For many homeowners, window installation is a complex project that requires more than just placing the frame into a rough opening. There is also a process to ensure that the window is properly aligned and secured, which helps prevent leaks and energy loss. When a contractor is installing new windows, they start by cleaning the area and removing debris. Then they vacuum the area to reduce allergens and create a smooth surface for installing flashing tape. Finally, they install the interior stop moulding around the window and paint it if desired.

To get accurate measurements for the window size, contractors must first examine the rough opening. This involves a series of steps, including measuring the height and width of the frame at various points. Then they calculate the dimensions to find the optimum size of window for the opening.

The first step in this process is to measure the head jamb, which is the top horizontal board that frames the window. The next step is to measure the left side, center, and right side of the window opening. Then they take the reading of the lowest point on each of these three measurements and use the smallest measurement as the height of the window opening.

A window installer can improve the efficiency of a window by insulating the sill and sash area. They will often use a foam sealant and backer rod to fill gaps and eliminate drafts. They may also use low-expanding spray foam for a tighter seal. This method of window insulation is often less expensive than replacing the old windows and can save homeowners up to hundreds of dollars per year in energy costs.

In older homes, window installation may require removing the old sash and weight pockets. This can be done by unscrewing the sash cords and pulling out the metal weights. The contractor may also remove the sash rails, which must be cut to the proper length, and remove the sash hardware from the header. These items can be discarded or taken to a recycling facility, and the weight pockets can be filled with loose fiberglass insulation.

Once the frame is installed, a professional can test the operation of the window and check for any areas that need adjustment. They may have to nudge the side jambs of the frame in or out to make sure that they are aligned with the head jamb. They may also need to add shims under the side jambs and in the center of the sill to support the window.

When choosing a window contractor, homeowners should check that they are certified to work with the brand of windows they choose. They should also read reviews on Google and the Better Business Bureau to make sure that they are a reliable company. This will help to avoid any issues with scheduling, warranty options, and workmanship. Then, homeowners can feel confident that their new windows will be well-installed and provide years of performance.