How to Replace Window Panes

A damaged window pane could cause a lot of trouble. It could be a chance to upgrade to energy-efficient windows or insulated ones and enjoy advantages like improved comfort, higher resale value and lower utility costs.

This is a project you could take on yourself for a fraction of the cost of hiring an expert. It requires the right tools and only an hour or two of your time.

Glass

If your single pane windows are old broken, deteriorating or damaged replacing them with modern glass that is tempered or insulated can increase energy efficiency and decrease noise while maintaining the original character of older homes. A majority of homeowners with hand tools can repair windows with ease. You will also require an additional window pane, glazier's suggestions, pliers, and latex glaze putty. If needed you can use a heating gun to warm the old putty. Wear safety glasses and gloves prior to beginning. Working with broken glass can cause serious injuries.

Begin by removing any broken pieces of glass. It is best to use pliers however a flathead could work as well. Make use of a wood chisel or putty knives, to take away any remaining old putty around the frame and the window screen replacement sash. Be careful not to break the window sash. Take your time and work slowly. This is best done on a ladder, not the ground. Also, ensure that someone below the sash ensure it is held steady.

Prepare the window frame to accommodate the new pane once you have removed the old glue. Take measurements of the width and height of the sash opening by subtracting 1/8 inch from each measurement (to allow for seasonal expansion and contraction). Take these measurements to a hardware store or home center and find a piece glass cut to size. Alternatively, you can cut the glass yourself if you have the right tools.

After putting in the new glass Apply some caulking around the edge. This will make the glass weatherproof. Then install a glazier's point on the frame's opposite side to secure the pane into the right place. The points shouldn't be so tight that they cause friction between the sash and the frame, but they also shouldn't be loose.

Before applying the putty, work it in a gentle manner until it's soft and free of lumps. Roll it into pencil-sized strips. Place the first strip to the corner of the frame, moving from one corner to the other to ensure it is smooth and even.

Glazier's Points

The glazier's points are small triangular pieces of metal that help secure the glass to the frame without causing any damage to the fragile surface. It's easy to understand how to use this secret tool, and you'll save money on the expense of an installation by a professional.

After taking off the old putty, replace window pane glazier points as well as any remaining residue, clean the frame thoroughly using an utility knife. If necessary, lightly sand the wood in the grooves of the rabbets to smooth out rough areas. If you sand wood, protect it with painter’s tape to protect it from damage caused by accidental sanding.

Take measurements of the empty frame and note down precise measurements. These measurements can be taken to an hardware or home centers store, and the new pane will be cut slightly smaller. This will ensure that the pane fits comfortably and allows for expansion and contraction.

Place the new pane in the frame and press it in place by using your hands. Make use of the chisel's point or the back of the putty knife to smudge the glaziers' points as illustrated in Figure 11. When you're done taping, they should be level with the top edge of the pane, and the shoulders of the points should be just below the rabbet's rim groove.

Apply a thin layer of glazing compound to the rabbet grooves and the edges of the glass. This will seal and protect the edges. Allow it to dry and cure completely.

Once the glazing compound has dried it's time to put in the new window sash. First, you need to coat the wood with an even layer of linseed. This will keep the new putty from taking up moisture and drying out and cracking over time. Apply the coating using a brush this coat, or even the tip of the putty blade. Then use the chisel that is on the back of the tool or the back of the putty handle to gently hit the new sash, or glazier's tip into the grooves of the rabbet. Repeat this procedure every 10 inches along the perimeter of the frame.

Putty

A baseball hit or a rock thrown by error, or a fallen tree can result in a cracked or cracked window pane. Most windows can be replaced easily by installing a new piece. The glass is held in place by a small metal clip, also known as a glazier's point and putty. This compound is also referred to as glazing compound. Before you install a new pane, first remove the old one and clean up the area using the help of a rag, a pull-type paint scraper or a wood chisel. Wear protective glasses and gloves while working. You'll need a heat gun if the window is glued into the frame.

If you are planning to replace window pane the original sash in the future, take care to remove any pieces of molding that secure the old pane. Then sand the sash to ensure it's smooth and ready for new caulk. After the sash has been re-installed and sanded, apply a fresh caulk made of silicone around the glass to ensure it won't leak or discolor as time passes.

Take the glazing points out of the rabbets and the grooves in the sash that the glass sits. If they're hard to chisel, hold an instrument like a heat gun over them to soften first. If you're using a heat gun, be careful not to damage the railings or sash by placing the tool too closely.

Prepare a bed for your new pane after removing the old putty and glazing points. Roll a piece of glazing compound between your hands, shaping it into a 1/2-inch thick. Press it into the rabbets where the glass will be put. The glass should rest against the putty on both sides. If needed you want to tap your glass lightly into the rabbet with your thumb.

If the new pane is damaged, you can use a silicone caulk or glass glue that is based on solvents to cover the crack before pressing it into the sash. If the crack is not sealed, you will require putty to keep the water out. Once the putty is dry, wipe the oily film from the glass and let it dry completely before you paint. If you paint before the putty has completely dry, it will not form a solid seal and could discolor or leak over time.

Paint

You might be worried about replacing a broken piece of glass. In reality, replacing a single piece of glass doesn't have to be costly when you do it on your own. In fact, even a double-pane window can be replaced for only a fraction of the cost of a professional.

If you are working on a large-sized window, ensure that it is securely fixed to the frame. Using the proper tools and techniques to make this task relatively easy and fast.

If you're ready to begin, begin by removing the old window by prying out the metal glazing points that are connected to it. They are basically tiny metal triangles that function as "nails" which hold the window in within the frame of wood. They are submerged under a bead of glazing putty, which is then cured to form a solid, molded wedge that holds the window firmly in place and hides the window's points.

Once you have the old pane removed Clean up the frame and wood. Scrape away any paint and sand down the rabbet grooves where the glazing points used to be. These should be sanded down to the point of being bare, to allow you to paint them the same color as the rest the frame. After sanding the wood you can apply a layer flax oil. This will help prolong the life of the frame.

The next step is to determine the size of the window opening. You'll need to determine the horizontal and vertical dimensions of the entire opening as well as the thickness. To determine the exact size of the new pane, subtract 1/8 inch from both measurements. This will also allow for expansion and contraction of the glass in times of seasonal changes. Bring these measurements to the hardware or home improvement store, and they will have a piece cut for you.

Now, it's time to bed the new window pane. To do this, place the pane inside the frame and move it around until a 1/16 inch of putty remains between the edge of the glass and the sash on all four sides. Use a putty knife to smear the putty evenly, making sure that there isn't an excessive amount of excess putty in the corners and along the edges. When the putty dries, it can be painted with the same color as the frame to prevent water and air from leaking into the frame and causing fogging.