So, What Is a Window Extension Jamb Exactly?
If you've spent any time looking at your window frames lately and wondering why there's a gap between the glass and your interior wall, you're likely trying to figure out what is a window extension jamb and why it's there. It isn't a piece of high-tech machinery or some complicated architectural secret. Honestly, it's one of those simple construction components that you probably never noticed until you started a renovation or had to replace a window. In the simplest terms, it's a piece of trim or lumber that "extends" the window frame so it reaches the interior surface of your wall. ...