Replacement Glass & Windows
The idea of switching out your old single pane glass with newer double pane insulated glass is very good in theory. But in reality it can be almost impossible to do. Window sashes are built with a ledge or mortise that accepts the pane of glass. This part of your existing window was made to fit a pane of glass that is only 1/8 inch thick or so. If you put insulated glass that is typically about one half inch thick in this grooved space, there will be little or no space left to add your glazing compound.
