For the past few weeks, I’ve been explaining how to fix a broken window pane in your home. But what if you have double pane windows? The process is the same? Well, more or less, except for a couple of variations. So let’s go over the single pane repair process and I’ll point out the differences from dual pane windows.
When we start talking about double pane windows, one of the first things that comes to mind is vinyl window frames instead of aluminum ones. When it comes to double pane windows, they can have aluminum or vinyl frames, depending on the year the house was built. Double-pane glass became popular in the 1980s, but vinyl frames didn’t really become popular until the 1990s. So if your house is less than 10 years old, you probably have vinyl-framed windows. . In any case, I will discuss the differences. Suppose you have a sliding window with an aluminum frame and double pane glass. The procedure for removing the opening frame and sash glass is the same as for single-pane windows.
The differences are, firstly, that the glass enters the frame about twice as much as the single pane window. Single pane window glass is set 1/4″ into the surrounding rubber. Double pane is typically set 1/2″ into the rubber. So if both pieces of glass have broken, you will need to order a new IGU (Insulating Glass Unit) from your local glass shop. They are going to want to know the width, height, total thickness, and possibly the thickness of the individual glass. The best way to get the dimensions is to measure the width and height from rubber band to rubber band, writing down those numbers. Then remove the panel from the opening and lay it flat on a table like we did with the single pane window. Remove the screws from opposite corners and pull out 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 you measured earlier (1/2″ for two sides = 1″). Next, measure the overall thickness of the unit by removing the rubber from the edge of the glass.
Usually this dimension is 1/2″, but not always. There is a metal spacer that divides the two glass panels. Make a note of the color so you can request the same color on the new IGU. It will be silver or bronze If you want to get the same spacer size, you must provide the glass shop with the thickness of each piece of glass in the IGU If the unit above has 1/8″ glass on both sides, and the total 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 mind matching the thickness of the spacer, you can order the glass thicker than 1/8″ 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 GUI has been broken? Many times the outer panel will break, but the inner panel is fine. You can order a whole new GUI like we just did or, if you’re the adventurous type, you can order just the single glass panel that broke 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 removed the window panel on the table with the surrounding frame, you will see a black rubber-like substance around the edge where the spacer is applied. This is a butyl sealant and broken crystals need to be separated from this butyl. The best way to do this is to take a utility knife with a fresh blade and break the butyl where it meets the broken glass. Next, take a new hacksaw blade and push it into the area where you separated 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.
Once this is done, place rags over the good glass piece to catch any debris and scrape the surface of the spacer that will be in contact with the new glass. Use a spatula. Then remove the rags and debris. When you’re ready to put in the new glass, clean the inside of the good glass that you didn’t remove. Remember, once you install the new glass, any residue or finger marks on the interior will be permanently sealed. So clean it up real good and check it from all angles. Do the same for the side of the new glass that will go inside the GUI. Then apply a thin bead of clear silicone around the entire perimeter of the spacer. Place your new glass on the spacer and press down with your fingers to adhere the glass to the silicone all the way around. Then approach from the side and run the silicone around the side where the glass and spacer meet. Cover the window opening with something for 24 hours. You don’t want to touch the GUI for 24 hours. The silicone needs to cure. After 24 hours, you can assemble the unit and install it back in the opening.
There are a couple of things that can go wrong. The first is leaving marks on the inside of the glass. Once he seals the glass, he can’t clean what’s between the panes. The other thing involves condensation between the panels. If you have even the slightest break in the silicone seal around the glass, you’ll likely start to see moisture build up as soon as the nights get colder and the days get warmer. You’ll need to decide if you’re confident enough in their ability to do the job well, or if it’s better to pay the extra money to have them do it for you. Just because you pay someone to do it doesn’t mean you won’t have the same problems. The difference is that they have to guarantee their GUI for a minimum of 1 year. I have received many units over the years that had marks between the glass. The beauty of this is that the manufacturer can’t argue with it, because no one else could have done it except them.
Well, what if the window frames are vinyl instead of aluminum? Well, the main difference is that vinyl window glass no longer has the rubber gasket around the edge. It does not remove the screws from opposite corners and separates the frame from the glass. What they do is put silicone or double-sided tape on the edge of the frame where the glass rests. That’s what holds the glass in the frame, then they apply a snap stop to all four sides of the glass. So you need to remove the bumpers first, then flip the panel over and break the seal holding the glass to the frame with a utility knife. Wear gloves during this procedure. If only one side of the GUI is broken, don’t even think about repairing just one side. You’ll never get that GUI out of the frame without breaking the other piece of glass in the process. But, on the plus side, you can remove the stops without taking out the panel if it’s a slider. You can then measure the dimensions of the glass and order the new GUI. That way you eliminate any need to temporarily cover your window. The same is true for the stationary part of a slider or image window. Before installing the new GUI, be sure to clean the edge that had the tape or silicone and apply silicone or tape. Either one will work.
You will find that replacing a GUI on an aluminum framed window is much easier than a vinyl window. But in any case, you can do it yourself and save a few bucks.