How to Replace Window Panes

A cracked window pane can be a nuisance. It could be a chance to upgrade your windows to energy efficient or glazier insulated ones to enjoy benefits such as improved comfort, higher resale value and reduced utility costs.

You can do it yourself for a less than what it would cost to employ an expert. You only need the right tools and a few hours of your time.

Glass

If your single pane windows are old broken, deteriorating or damaged replacing them with more modern glass that is tempered or insulated will improve energy efficiency and reduce noise while also preserving the original character of older homes. The replacement of a window pane is relatively easy and can be accomplished by anyone with basic hand tools. In addition to a new pane, the following components are needed such as 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 can cause serious injuries.

Take away any broken glass pieces remaining. This is best done using a pair of pliers, however, a flathead screwdriver can also be effective in a pinch. Then, use a wooden chisel or putty knife to take the remainder of the old putty from the frame and the sash. Be careful and slow making sure not to break the current window sash. This can be done best on a ladder, not the ground. Also, have someone below the sash hold it steady.

Once you've removed all the old putty, it is time to prepare the window frame to accommodate the new pane. To allow for seasonal expansion or contraction and contraction, subtract 1/8 inch from the measurements of the width and height. These measurements can be sent to an hardware or home centers store to have cut a piece of stock glass to the right size. You can cut the glass yourself if you have the appropriate tools.

After installing the glass 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 secure the pane into the right place. The points should not be so tight that they create friction between the sash and frame, but they also shouldn't be too loose.

Before applying the putty work it in a gentle manner until it's 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 to ensure it's even and smooth.

Glazier's Points

The glazier's points are small triangular pieces which help to secure glass into a window frame without scratching or damaging the delicate surface. Knowing how to use these tiny helpers is simple and can save you money on professional installation or the cost of new glass.

After the old putty as well as glazier's points are removed, thoroughly clean the frame with a knife to remove any remaining traces. Lightly sand the wood in the rabbet grooves to smooth out rough areas. If you do sand your wood, ensure you protect it by using painter's tape to prevent accidental damage.

Take the dimensions of the frame and record precise measurements. These measurements can be taken to a home center or hardware store, and the new pane will be cut a bit smaller. This will ensure a secure fit, and allow for expansion and contraction.

Insert the new pane into the frame and press it down with your hands. Then use the point of your chisel or the back of the putty knife to pierce the glazier's points, as illustrated in Figure 11. The glazier's points should sit in line with the top edge of your pane, and the shoulders raised should be just below the lip.

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

After the glazing compound dries it's time to put in the new window sash. The first step is to coat the wood with an even layer of linseed. This will keep the new putty from soaking up the moisture and deteriorating and cracking with time. Apply the coat using a brush or the edge of your putty knife, and then employ the chisel or back end of the putty knife to gently hammer in the new sash and glazier's points into the rabbet grooves. Repeat this process in intervals of 10 inches all around the frame.

Putty

A baseball thrown at you or a rock that is errant or a falling branch can cause a window to break or crack. Most windows can be replaced by putting in a new piece. The glass is held in place by a small metal clip called a glazier's point and putty, which is often called glazing compound. Before installing a new pane, first take out the old one and clean up the area using an abrasive and an abrasive scraper that is a pull type or a wood chisel. Wear safety glasses and gloves while working. You'll require a heat gun when the window is fixed to the frame.

If you plan to reinstall the original sash in the future, take care to remove the molding pieces that are used to secure the old pane. Then sand the sash to ensure it's smooth and ready for new caulk. After the sash has been reinstalled, you can apply a silicone caulk over the glass. This will ensure that it doesn't be leaking or fade over time.

Remove the glazing points in the rabbets. These are the grooves in the sash, where the glass is. If they're difficult to cut out, you can try holding a hand tool like a heat gun to soften them before you do. When using a heated tool, make sure to avoid damaging the sash's railings and sash.

Create the bed for your new pane by removing the old glaze points and putty. Roll a piece of glazing compound between your hands, and form it to be about 1/2-inch thick. Place it into the rabbets, where the glass will be placed. The glass must be positioned against the putty on both sides. If you need to, lightly tap your glass into the rabbet with your thumb.

If the new pane is cracked you can fill it with a solvent-based glass glue or silicone caulk prior pressing it into the sash. If not, you'll have to apply putty on the crack to form an airtight seal and keep water out. Once the putty is dry remove the oily film off the glass and let it dry completely before you paint. Paint after the putty has completely dried. It will not create a solid seal and could be leaking or discoloring over time.

Paint

If you've experienced a broken window pane, you might be concerned about the expense of a new one. However, replacing one glass pane does not require a huge amount of money if you do it yourself. Even a double-paned window could be replaced for a fraction of the price it would cost an expert.

First, if you are working on a large window, make sure that it is securely attached to the frame. With the right tools and techniques, you can accomplish this task fairly easily and quick.

Once you're ready to begin, begin by removing the old window pane by removing the glazing points of metal that are connected to it. These are tiny triangles of metal that function as "nails" that hold the window in place. They are submerged beneath a layer of glazing putty, which hardens into a solid, molded wedge that secures the window screen replacement in place and hides the window's points.

After removing the old pane, clean the frame and the wood. Scrape off any paint that has been used and sand down the rabbet grooves where the glazing points were. These should be sanded down to the point of being bare, to allow you to paint them the same shade as the rest of the frame. After sanding, apply a coat of flax oil on the wood's surface to prolong its life.

Next, measure the size of the window opening. You'll need 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 during seasonal change. Take these dimensions to your local hardware or home improvement store, and they will 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.