How to Replace Window Panes

A damaged window pane can be a nuisance. It can also be an opportunity to upgrade your glass to energy efficient or insulated windows to enjoy benefits such as more comfort, higher potential for resales, and less bills.

It's a task you can do yourself for less than the cost of hiring a professional. It requires the right equipment and an hour or two of your time.

Glass

Replace your old single-paned windows with tempered insulation glass to improve the efficiency of your energy, reduce noise, and preserve the original character of your older home. The replacement of windows is simple and can be done by anyone with basic hand tools. In addition to a replacement pane, the following items are required: latex glazing putty; Glazier's points; pliers and an electric heater to warm the old putty if required. Before starting, wear gloves and safety glasses as working with broken glass may cause injuries.

Take out any broken glass pieces remaining. It is recommended to use pliers, but a flathead can be useful equally. Use a wood chisel, or putty knives to remove any remaining old putty around the frame and window sash. Work slowly and carefully, taking care not to damage the old window sash. It is recommended to do this on a stable ladder instead of the ground, and to have someone stand below the sash to help keep it in place.

Prepare the window frame to accept the new pane once you have removed the old putty. Measure the width and height of the sash opening, subtracting 1/8 inch from each measurement (to allow for seasonal expansion and contraction). Take these measurements to an 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 have the right tools.

After putting in the new pane, run a small bead of caulking around the edges to make it weatherproof. Then, you can install a glazier's pointing on each side of the frame to secure the pane into 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, make sure to knead it until it's soft and free of lumps. Roll it into pencil-sized strips. The first strip should be placed to the corner of the frame, working from one corner to another so that it is even and smooth.

Glazier's Points

The glazier’s points are small triangular pieces of metal that allow glass to be secured to the frame without causing damage to the delicate surface. It's easy to learn how to use this hidden tool and you can save money on the cost of an expert installation.

After the old putty and the glazier's point are gone, thoroughly clean the frame with a knife to eliminate any remaining residue. Lightly sand the wood in the rabbet grooves, if necessary, to smooth out rough areas. If you sand wood, protect it with painter’s tape to prevent accidental damage.

Write down the exact dimensions of the frame. Bring these measurements to an hardware store or home center and repaired have the new pane cut smaller than the frame's opening. This will ensure a tight fit and will allow room for expansion and contraction.

Place the new pane in the frame and push it in place with your hand. Use the chisel's point, or the back of the putty knife to tap the glaziers' points as shown in Figure 11. After you're done, the points should be flush with the top edge of the pane, and the shoulders that are raised of the points should be just below the rabbet's lip. groove.

Apply a thin layer of glazing compound over the edges of the new glass and into the rabbet grooves to seal and protect them. Allow it to dry and cure completely.

Install the new window sash after the glazing compound has dried. The first step is to coat the wood with a heavy coat of Linseed oil. This will keep the new putty from sucking up the moisture and drying out and cracking over time. Apply this coat with a brush or the tip of your knife, then use the chisel or the back end from the putty knife to gently hammer the new sash and glazier's points into the rabbet grooves. Repeat this process at intervals of 10 inches all around the frame.

Putty

A baseball thrown at you or a rock that is errant or falling branch could cause a window to break or crack. Fortunately, windows can be repaired by simply putting a new piece of glass in its the right place. The glass is held in place with a small metal clip called a glazier's point and putty, also called glazing compound. Before installing a replacement pane, first take out the old one and clean the area using the help of a rag, a pull-type paint scraper or an abrasive wood chisel. Wear safety glasses and gloves while doing this work. You'll require a heat gun in the event that the window is glued to the frame.

If you are planning to replace window handles the original sash, gently remove the molding pieces that are used to secure the old pane. Then you can sand the sash down to ensure it's smooth and ready for a new caulk. Once the sash is re-installed then, apply a new caulk made of silicone around the glass to ensure that it will not leak or change color in time.

Remove the glazing points from the rabbets. These are the grooves in the sash, which is where the glass is. If they're difficult to cut out, try placing a hand tool like a heat gun to soften them first. When using a heat tool, be sure to not scratch the sash's railings and repaired sash.

Create the bed for your new pane after you have removed the old glaze and putty. Roll a rope with glazing compound between your fingers and make it around 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 necessary, lightly tap your glass into the rabbet using your thumb.

If the new pane has a crack, you can cover it with a solvent-based glass glue or silicone caulk prior to pressing it into the sash. If the crack is not sealed, you will need to use putty to keep the water out. After the putty has dried clean the oily film from the glass and let it dry completely before painting. If you paint before the putty is fully dry, it won't create a solid seal and could be leaking or discoloring in time.

Paint

If you've experienced a broken window pane, you might be worried about the cost of a new one. The truth is, replacing a single pane glass doesn't need to be costly when you do it on your own. In fact even windows with double panes can be replaced at less than the cost of a professional.

If you're working with large glass windows, first make sure it is securely attached to the frame. This job can be made relatively simple and quick with the proper tools and techniques.

When you're ready to start taking off the old window pane by removing the glazing points of metal that are connected to it. These are essentially small metal triangles that act as "nails" that hold 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 that secures the window in place and hides the points.

After you have removed the old pane taken away, clean up the surrounding frame and wood. Scrape off any old paint, and sand the rabbet grooves that the glazing points were placed. Sand them to bare wood surfaces, so that you can paint the frames with the same color. After sanding, apply a coat of flax oil on the wood that is not sanded down to extend the life of the frame.

Then, you need to measure the size of the window's 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 you have the exact size for the new pane. This will also allow for expansion and contraction of the glass during seasons of change. You can bring 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.