At the glass repair company where I work in Philadelphia, Pennsylvania, at least once a week we get a call from a business or owner with a broken double pane window asking if we can replace it with a single pane of glass.
Why the heck, you ask, would anyone want to replace a double pane window with a single pane? There are two reasons for this. One is the time factor. Double pane windows (also referred to as thermal or insulated windows) need to be custom ordered and typically take five to ten business days to manufacture, while installing a single pane in the opening is something that can be done from that. way. the same day. The other reason is cost. As you might imagine, a double pane window is more expensive. After all, a single pane of glass is just that. In contrast, a thermal window, in addition to obviously having two panes of glass, also has quite a bit of built-in technology. And the technology is not cheap. Replacing a large double pane window can be a significant expense.
As far as actual work is concerned, converting a double pane business window into a single pane is a relatively straightforward affair. For modern storefront glazing (known as “flush glazing”), manufacturers sell a simple converter system that fits into the existing frame and reconfigures it to a single glazing width. However, converting a residential window is a different story. Residential sash and sash are designed to hold a double pane window (known as a “unit”) of a very specific thickness, and due to the proprietary nature of residential windows and certainly a general lack of demand, there is no such thing as a converter system. For this task. But that doesn’t mean it can’t be done. And well done.
Quite regularly I run into a landlord or, more typically, an apartment dweller who, for one reason or another, absolutely insists that they have their double-pane window repaired that very day. It is for these clients that I have developed the following method to perform such a repair, the result of which is semi-permanent (can be easily reversed) and has a watertight seal.
After removing and disassembling the sheet, then removing the glass from the old thermal unit, a single piece of flat glass with a thickness of 3/16 or 1/4 inch (as opposed to the two pieces of 5/32 glass of an inch which is usually found in residential thermal windows) is cut to a size that fits the sash perfectly and is laid flat in a continuous line of silicone on the inside of the outside side of the frame. Next, 1/16 inch thick neoprene mounting blocks are placed along the edge of the glass, two per side. These act as a very effective buffer between the glass and the sash, and prevent the glass from moving in either direction.
Next, a second bead of silicone is placed around the edge of the inner side of the glass. Finally, a series of carefully sized small wooden blocks (typically two or three for each side) are wedged between the inner side of the sash and the glass, forcing the panel against the outer side of the sash. Then the window is put back. -installed. After the silicone cures in 72 hours, the customer takes out the wood blocks and voila.
I have been doing this type of window repair for almost 15 years and have never had a single callback or complaint. However, there are two caveats that must be explained to the client before agreeing to do the job. The first is obvious: they lose the thermal properties of having a double pane window. The second is that while the window will look the same from the outside, there will actually be a 1/2 to 3/4 inch gap inside the sash. After all, if you put 1/4 piece of glass into an opening that is 7/8 inch, you still have a 5/8 inch difference. As is, the inside of the blade is the same color as the outside, so the visual difference is negligible.
And there you have it.