How to Replace Window Panes

A damaged window pane can be an inconvenience. This can be an opportunity to upgrade your windows to energy efficient or nearest insulated ones and enjoy benefits like increased comfort, increased resale values and reduced utility costs.

This is a project you could do yourself for less than the cost of hiring a professional. It requires the right tools and only an hour or two of your time.

Glass

Replace your single-paned windows with tempered or insulate glass to improve energy efficiency, reduce noise, and maintain the historic integrity of your old home. Most homeowners with basic hand tools can repair windows with ease. In addition to a replacement pane, the following tools are needed for the replacement process: latex glazing putty Glazier's points; pliers and an electric heater to warm the old putty, if necessary. Wear safety glasses and gloves before you begin. Working with broken glass could result in serious injuries.

Take away any broken glass pieces remaining. This can be done with a pair of pliers, though using a flathead screwdriver can also work in the pinch. Use a wood chisel, or putty knives to remove any old putty that remains around the frame and window sash. Be careful not to damage the window sash. Work slowly and carefully. This is best done on a ladder, not on the ground. Also, you should have someone below the sash ensure it is held steady.

Once you have removed all of the old putty, prepare the window frame for the new pane. To allow for seasonal expansion or contraction, subtract 1/8 inch each from the measurements of width and height. Take these measurements to the nearest hardware store or home center, and have a piece of stock glass cut to size. You can also cut the glass by yourself if you possess the right tools.

After installing the new glass Apply some caulking to the edge. This will make the glass weatherproof. Then install a glazier's point on the frame's opposite side to secure the pane in place. The points should not be tight enough to create friction between the frame and the sash however they should not be loose.

Before applying the putty to the surface, you must knead it thoroughly until it becomes soft and free of lumps. Cut it into pencil-sized pieces. The first strip should be glued to the corner of the frame. Work from one corner to the next and ensure that it is even and smooth.

Glazier's Points

The glazier’s points are small triangular pieces of steel which help to secure the glass to the frame without causing damage to the delicate surface. It's simple to learn how to use this nefarious tool, and you'll be able to save money on the cost of a professional installation.

After the old putty as well as the glazier's point are gone Clean the frame thoroughly with a utility knife to remove any remaining residue. Lightly sand the frame in the rabbet grooves if needed to smooth rough areas. If you decide to sand the wood, make sure to protect it by using painter's tape to prevent accidental damage.

Measure the empty frame's dimensions and record precise measurements. Take these measurements to an hardware store or home center, and have the new pane cut slightly smaller than the frame's opening. This will ensure a snug fit and will allow room for expansion and contraction.

Place the new pane in the frame and press it down using your hands. Then, you can use the point of your chisel or the back end of the putty knife to tap in the glazier's facets, as illustrated in Figure 11. The glazier's point should be in line with the top edge of your pane and the raised shoulders should be just below the lip.

Apply a thin bead of glazing compound over the edges of the new glass and in the rabbet grooves to seal and protect them. Allow it to dry and cure fully.

Once the glazing compound has dried and the glazing compound is dry, you can install the new window screen replacement sash. First, you need to coat the wood with a thick layer of linseed. This will prevent the new putty from drying out or cracking due to the moisture it absorbs. Apply this coat using a brush or the tip of your knife, then use the chisel, or the back end of the knife to gently press the new sash and glazier's tips into the grooves of the rabbet. Repeat this process at intervals of 10 inches around the frame.

Putty

A baseball hit, a rock thrown in error, or a fallen tree could result in a broken or cracked window pane. Most windows can be replaced by putting in a new piece. The glass is held in place with small clips made of metal called the glazier's pointed and putty, often called glazing compound. Remove the old pane and clean the area with a rag, a pull-type scraper or nearest wood chisel. Wear gloves and safety glasses while doing this work. You'll require a heat gun if the window is glued into the frame.

If you're planning to reinstall your original sash, you must remove the molding that supports the old pane. Then you can sand the sash down to make sure it's flat and ready to be re-caulked. Once the sash is re-installed, apply a new silicone caulk around the glass to ensure that it won't leak or discolor as time passes.

Take out the glazing points in the rabbets. These are the grooves in the sash, where the glass is located. If they're difficult to chisel, hold the hand tool, such as a heating gun over them to allow them to soften before. When using a heated tool, be sure to avoid damaging the sash or its railings.

Make a bed for your new pane after you have removed the old putty and glazing points. Roll a rope with glazing compound between your fingers and make it around 1/2 inch thick. Place it into the rabbets where the glass will be put. It's important that the glass rests against the putty in all places on each side, so if you need to do so, gently tap the glass window replacement into the rabbet using your thumb.

If the new pane has a crack you can fill it with a solvent-based glue or silicone caulk prior pressing it into the sash. If the crack is not sealed, you'll need to use putty to keep the water out. Once the putty is dry, wipe the oily film off of the glass and allow it to dry completely before you paint. If you paint before the putty is fully dry, it will not form an effective seal and could leak or discolor in time.

Paint

If you've suffered a break in a window pane, you might be concerned about the expense of a new one. In reality, replacing a single piece of glass doesn't have to be expensive if you do it on your own. Even a double-paned window could be replaced at a fraction of the cost it costs for a professional.

First, if you're working on a large window, make sure it is securely attached to the frame. Using the proper tools and techniques to complete this task easily and quick.

When you are ready to start taking down the old window pane. Remove the metal glazing points that are attached to it. These are tiny triangles of metal that act as "nails" that hold the window in place. They are placed under a glaze putty or bead that sets to form an unbreakable wedge which holds the wood frame in place and conceals the edges.

After removing the old pane, clean 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 of the frame. After sanding, apply a coat of flax oil to the bare wood to help extend its lifespan.

The next step is to determine the width of the window opening. You'll need to determine the vertical and horizontal dimensions of the entire opening, as well as the thickness. Subtract 1/8 inch from each measurement to ensure that you get the exact measurement for the new pane. This will allow for seasonal changes in the glass. You can take these measurements to a hardware store or home improvement shop and get 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.