How to Replace a Sliding Glass Window

What You'll Need
Tape Measure
Pry bar
Foam Insulation

A sliding glass window is much like a sliding glass door in that is opens on a horizontal track. They are very common in some older homes, mobile homes, and RV's. The great thing about a sliding glass window is that they allow quite a bit of air over a crank out window. There are times when the sliding glass window needs to be replaced. This is a simple project that can be done in a short period of time.

Step 1: Measure Opening for New Glass Window

Before you can remove the old sliding glass window you must measure it for a replacement piece. Take the measurement with you when you order a new sliding glass window.

Step 2: Remove Windows

There are different manufacturers of sliding glass windows so there are different ways to remove the windows. Look for some adjusting knobs on the top and bottom of the frame. They are used to adjust the tension on the sash for it to slide. Loosen these adjusting knobs in order to remove the individual sliders.

Step 3: Remove Old Window Frame

Once the individual window sashes are removed you will have a frame left in the opening. Look at the inside of the frame and locate any nails or screws holding it in place. Remove the screws with a drill. You may have to use a reciprocating saw on the nails. Simply slide the blade in between the frame and window opening and cut the nails.

Step 4: Prepare Opening

With the old window removed from the opening, you need to clean out the area for the new sliding glass window. Remove any nails that are sticking up, repair any damage to the wooden frame, and clean out any dirt and grime.

Step 5: Place Caulk Along Perimeter of Frame

Before you set the new sliding glass window into the opening. apply a bead of caulk around the perimeter of the frame.

Step 6: Install New Sliding Glass Window

Lift the new window into position and set it into the frame. Center it in the frame and make sure it is level. You may have to use some shims around the window frame in order for the window to be level and plumb. Take the time necessary to do this for better window operation. If there are no glazing points in the window frame, they should be installed for easier window installation.

Step 7: Secure Window to Window Opening

Once the window frame is level and plumb you can then secure it with the included screws. Drill them in at a slight angle for better holding power.

Step 8: Install Sliding Windows

Place the sliding windows into the frame and adjust the tension on the rails. Work them back and forth a few times to make sure they work without sticking.

Step 10: Cut Shims and Install Trim

Cut the shims that were used in leveling off the window. Cut them as close to the frame as possible with a small coping saw. Install the window trim around the outside perimeter of the window for a more finished look.