Do Window Films Cause Seal Failure?

Do Window Films Cause Seal Failure?

window film seal failures

For decades now, customers have been asking us if our window films are safe for their dual pane windows. More than likely their inquiry is prompted because of the window installer mentioning to them that window films cause dual pane windows to develop seal failures. Or, they called the window manufacturer asking about applying window films and their response was, “it will void your warranty.”

Recently we discussed what actually causes a dual pane window to develop a seal failure . It’s very important to examine the causes of seal failure to fully understand the potential impacts of applying window film to your dual pane windows.

Its also extremely important to understand all dual pane windows WILL eventually develop a seal failure and have some kind of fogging occur. If you don’t believe me, here is Joe Hayden a engineer of the top window manufacturers Pella, stating:

“Eventually, fogging will develop between the panes of any insulating glass product. Given enough time, the seals between the panes will break down and allow moisture to enter. The desiccant material will attract and hold as much moisture as it is capable of, but will eventually become saturated. When that happens, fogging will occur. Exactly how long this will take is dependent on the actual environmental conditions, the sealing and desiccant materials used, the design of the insulating glass, the overall design of the window, and a host of other factors too numerous to mention here. But simply stated, nothing lasts forever.” – Joe Hayden, Pella Engineer

When we discuss seal failures with customers, the most misunderstood fact is that their dual pane windows will eventually fail, as all dual pane windows will at some point. As the saying goes, ”Nothing last forever.” Often times, if your dual pane windows are 10 or more years old, you may already have seal failures, you just can’t see them yet because it takes time for the foggy appearance to develop.

So, how did window film get a bad rap for being the cause of dual pane fogginess? Well, there is two reasons really. Let me explain.

Reason one is that often times homeowners have invested a good amount of money in their windows and when their gateway to the outside world becomes obscured by nasty looking fog, they are naturally upset. Fortunately, most top window manufacturers offer some kind of dual pane seal failure warranty. In the event a seal failure develops within a certain amount of time, they will replace the window unit at no charge or a minimal charge.

So how does window film come to play in this scenario? Well obviously replacing windows is not free for the window manufacturer; they have the cost of the window plus the labor. So you can be assured they will do their best to examine the situation thoroughly and look for exemptions and stipulations to their warranty. Who can blame them? They’re a for-profit business and they need to identify the cause of the issue and determine the proper liability. Other factors can be at play also, such as improper installation. This is where the window installers comes into the picture. The window installer does not want to be at fault or on the hook for replacing windows either.

However, there is not one single piece of evidence suggesting that when the correct window films are applied to dual pane windows they will increase the risk of seal failure. In fact its the opposite .

So what is the solution? I have seen countless scenarios where a customer has a seal failure with window film applied to it and the window manufacturer will not honor their warranty. Often, our window films are applied on the west, south and east facing windows; not typically on the north. So I will walk into a home and notice the north side also has seal failures. How do we explain this? The window film on the southern windows didn’t cause the northern windows to develop a seal failure, did they? Nope! It goes back to the fact that all dual pane windows will eventually develop a seal failure. With or without window film, it has been tested that window seal failures occur at of rate of about 1% or 1 out of a 100 windows.

Reason number two for why some blame window film for seal failures is, improper window film selection. There are some window films or window tints that are not compatible with dual pane window units, specifically automotive window tints and various other applied window film products. Its not uncommon for someone one who does automotive tinting to tackle a few “flat glass” jobs. What frequently happens is these “professionals” do not want to invest in anymore inventory, so they spin any automotive film they have and fling it onto any flat glass that comes their way. What happens? Well, automotive films are designed a little differently; they are meant to be dark and non-reflective, which is a bad combo for dual pane windows with lots of sun exposure. This combinations puts tons of stress on the glass and the window seals, causing premature seal failures and/or a glass fracture. Bad news indeed!

Good News

Now, for the good news! Window film manufacturers have figured out how to eliminate this entire headache. If you have dual pane windows that do not have any existing signs of seal failures and you have window film professionally installed by someone like a authorized 3M window film dealer, you will automatically receive a 3 year (40 months) seal failure warranty.  Window film manufacturers like 3M will even take it a step further, you have a lifetime warranty such as the one offered by Milgard, 3M will match that exact warranty word for word for a tiny additional fee. Talk about peace of mind.

Do you think there would be a window film industry like it is today if, whenever window film was applied to a window, it would cause damaging issues to the window? Its a very small percentage of windows that ever develop issues with or without window film and the window film manufacturers such as 3M, Vista and Huper Optik are willing to offer you peace of mind because of these facts.

Hopefully this shines some light on the issues at hand and we understand it can be confusing when you hear conflicting information. So if you’re reading this now, because somebody told you window film caused seal failures, please share this link with them so we put an end to the myth!