How to Replace Window Panes

A damaged or cracked window is a nuisance. It could also be a chance to upgrade your glass to energy-efficient or insulated windows and benefit from more comfort, higher resale value and reduced utility costs.

You can do it yourself for a a fraction of what it would cost to hire an expert. You only need the appropriate tools and a few minutes of your time.

Glass

If your single pane windows are old, deteriorating or broken replacing them with more modern glass that is tempered or insulated can increase energy efficiency and decrease noise while also preserving the historical integrity of older homes. The procedure of replacing a window pane is relatively easy and can be completed by anyone with basic hand tools. You'll also require an extra window pane, glazier's suggestions, pliers, and latex glaze putty. If necessary, you can use a heating gun to warm the old putty. Before starting, put on gloves and safety goggles as working with broken glass can cause injuries.

Begin by removing any remaining broken pieces of glass. This is best accomplished with the help of pliers but flathead screwdrivers can be used in the pinch. Then, use a wood chisel or putty knife to remove the remaining old putty from around the frame and sash. Be careful and slow and be careful not to break the existing window sash. This can be done best on a ladder, not the ground. Also, ensure that someone below the sash keep it in place.

Prepare the window replacement frame to accommodate the new pane after you have removed the old glue. Find the width and the height of the opening for the sash and subtract 1/8 inch from each measurement (to allow for seasonal expansion and contraction). These measurements can be taken to a home center or hardware store to have cut a piece of glass stock to the proper size. Alternatively, you can cut the glass yourself if you have the tools you need.

After installing the glass, apply some caulking to the edge. This will make the glass weatherproof. Then install a glazier's point on each side of the frame to hold the pane in place. The points shouldn't be too tight that they cause friction between the frame and sash However, they should not be loose.

Before applying the putty on the surface, you must knead it thoroughly until it becomes soft and free from lumps. Then you can roll it into pencil-sized strips. Place the first strip to the corner of the frame, moving from one corner to another to ensure it is smooth and even.

Glazier's Points

The glazier's points are small triangular pieces of metal that allow glass to be secured into a window frame without damaging or scratching the delicate surface. It's easy to learn how to use this nefarious tool, and you'll be able to save money on the cost of an expert installation.

Once the old putty and glazier's points are removed Clean the frame thoroughly with a knife to get rid of any remaining traces. If needed it is necessary to lightly sand the wood along grooves of the rabbet to smooth rough spots. If you decide to sand the wood, ensure you protect it by using painter's tape to prevent accidental damage.

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

Place the new pane in the frame and push it in using your hands. Then use the point of your chisel or the back end of the putty knife to tap in the glazier's points as illustrated in Figure 11. The glazier's point should be aligned with the top edge of your pane, and the raised shoulders should be just beneath that lip.

Apply a small amount of glazing compound on the edges of the new glass and into the rabbet grooves to seal and glazier protect them. Allow it to dry and cure fully.

Once the glazing compound has dried, you're ready to install the new window sash. The first step is to coat the wood with a heavy coat of Linseed oil. This will stop the new putty from sucking up moisture and deteriorating and cracking over time. Apply the coating using a brush this coat, or the tip of the putty blade. Then, use the chisel on the back of the putty tool or the back of the putty handle to gently hammer the new sash or glazier's point into the grooves of the rabbet. Repeat this procedure every 10 inches around the frame's perimeter.

Putty

A baseball that is thrown, an errant rock or a falling branch can cause a window pane to crack or break. Fortunately, the majority of windows can be replaced by simply placing a new piece of glass in its the proper place. The glass is held in the position with a tiny metal clip, referred to as a glazier’s point and putty. This compound is also called glazing compound. Remove the old pane and clean the area with a rag, a pull-type scraper or wood chisel. Wear protective glasses and gloves while doing this work. If the window is attached to the frame, you'll need to employ a heat gun in order to soften the adhesive prior to prying it free.

If you're planning to replace the original sash, take off the molding that holds the old pane. Then you can sand the sash down to ensure it's level and ready to be re-caulked. Once the sash is installed, apply a new caulk made of silicone around the glass to ensure that it won't leak or discolor as time passes.

Remove the glazing points from the rabbets. These are the grooves on the sash, where the glass is located. If they are hard to chisel, hold an instrument such as a heating gun over them for a few minutes to soften them. When using a heated tool, make sure to not damage the sash or its railings.

After the old glazing points and putty have been removed, prepare a bed for the new pane. Roll a rope made of glazing compound between your fingers, and make it about 1/2 inch thick. Press it into the rabbets where the glass will be placed. It is essential that the glass rests against the putty on both sides, so if you need to do so, gently tap the glass into the rabbet using your thumb.

If the new pane has a crack then you can seal it with a solvent-based glass glue or silicone caulk prior pressing it into the sash. If the crack isn't sealed, you'll require putty to keep water from getting in. After the putty has dried remove the oily film off of the glass and let it dry completely before painting. If you paint before the putty has completely dry, it will not form an effective seal and could discolor or leak in time.

Paint

If you've had a broken window pane, then you may be worried about the cost of a new one. But the truth is that replacing a single glass pane doesn't need to cost a fortune If you can do it yourself. Even double-paned windows can be replaced for a fraction of what it costs an expert.

If you're working with large glass windows first ensure it is securely fixed to the frame. Using the proper tools and techniques to accomplish this task fairly easily and fast.

When you are ready to start with the removal of the window pane. Remove the metal glazing points attached to it. These are essentially small metal triangles that function as "nails" that keep the window in place within the frame of wood. They are placed beneath a layer of glazing putty, which transforms into a solid molded wedge which holds the window in place and hides the edges.

After taking off the old pane clean the frame and the wood. Scrape off any paint and sand down the rabbet grooves, where the glazing points used to be. Sand them down to bare wooden surfaces, allowing you to paint the frames the same color. After sanding the wood, apply a layer of flax oil. This will help extend its life.

Next, measure the size of the window opening. You'll need to take vertical and horizontal measurements of the entire opening as well as the thickness of the old pane. Subtract 1/8 inch from each measurement to ensure that you get a precise size for the new pane. This will allow for seasonal changes in the glass. Take these dimensions to your local hardware or home improvement store and have the glass 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.