Through the years I have installed many types and brands of “New Construction”
windows, which have varied in sizes and complexity. I have developed a preference for
certain window manufacturers over others. However, the purpose of this blog is not to
highlight brand preference, but to educate a consumer on three factors that a skilled
carpenter must battle when installing a window unit that operates flawlessly.
The first issue is the manufacture connection of the L-Finn to the frame of the
window system. If the L-Finn is molded to the frame this will be one less headache for
your carpenter to install, along with guaranteeing a water and airtight connection to the
wall system. Many manufacturers have a frame and then attached the L-Finn to the frame
through a spline. What I dislike about this approach from the manufacture is that the L-
Finn is not always attached as well as it could be. Generally, two problems that arise from
this is the L-Finn can detach from the frame and secondly, the jamb is not always on an
even plane with the drywall, because the L-Finn is not as ridged, which can lead to interior
The second notable bullet point to highlight is the window balance hardware. The
window balance hardware is the trolley for the window sash to travel up and down on a
double hung window. The window balance hardware and track are critical in having a
long-lasting window. Unfortunately, this critical detail is not highlighted by window
manufacturers. If the window balance hardware fails, can the hardware be replaced, and
are replacements available for purchase?
The third issue that I would consider if I were purchasing windows is if the
windowsill is sloped. Some manufacturers build windows that are not sloped. If water
enters the wall cavity, serious issues can result.
The final issue that I would highlight to a consumer is the “Meeting Rail” on a
double-hung window system. The “Meeting Rail” is how the window system is engaged to
lock and unlock. It is critical that the movement on this hardware functions flawlessly
because the window will be opened and closed countless times. Although this is a simple
concept, I have installed windows which were level, square, and plumb and still struggle in
locking and unlocking the sash, which may result in a fine tune adjustment of the
hardware. Sometimes it is a matter of the hardware being broken in, but generally I have
found that this is not always the case.