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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 solutions can make a more dramatic change than replacing your home windows. But while many other projects can be taken care of with a little work and a good strategy, replacing a home window needs serious work and a good deal of technical knowledge.

So, replacing your windows is no easy task. You’ll want to understand what type of window you’ll need, the specific tasks required for replacing the window based on the size of the opening, and what tools it will take to create the proper fit for your new window. Here are a few concerns you may need to consider:

What is Your Frame’s Condition?

The condition, or even presence, of the window frame is the first prominent factor in matching the correct type of window to your replacement project. If you are creating a new window frame, removing a damaged frame, or otherwise exposing the wall down to the studs, consider new construction windows, also called full frame replacement windows. Pocket replacement windows can be placed in projects where the window frame is not being replaced, is in good condition and properly leveled.

The size of your window will also play a part in which style of window you should use. Replacing a window with one that is a similar size will make a pocket replacement window easier. But, 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. Because of that, a full frame replacement window will be needed for the job.

Removing the Old Frame

Using a full frame replacement window, as the name implies, typically means replacing the current window frame, sashes and screen. This can typically 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 uninstalling the frame, lay a block of wood between the wall material and window, and then use a pry bar to remove the old window trim.

Full Frame Window Options

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

Nail fin windows are often use in new construction projects, or any remodel where the walls will be taken down to the frame (studs). These windows have a thin piece of metal added to the window itself that runs around the edges of the window frame. When installing the window to a new frame, this nail fin connects the window directly to the house’s studs and is hidden between the interior and exterior of your home.

Installing a nail fin window can be both hard work 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 better to install in new construction (for example, when adding a room to your house), as the window is placed before the rest of the wall is built around it. Plus, if you are wanting to install a nail fin window to a present wall in a section of the house where a stone or brick exterior would also have to be replaced, the task might not be worth the time required.

Block frame windows bring an option for jobs where nail fin windows would be more difficult to install. These windows are created without a nail fin and are designed to be placed inside existing window flashing (the section of the window that has material to prevent water from entering into your walls) with little new construction work. This makes block frame windows a standard replacement for a number of older homes that already have a window structure built or walls with siding or brick exteriors that would otherwise have to be impacted or removed to install a nail fin window.

Using Your Existing Frame

Replacement pocket windows are somewhat 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 removed for the new window to be added, pocket replacements allow homeowners to retain the original frame, trim, siding and casing.

Just as with full frame window replacement, the wall exterior around the window opening will play a role in how the pocket replacement process works, however with less steps. Different from full frame replacement window removal, much of the existing sash, hinges and operating hardware will be adjoined with screws that must be taken out before pulling out the head, jamb and sill stops with a pry-bar. Similar to the full frame replacement window, placing a piece of wood to shield your wall exterior when removing the old window is a smart way to help avoid any unintended damage.

After taking out the existing sashes and inspecting and preparing the opening, the replacement window can be placed into the opening and existing frame. Remember to plumb, level and square the window at each step of the installation to have the best chance for a proper, balanced fit.

Consult with a Professional Installer

The requirements needed to replace a window in an existing wall demand a clear understanding of your design goals and a exact 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, most homeowners discover that the chance of incidental damage to their home (as well as the time, cost and labor required) make window installation a project they’d rather not undertake. Working with a professional home window installation expert, like those at Pella of Westerly, provides the technical knowledge and know-how to do the job correctly.

Whatever part you are in in your home window replacement project, call a Pella professional today. Even if you are planning on replacing a home window on your own, a professional can help you decide what installation method is best for your home and discuss installation options.

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