For the past few weeks, I have been explaining how to repair a broken window pane in your home. But, what if you have dual pane windows? Is the process the same? Well, pretty much, except for a couple of variations. So, let’s review the single pane repair process, and I will point out the differences regarding dual pane windows. When we start talking about dual pane windows, one of the first things that comes to mind is vinyl window frames instead of aluminum. When dealing with dual pane windows, you can have either aluminum or vinyl frames, depending on the year the house was built. Dual pane glass got popular in the 1980’s, but vinyl frames didn’t really catch on until the 1990’s. So, if your house is less than 10 years old, chances are you have vinyl framed windows. In either case, I will discuss the differences. Let’s say you have a sliding aluminum frame window with dual pane glass. The procedure for removing the frame from the opening and the glass from the sash is the same as with the single pane windows.You may find more information at double pane window repair.
The differences are, first, the glass goes into the frame about twice as far as the single pane window. The single pane window glass went 1/4″ into the surrounding rubber. The dual pane usually goes 1/2″ into the rubber. So, if both pieces of glass have been broken, you are going to have to order a new IGU (Insulated Glass Unit) from the local glass shop. They are going to want to know the width, height, overall thickness, and possibly the individual glass thickness. The best way to get the dimensions is to measure the width and height from rubber to rubber, write those numbers down. Then, remove the panel from the opening and place it on a table like we did with the single pane window. Remove the screws from opposite corners and pull of the frame. You will be able to see how far the glass goes into the surrounding rubber. If it’s 1/2″, then you want to add 1″ to the width and height that you measured previously (1/2″ times two sides= 1″). Then, measure the overall thickness of the unit by removing the rubber from the glass edge.
Typically, this dimension is 1/2″, but not always. There is a metal spacer that divides the two panes of glass. Make a note of the color so you can request the same color in the new IGU. It’s either going to be silver or bronze. If you want to get the same size spacer you need to give the glass shop the thickness of each piece of glass in the IGU. If the old unit has 1/8″ glass on both sides, and the overall thickness of the unit is 1/2″, then they will use a 1/4″ spacer. If the glass is 3/32″ on both sides, they will use a 5/16″ spacer. If you don’t care about matching the spacer thickness, you can request the thicker 1/8″ glass, and they will automatically use a 1/4″ spacer.
When you get the new IGU home, the installation is the same as the single pane window. Now, what if only one side of the IGU has been broken? Many times the outer pane will break, but the inside pane is fine. You can order a whole new IGU Like we just did, or, if you’re the adventurous type, you can order only the single pane of glass that was broken and replace it. I’m going to explain how to do it, then i’m going to tell you the things that can go wrong. After you have the window pane on the table with the surrounding frame removed, you will see a black rubber type substance around the edge where the spacer is applied. This is a butyl sealant, and you have to separate the broken glass from this butyl. The best way to do it is to take a utility knife with a new blade and break through the butyl where it meets the broken glass. Then, take a new hacksaw blade, and push it into the area where you sparated the butyl from the glass. You don’t want the hacksaw blade to be attached to a hacksaw. Using your hand, saw back and forth as you work your way around the edge of the glass. This should allow you to remove the glass.