How to Replace Window Panes

A damaged window pane could be a nuisance. It could also be an opportunity to upgrade your glass to energy-efficient or insulated windows and enjoy benefits such as more comfort, higher the value of resales and lower utility costs.

You can do it yourself for only a fraction of the cost it would cost to hire an expert. It requires the right tools and only an hour or two of your time.

Glass

Replace your old single-paned windows with tempered or insulated glass to increase the efficiency of your energy, reduce noise, and protect the historical integrity of your older home. Most homeowners with basic hand tools can replace Window Pane windows with ease. You will also need an extra window pane, glazier's tips pliers, and latex glaze putty. If needed you may use a heatgun to warm the old putty. Before beginning, wear gloves and safety glasses as working with broken glass could cause injuries.

Begin by removing any broken pieces of glass. It is recommended to use pliers for this, but a flathead can be useful equally. Make use of a wood chisel or putty knife to get rid of any old putty that remains around the frame and the window sash. Take your time and work slowly making sure not to damage the old window sash. It is best to work using a sturdy ladder rather than on the ground, and to place someone on the sash to help hold it in place.

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

After putting in the new pane, run a small bead of caulking around the edge to make it weatherproof. Install a glazier’s point on both sides of the frame. This will ensure the pane. The points shouldn't be so tight that they create friction between the frame and sash but they shouldn't be too loose.

Before applying the putty on the surface, you must knead it thoroughly until it becomes soft and free of lumps. Then, roll it into pencil-size strips. Apply the first strip to the corner of the frame. Work from corner to corner and ensure that it is even and smooth.

Glazier's Points

The glazier's points are tiny triangular metal pieces that help secure the glass into the window frame without causing any damage to the fragile surface. Learning how to use these tiny helpers is simple and could save you money on professional installation or the cost of purchasing new glass.

After the old putty as well as the glazier's points have been removed Clean the frame thoroughly with a knife to get rid of any remaining residue. Lightly sand the wood in the rabbet grooves if needed to smooth rough areas. If you sand wood cover it with painter's tape to prevent accidental damage.

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

Place the new pane into the frame and push it into the frame by using your hands. Then, you can use the point of your chisel or the back end of the putty knife to pierce the glazier's facets, as shown in Figure 11. The glazier's point should be flush against the top edge of your pane, and the raised shoulders should be just below that lip.

Apply a small amount of glazing compound over the edges of the glass that has been made and into the rabbet grooves to seal and protect them. Let it dry and cure fully.

Install the new window sash when the glazing compound has dried. First, you need to coat the wood with an even layer of linseed. This will prevent the newly-created putty from drying out or cracking as it absorbs moisture. Apply this coat using a brush or the tip of your knife, then employ the chisel or Replace Window pane back end of the putty knife to gently hammer in the new sash and glazier's tips into the grooves of the rabbet. Repeat this process in intervals of 10 inches all around the frame.

Putty

A baseball that is thrown or a rock that is errant or falling branch could cause a window pane to break or crack. Fortunately, the majority of windows can be repaired by simply putting a brand new piece of glass in its place. The glass is held into the position with a tiny metal clip, called a glazier's point and putty. This compound is also called glazing compound. Remove the old pane and clean the area using the rag, a pull-type scraper, or a wood chisel. Wear gloves and safety glasses when working. If the window is glued to the frame, you'll need to employ a heat gun in order to soften the adhesive before taking it off.

If you're planning to install the original sash, remove any pieces of molding that secure the old pane. Then, sand the sash to ensure it's level and ready for a new caulk. After the sash has been installed it is possible to apply a silicone caulk to the glass. This will ensure that it doesn't get soiled or discolor over time.

Remove the glazing points from the rabbets and the grooves in the sash window replacement that the glass sits. If they are hard to chisel, use a hand tool such as a heatgun over them for a few minutes to soften them. When using a heating tool, be careful to not scratch 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 of glazing compound between your hands, shaping it to be about 1/2-inch thick. Place it into the rabbets, where the glass will be put. The glass must be positioned against the putty on both sides. If necessary you want to tap your glass lightly into the rabbet using your thumb.

If the new pane has a crack then you can seal it with a solvent-based glue or silicone caulk before pressing it into the sash. If not, you'll have to apply putty on the crack to form a tight seal and keep water out. After the putty has dried clean the oily film off of the glass and allow it to dry completely before you paint. If you paint before the putty is completely dry, it will not form a strong seal and may leak or discolor in time.

Paint

You might be worried about replacing a damaged piece of glass. It's true that replacing a single pane of glass doesn't have to be costly when you do it on your own. Even a double-paned window could be replaced for a fraction of the price it would cost for a professional.

If you are working with large glass windows first ensure it is securely attached to the frame. This task is relatively easy and fast using the right tools and techniques.

Once you're ready to begin taking off the old window pane by removing the metal glazing points that are attached to it. These are tiny metal triangles that act as "nails", holding the window within the frame. They are submerged beneath a bead or glazing glue that hardens to an unbreakable wedge which holds the wood frame in place and conceals the edges.

Once you have the old pane taken away, clean up the surrounding frame and wood. Scrape off any paint and sand down the rabbet grooves where the glazing points used to be. Sand them to bare wooden surfaces so you can paint the frames with the same color. After sanding the wood then apply a layer of flax oil. This will help to extend its life.

The next step is to measure the dimensions of the window opening. It is necessary to take horizontal and vertical measurements of the entire opening, and also the thickness of the old pane. Subtract 1/8 inch from each measurement to ensure you get a precise size for the new pane. This will also allow for expansion and contraction of the glass in times of seasonal changes. You can take these measurements to a hardware store or home improvement shop 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.