How to Replace Window Panes

A damaged window pane could be a source of frustration. It could also be a chance to upgrade your glass to energy efficient or insulated windows to reap benefits like greater comfort, a higher potential for resales, and less costs.

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

Glass

If your single-pane windows are old, deteriorating or broken replacing them with modern glass that is tempered or insulated will improve energy efficiency and reduce noise while maintaining the original character of older homes. The process of replacing the window pane is simple and can be done by homeowners with basic hand tools. You will also need an extra window pane, glazier's tips pliers, and latex glazing putty. If needed, you can use a heating gun to warm the old putty. Wear safety glasses and gloves prior to beginning. Working with broken glass could result in serious injuries.

Begin by removing any broken pieces of glass. This is best accomplished with pliers, however, a flathead screwdriver can also be effective in the pinch. Then, use a wood chisel or putty knife take the remainder of the old putty around the frame and sash. Be careful not to damage the window sash. Work slowly and carefully. It is best to work using a sturdy ladder rather than the ground and to place someone on the sash to help keep it in place.

After you have removed all 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 the width and height. Take these measurements to the nearest hardware store or home center and have a piece of stock glass cut to size. Alternately, you can cut the glass yourself if you have the tools you need.

After installing the new glass Apply a small amount of caulking to the edge. This will make the glass weatherproof. Then install a glazier's point on the frame's opposite side to hold the pane in its place. The points shouldn't be tight enough to cause 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. Make it into pencil-sized strips. Place the first strip in the corner of the frame, working from one corner to the next to ensure it is smooth and even.

Glazier's Points

The glazier's points are tiny triangular metal pieces that allow glass to be secured to the frame without causing damage to the delicate surface. Understanding how to use these little helpers is easy and could save you money on professional installation or the cost of new glass.

After the old putty and glazier's points are removed, thoroughly clean the frame using a utility knife to remove any remaining traces. If needed you can lightly sand the wood along grooves of the rabbet to smooth rough areas. If you decide to sand nearest wood, protect it with painter's tape to protect it from damage caused by accidental sanding.

Write down the exact dimensions of the frame. Take these dimensions to an hardware store or home center and have the new pane cut slightly smaller than the frame's opening. This will ensure a secure fit, and allow for expansion and contraction.

Place the new window in the frame and push it into the frame using your hand. Use the chisel's point or the back of the putty knife to tap in the glazier's points as shown in Figure 11. When you're done taping, they should be level with the top edge of the pane and the shoulders of the points should be just below the rabbet's lip. groove.

Apply a thin layer of glazing compound on the edges of the new glass and into the rabbet grooves to seal and protect them. Let it dry and cure fully.

Install the new window sash once the glazing compound has dried. First, coat the wood with a thick layer of linseed. This will prevent the newly-created putty from drying out and cracking as it absorbs moisture. Apply the coating using a brush this coat, or the point of the putty blade. Then use the chisel on the back of the tool or the back of the handle to gently hammer the new sash or glazier's point into grooves of the rabbet. Repeat this procedure every 10 inches around the frame's perimeter.

Putty

A baseball hit or a rock thrown in error or a branch falling can cause a broken or cracked window. Fortunately, the majority of windows can be repaired by simply placing a new piece of glass in its the proper place. The glass is held in place with small clips made of metal called the glazier's pointed and putty, also called glazing compound. Before installing a replacement double glazed windows pane, first take out the old one and clean up the area with an abrasive and an abrasive scraper that is a pull type or the wood chisel. Wear gloves and safety glasses while working. You'll require a heat gun when the window is fixed to the frame.

If you are planning to replace your original sash, you must remove the molding that supports the old pane. Then, sand the sash to ensure it's smooth and ready to be re-caulked. Once the sash is re-installed then, apply a new silicone caulk around the glass to ensure it doesn't swell or fade over time.

Remove the glazing points from the rabbets and the grooves in the sash where the glass sits. If they're difficult to cut out, try holding the hand tool, such as a heat gun to soften them up first. When using a heated tool, be sure to not damage the sash or its railings.

Once the old glazing points and putty have been removed, make a bed for the new pane. 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. The glass should rest against the putty on both sides. If necessary gently tap your glass into the rabbet with your thumb.

If the new pane is cracked, you can cover it with a solvent-based glass glue or silicone caulk prior pressing it into the sash. If the crack isn't sealed, you'll need to apply putty to keep water from getting in. Once the putty is dry remove the oily film off the glass and allow it to dry completely before you paint. Paint after the putty has dried completely. It will not create a solid seal and may be leaking or discoloring over time.

Paint

You might be worried about replacing a broken piece of glass. It's true that replacing a single pane glass doesn't have to be costly if you do it on your own. Even a replacement double glazed windows-paned window could be replaced for a fraction of the price it costs an expert.

If you are working with a large glass window first, ensure that it is securely attached to the frame. With the right tools and techniques, you can complete this task easily and fast.

When you are ready to start with the removal of the window pane. Take out the metal glazing points that are attached to it. These are small metal triangles which act as "nails" that hold the window in place. They are placed under a bead or glazing putty that hardens to solid wedge that holds the frame firmly in position and hides the sharp edges.

After you have the old pane removed, clean up the surrounding frame and wood. Scrape off any paint that has been used, and sand the rabbet grooves in which the glazing points were placed. These should be sanded down to bare wood, to allow you to paint them the same color as the rest the frame. After the sanding process, apply a coat of flax oil on the bare wood to extend the life of the frame.

The next step is to measure the dimensions of the window's opening. It is necessary to take vertical and horizontal measurements of the entire opening, as well as the thickness of the old pane. To determine the exact size of the new pane subtract 1/8 inch from both measurements. This will also allow for expansion and contraction of the glass during seasons of changes. Take these dimensions to the hardware or home improvement store, and they will have a piece 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.