How to Replace Window Panes

A cracked window pane can be a source of frustration. It can also be a chance to upgrade your glass to energy-efficient or insulated windows to benefit from more comfort, higher resale value and reduced utility bills.

It's a project you can take on yourself for less than the cost of hiring a professional. You'll only require the appropriate tools and a few hours of your time.

Glass

If your single pane windows are old damaged, cracked or deteriorating, replacing them with newer insulated or tempered glass can improve energy efficiency and reduce noise while preserving the historic integrity of older homes. Most homeowners with basic hand tools can repair windows glass replacement with ease. You will also require an additional window pane, glazier's tips pliers, and latex glaze putty. If needed, you can use a heatgun to warm the old putty. Before starting, wear gloves and safety goggles as working with broken glass could cause injuries.

Begin by removing any remaining broken pieces of glass. This can be done with the help of pliers though using flathead screwdrivers can be effective in the pinch. Then, use a wood chisel, or putty knife, to take the remainder of the old putty around the frame and sash. Be careful to not scratch the window sash. Work slowly and carefully. It is recommended to do this using a sturdy ladder rather than on the ground and have someone stand below the sash to help keep it steady.

After you have removed all of the old putty, it is time to prepare the window frame to accommodate the new pane. Find the width and the height of the opening in the sash and subtract 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. You can cut the glass yourself if you have the right tools.

After putting the new pane in place After installing the new pane, apply a small amount of caulking along the edge to ensure it is weatherproof. Install a glazier’s point on both sides of the frame. This will help secure the pane. The points should not be so tight that they create friction between the sash and the frame however they should not be too loose.

Before applying the putty, make sure to knead it until it's soft and free of lumps. Then make it into pencil-sized strips. Apply the first strip to the corner of the frame. Work from one corner to the next to ensure it's even and smooth.

Glazier's Points

The glazier's points are tiny triangular pieces of metal that allow glass to be secured into the window screen replacement frame without causing damage to the delicate surface. It's easy to learn how to use this hidden tool, and you'll be able to save money on the cost of an installation by a professional.

Once the old putty and the glazier's points have been removed, thoroughly clean the frame with a utility knife to eliminate any remaining traces. If needed, lightly sand the wood along the grooves of the rabbets to smooth out rough areas. If you do sand your wood, ensure you protect it by using painter's tape to prevent accidental damage.

Write down the dimensions of the frame. Take these measurements to a hardware store or a home center and have the new pane cut smaller than the frame's opening. This will ensure that the pane fits perfectly and allows for expansion and contraction.

Place the new pane into the frame and press it into place firmly by using your hands. Utilize the point of the chisel, or the back of the putty blade to tap the glazier's points, as illustrated in Figure 11. The glazier's points should be in line with the top edge of the pane and the shoulders should be just beneath that lip.

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

Install the new window sash once the glazing compound has dried. First, saturate the wood with a thick coat of Linseed oil. This will prevent the new putty from soaking up the moisture and drying out and cracking with time. Use a brush to apply this coat, or the point of the blade. Then, use the chisel that is on the back of the tool or the back of the handle to gently hammer the new sash or glazier's tip into the grooves of the rabbet. Repeat this process at intervals of 10 inches all around the frame.

Putty

A baseball hit or a rock thrown by error or a branch falling can result in a cracked or cracked window pane. Fortunately, the majority of windows can be replaced by simply putting a brand new piece of glass in its the proper place. The glass is held in place by tiny metal clips known as a glazier's point, and putty, often called glazing compound. Before you install a new pane, first take out the old one and clean up the area with an abrasive and an abrasive scraper that is a pull type or a wood chisel. Wear protective glasses and gloves while doing this work. If the window is glued to the frame, you'll have to use a heat gun to soften the adhesive prior to cutting it loose.

If you're planning to replace your original sash, remove the molding that supports the old pane. Sand the sash until it is flat and ready to receive new caulk. Once the sash is installed and sanded, apply a fresh silicone caulk to the glass to ensure it won't leak or discolor over time.

Remove the glazing points from the rabbets, or the grooves in the sash, where the glass sits. If they're difficult to chisel, use the hand tool, such as a heating gun over them to allow them to soften before. When using a heat tool, be careful to not damage the sash and its railings.

Create the bed for your new pane by removing the old putty and glazing points. Roll a piece of glazing compound between your hands, shaping it to be around 1/2-inch thick. Press it into the rabbets, where the glass will be put. It is essential that the glass rests against the putty in all places on both sides, so if you need to, lightly tap the glass into the rabbet with your thumb.

If the new pane is cracked, you can use the silicone caulk or glass glue based on solvents to cover the crack before pressing it into the sash. In other cases, you'll need to apply putty over the crack to form a tight seal and keep water out. When the putty dries then clean the oily film off the glass using a rag and allow it to dry completely prior to painting. If you paint before the putty has completely dry, it won't create a strong seal and may leak or discolor in time.

Paint

If you've experienced a broken window pane, you may be worried about the cost of a new one. In reality, replacing a single pane glass doesn't have to be costly if you do it on your own. In fact even windows with double panes can be replaced at only a fraction of the cost of a professional.

If you are working on a large-sized window, make sure that it is securely fastened to the frame. With the right tools and techniques to make this task relatively easy and quick.

Once you're ready to begin taking off the old window by prying out the metal glazing points that are connected to it. These are tiny triangles of metal that act as "nails" to hold the window in the frame. They are buried under a bead of glazing putty that transforms into a solid molded wedge that holds the window firmly in place and conceals the window's points.

After removing the old pane, clean the frame and wood. Scrape away any old paint and sand down the rabbet grooves where the glazing points used to be. These should be sanded down to bare wood, 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 to prolong the life of the frame.

Then, take measurements of the dimensions of the window opening. You'll need to determine the horizontal and vertical dimensions of the entire opening, as well as the thickness. Subtract 1/8 inch from each measurement to ensure that you get a precise size for the new pane. This will also allow for expansion and contraction of the glass during seasonal changes. Take these dimensions to the hardware or home improvement store and have the replacement glass for windows near me 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.