Impact-resistant sliding glass doors help keep you and your home safe during a storm. They're designed to hold together if they're hit by debris carried by high-speed winds, preventing rain and wind from entering your home.

The secret behind impact-resistant glass is polyvinyl butyral (PVB), which is very durable plastic. Impact-resistant glass consists of two panes of glass with a thin sheet of PVB between them. When an object strikes the glass, the PVB will hold all of the glass together instead of allowing it to shatter apart.

Unfortunately, impact-resistant glass is prone to delamination, especially if it's poorly made. This occurs when the PVB between the two glass panes starts to pull away from the glass. Delaminated impact-resistant glass can ruin your view from the sliding glass door, and it also reduces its ability to withstand impacts. To learn how you can tell if your sliding glass door is delaminating and what causes it, read on.

How Do You Know Your Impact-Resistant Sliding Glass Door Is Delaminating?

You'll be able to tell your sliding glass door is delaminating when bubbles or cloudy areas start appearing in the glass. They're most likely to start appearing at the edge and spread towards the center. You can tell that a cloudy area on your window is from delamination and not a stain if no amount of cleaning or polishing can make it transparent again — the problem is happening between the two panes of glass.

What Causes an Impact-Resistant Sliding Glass Door to Delaminate?

Impact-resistant glass will delaminate if the PVB is exposed to water or high humidity. Wind-blown rain that hits your sliding glass door can seep its way between the glass and the frame. From there, it can migrate between the two panes by capillary action.

Once water is between the two panes, it will begin to dissolve the adhesive that holds the PVB to the glass panes. Once the adhesive has dissolved, the PVB will pull away from the glass. Since the edges of the glass are the places where water can intrude, delamination usually first starts there.

Poor manufacturing can make impact-resistant glass more susceptible to delamination. If the manufacturer doesn't compress the two panes of glass against the PVB tightly enough, there's more room for water to seep in between the two panes.

Can You Repair Delaminated Impact-Resistant Glass?

Unfortunately, there's no way to get the two panes of glass apart in order to reattach the PVB to the glass. The only way to repair an impact-resistant sliding glass door that has started delaminating is to remove and replace the glass.

If your impact-resistant sliding glass door is showing signs of delamination, call a residential glass door replacement service in your area and have the glass replaced. In addition to being able to see out your sliding glass door perfectly again, you'll also restore its ability to withstand impacts — glass that has badly delaminated is no longer securely held together by the PVB between the two panes, and is more likely to shatter. 

For more information, contact a local company like Broadview Glass Window and Door.