Do You Have to Replace a Failed Window Seal?

If the failed seal is the only problem with the window, then probably not. The energy-efficiency loss of the window cannot be recovered, but the effect on your power bill is almost negligible. Many homes in our Houston area still have the original single-pane windows that were the only option a few decades ago. If energy efficiency is a top priority for your home, you would be better served to go after bigger issues like air leakage, missing insulation, leaking ducts, or outdated HVAC equipment.

If the window is still letting in natural light and keeping out wind and rain, then the failed seal can be considered a cosmetic issue that should be prioritized against that stained piece of furniture you’ve been wanting to replace, or that scratch on the flooring. Is the window located in a prominent location of the home, or an upstairs bedroom with the blinds always drawn?

What is a failed window seal?

Modern, double-pane, insulated windows have two or three panes of glass permanently sandwich together with a small space in between each pane. When the window is put together, that small space is vacuumed free of air, then filled with an inert gas, usually Argon. When the seal between two panes of glass fails, air gets in that space. Air has water vapor in it and when the temperature fluctuates, you get condensation.

The condensation can look like water droplets or fogging. It can often look like vertical straight lines of streaking, but unfortunately I don’t have a technical explanation for that. All three outcomes are unsightly but not always to the same degree. Sometimes the streaking is barely noticeable and sometimes it can grab your eye right when you walk in the room. Sometimes the condensation is a few drops in the corner of the window and sometimes the window can be completely covered in fog.

This window was moderately fogged across the entire upper sash.

Can you fix it?

There is no fix that does not involve special equipment and skills. Repair companies will offer to fix it by drilling a small hole in the glass, removing the moisture and spraying in a defogging compound. The reviews on this method are mixed. The window might look drastically better immediately after the process is complete, but the root cause of the problem is not actually fixed. The condensation is likely to come back.

The other solution that does not involve replacing the whole window frame is replacing the glass. The double or triple-pane glass portion can be made by either window manufacturers or glass companies. According to The Spruce, this is a very difficult DIY project, so I wouldn’t recommend trying. With this method, you’ll avoid the construction headache of an entire new window, but the cost savings may not be significant compared to a window. This option can be just as much of a headache as a full window replacement.

This window only had faint streaking that was above eye level.

The Choice is Yours

Home inspection reports can have a lot of “recommend replacement” language, but that’s not always the right recommendation. Sometimes it’s important to point out when something is in a non-new condition, but the decision to act belongs to our clients. We want to Empower Houston Homeowners with the right information in the proper context.

Keep in mind that choosing not to fix the window doesn’t mean that it won’t come up in the next inspection when you’re ready to sell the home. This should be another factor in the replacement decision. Being a homeowner is an amazing journey, but it comes with the responsibility of handling these decisions. No home is perfect, so which fixes will give you the most satisfaction per dollar spent while also keeping up the value of your home over the long term?