plywood.

Hire a trusted glass specialist

At GlassDoctor, our glass specialists will work with you to find the most cost-effective and efficient solution for your specific situation. The highest quality materials ensure your windows will look and perform at their best for you and your family. Plus, we stand by our Neighborly Done Right Promise®, which ensures you’ll be happy with our work.

Preventative Steps

Once your cracked double pane window has been addressed, you want to keep your windows from experiencing large temperature fluctuations with a few simple tips.

Choose Appropriate Window Treatments.

Avoid using heavy curtains or blinds that trap heat close to the glass. Opt for window treatments that allow airflow between the glass and the room to maintain a more consistent temperature.

Install Exterior Shading Devices.

Use awnings, exterior blinds, or shades to reduce direct sunlight exposure on windows, especially on the south and west-facing sides of your home.

Apply Protective Film.

Consider applying a heat-reflective or protective film to help distribute heat more evenly across the glass surface, reducing the risk of thermal stress.

Glass Doctor Double Pane Window Repair Services Near You

A broken double pane window can be a real headache. Whether it’s a minor crack or a full glass replacement, Glass Doctor® has the experience and tools to get the job done right the first time.

Call (833) 974-0209 or schedule an appointment with Glass Doctor today!

This article is intended for general guidance only and is not applicable to every situation. You are responsible for determining the proper course of action for your property and situation. Glass Doctor is not responsible for any damages that occur as a result of advice and/or guidance derived from its blog content.