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What You Need to Know When Replacing a Window in an Existing Wall

What You Need to Know When Replacing a Window in an Existing Wall

When it comes to home repair tasks, few options can make a more dramatic impression than replacing your home windows. But while many other jobs can be handled with a little bit of elbow grease and a good strategy, replacing a home window requires significant work and a good deal of technical knowledge.

As a result, replacing your windows is no easy feat. You’ll want to know what type of window you’ll be using, the specific plans required for replacing the window based on the size of the opening, and what items it will take to make the right fit for your new window. Here are a few thoughts you may wish to consider:

What is Your Frame’s Condition?

The condition, or even presence, of the window frame is the first significant factor in matching the proper type of window to your replacement plan. If you are constructing a new window frame, taking out a damaged frame, or otherwise exposing the wall down to the studs, consider new construction windows, also known as full frame replacement windows. Pocket replacement windows can be placed in projects where the window frame is not being removed, is in good condition and properly leveled.

The size of your window will also play a part in which type of window you should install. Replacing a window with a window that is the same size will make a pocket replacement window easier. Still, upgrading your window to a larger size will require uninstalling the previous frame and building a new frame to fit your larger window as part of a full frame installation. Thus, a full frame replacement window will be demanded for the job.

Removing the Old Frame

Choosing a full frame replacement window, as the name suggests, typically requires replacing the existing window frame, sashes and screen. This can usually be taken care of with a utility knife, screwdrivers, pry bar, hammer, putty knife and circular saw, depending on your current window.

To cushion your home exterior trim when taking out the frame, lay a block of wood between the wall material and window, and then use a pry bar to take out the existing window trim.

Full Frame Window Options

Two window styles can meet your needs when undergoing a full frame window installation: Nail fin windows and block frame windows.

Nail fin windows are frequently seen in new construction projects, or any project where the walls will be exposed to the frame (studs). These windows include a thin piece of metal connected to the window itself that goes around the perimeter of the window frame. When affixing the window to a new frame, this nail fin attaches the window directly to the house’s studs and is placed between the interior and exterior of your home.

Adding a nail fin window can be both a difficult task and may require the construction of a new window frame or removal of siding so the builder can apply the nail fin to the studs. Nail fin windows are more convenient to install in new construction (for example, when adding a room to your house), as the window is put in before the rest of the wall is built around it. Further, if you are wishing to place a nail fin window to a current wall in a section of the house where a stone or brick exterior would also have to be removed, the process might not be worth the time needed.

Block frame windows offer an option for situations where nail fin windows would be more damaging to install. These windows are created without a nail fin and are designed to be placed inside existing window flashing (the part of the window that has material to prevent water from entering into a house’s walls) with minor new construction work. This makes block frame windows a standard replacement for most older homes that already have a window structure built or homes with siding or brick exteriors that would otherwise have to be damaged or removed to install a nail fin window.

Using Your Existing Frame

Replacement pocket windows are a little different than full frame replacement windows and are built to be placed inside an existing window frame. While the existing window sashes and exterior stops of the window should be taken out for the new window to be installed, pocket replacements allow homeowners to retain the original frame, trim, siding and casing.

Just as with full frame window replacement, the wall exterior surrounding the window opening will impact how the pocket replacement process works, this time with fewer steps. Different from full frame replacement window removal, a good deal of the existing sash, hinges and operating hardware will be adjoined with screws that must be uninstalled before pulling out the head, jamb and sill stops with a pry-bar. As with the full frame replacement window, using a piece of wood to protect your wall exterior when taking out the old window is a smart way to help defend against any incidental damage.

After removing the existing sashes and inspecting and readying the opening, the replacement window can be set into the opening and existing frame. Make sure to plumb, level and square the window at each step of the installation to make certain your window has a proper, balanced fit.

Consult with a Professional Installer

The steps required to replace a window in an existing wall need a clear understanding of your design goals and a precise installation of your window. You can see detailed step-by-step installation manuals based on both the style of window, as well as the type of window opening, at

Even with these specific instructions, many homeowners find that the idea of unintended damage to their home (as well as the time, expense and labor required) make window installation a project they’d rather not undertake. Planning with a professional home window installation expert, like the staff at Pella of Syracuse, provides the technical knowledge and know-how to do the job safely.

Wherever you are in your home window replacement project, get in touch with a Pella professional today. Even if you are considering replacing a home window on your own, a window installation pro can help determine what installation method is best for your home and discuss installation approaches.

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