Replacing broken glass in a vinyl sliding glass door

Last week, I explained how to replace broken glass in an aluminum sliding door. The process is different if your sliding door frame is vinyl. So, let's start over, and go through it step by step. First, a vinyl sliding door will have dual pane glass in it, instead of the single panes of glass found in the older aluminum doors. You can tell that your glass is Dual pane because, even though the glass is shattered all over the place, there will still be a solid piece of glass in the frame. Now, if the impact that caused the glass to shatter was from something like a bullet, there is a possibility that both panes in the frame would shatter, but that is rare. If you are replacing the glass because of condensation or moisture, that only occurs in dual pane units.

Ok, the first thing you want to determine is the thickness of each piece of glass, as well as the overall thickness of the dual pane unit. If the glass is broken, it's pretty simple to do. Just measure the thickness of the broken piece to determine the glass thickness, then measure from the remaining solid piece to the outside edge of the broken piece, and add the thickness of the glass to that measurement. That will give you the overall thickness. Next, you need to determine the width and height of the dual pane glass unit. There will be snap in plastic stops around the edges of the glass. These can be on the interior or exterior, so you need to look closely for pieces of plastic that are about 1/2" wide. Take a thin screwdriver blade or other such object and place it in the groove between the plastic stop and the door frame. Pry away from the door frame to release the stop, then pull it out. Do this to all 4 stops. Once the stops are out, it will expose the edges of the dual pane glass unit. Simply hook your tape measure on one edge, and pull the tape accross to the other edge to determine the overall width of the unit. Do the same thing from top to bottom to determine the height. Now, you can order a new Dual pane unit using the measurements for width, height, glass thickness, and overall thickness.

When the new unit arrives, it's time to remove the old one. The glass is held to the frame with either silicone or tape. If yours has tape, the home repair Gods have smiled down upon you. These come out rather easily. Buy a utility knife, the kind with the retractable blade, and wedge the blade between the glass and door frame on the opposite side than the side that had the stops. Start at the top corner, and cut away the tape on top, then down one side, then down the other side, and finally, on the bottom. The good piece of glass and the spacer will come out. There should be a couple of rubber setting blocks on the bottom. Be sure to save those, and install them back on the bottom before installing the new glass. Now, you have to clean off the tape that remains on the door frame, and either replace it with a tape of the same thickness, or if the tape was 1/16" thick or less, you can substitute silicone in place of the tape. If you ever have to replace that glass again though, you will curse yourself for using silicone. If you are using the tape, spray the bottom piece and the lower 12 inches of each side piece with glass cleaner just before setting the new glass in place. You do this to reduce the sticking properties of the tape in case you accidently touch the tape with the glass before it is in position. In most cases, it will take 2 people to install the new glass. It can be heavy. You want to each grab a side and lean the top out while setting the bottom on the rubber setting blocks. Before raising the top, make sure the unit is centered in the frame. Then, raise it up until the glass meets the tape or silicone all the way around. Apply pressure all the way around the edge to contact the glass to the tape or silicone. Once the glass cleaner evaporates from the tape, it will stick to the glass. Install the plastic stops and you are done.

Now, what if the old glass is held in place with silicone instead of tape? Frankly, I would be inclined to hire someone to do the job, but if you are the type who likes a challenge and has patience, give it a shot. You want to wedge a stiff blade putty knife between the glass and frame, where the silicone is. You start at the top corner and keep prying the old glass away from the door frame, until you have separated all 4 sides. This can take quite some time to accomplish, so be patient. there is also a possibility that the solid piece of glass will shatter when attempting to pry it out, so wear safety glasses, and lay a sheet down to catch the shattered glass. You don't have to be concerned with cuts, since the glass breaks into tiny, round pieces. You might want to contact a local glass shop before attempting the job yourself, to get an estimate for them to do the entire job for you. That way, you can see how much money your time and effort is going to save you before you start.

John Rocco has been installing replacement windows since 1978. To learn more, visit How To Install Windows