How to Replace Window Panes

A cracked window pane can be a nuisance. It could be a chance to upgrade to energy-efficient windows or insulated ones and enjoy benefits such as improved comfort, increased resale values and lower utility costs.

This is a project you could take on yourself for only a fraction of the cost of hiring a professional. It requires the right tools and only 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 increase energy efficiency and decrease noise while maintaining the historic integrity of older homes. The replacement windows panes of the window pane is easy and can be completed by anyone with basic hand tools. In addition to a replacement Glass windows pane, the following items are required such as latex glazing putty; glazier's points; pliers; and the use of a heat gun to warm the old putty, if needed. Before starting, put on gloves and safety goggles as working with broken glass can cause injuries.

Begin by removing any broken pieces of glass. This is best accomplished with pliers, however, a flathead screwdriver can also be used in the pinch. Then, use a wooden chisel, or putty knife, to take the remainder of the old putty from around the frame and sash. Be careful to not scratch the window sash. Take your time and work slowly. This is best done on an elevated ladder, not on the ground. Also, you should have someone below the sash ensure it is held steady.

Prepare the window frame to accommodate the new pane when you have removed the old putty. Find the width and the height of the opening for the sash and subtract 1/8 inch from each measurement (to allow for seasonal expansion and contraction). These measurements can be sent to an hardware or home centers store to get a piece cut of glass stock to the proper size. Alternately, you can cut the glass yourself if have 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 its place. The points should not be tight enough to create friction between the frame and sash, but they should also not be loose.

Before applying the putty to the surface, knead thoroughly until it becomes soft and free from lumps. Then make it into pencil-sized strips. The first strip should be glued 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 small triangular pieces of steel that help secure the glass to the frame without damaging the delicate surface. It's easy to learn how to use this nefarious tool and you can save money on the cost of an installation by a professional.

Once the old putty and the glazier's point are gone Clean the frame thoroughly with a utility knife to get rid of any remaining traces. Lightly sand the wood in the rabbet grooves, if necessary, to smooth out rough areas. If you decide to sand the wood, be sure to protect it by using painter's tape to prevent accidental damage.

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

Insert the new pane into the frame and push firmly with your hands. Then use the point of your chisel or back end of the putty knife to tap in the glazier's points, as shown in Figure 11. When you're done, they should be in line with the top edge of the pane, and the shoulders that are raised of the points should be just below the lip of the rabbet groove.

Apply a thin bead of glazing compound on the edges of the glass that has been made and into the rabbet grooves, to seal and protect them. Allow it to dry completely and cure.

Once the glazing compound has dried and the glazing compound is dry, you can install the new window sash. First, you need to coat the wood with an even layer of linseed. This will prevent the newly-created putty drying out or cracking due to the moisture it absorbs. Use a brush to apply this coat, or the point of the putty blade. Then use the chisel that is on the back of the putty tool or the back of the handle to gently hit the new sash, or glazier's tip into the grooves of the rabbet. Repeat this process in intervals of 10 inches around the frame.

Putty

A baseball that is thrown, an errant rock or a fallen branch can cause a window pane to crack or break. Luckily, most windows can be repaired by simply putting a brand new piece in place. The glass is held in place using tiny metal clips known as a glazier's point and putty, also called glazing compound. Before installing a replacement double glazing windows pane, first remove the old one and clean the area with the help of a rag, an abrasive scraper that is a pull type or the wood chisel. Wear protective glasses and gloves while doing this work. If the window is glued to the frame, you'll need to make use of a heat gun to soften the adhesive prior to prying it free.

If you're planning to install your original sash, remove the molding that holds the old pane. Then sand the sash to ensure it's level and ready to be re-caulked. Once the sash is installed then, apply a new silicone caulk around the glass to ensure it will not leak or change color over time.

Remove the glazing points in the rabbets. These are the grooves on the sash where the glass is located. If they are hard to cut, place a hand tool such as a heating gun over them for a few minutes to soften them. When using a heating tool, make sure to not damage the sash and its railings.

After the old points of glazing and putty have been removed, make a bed for the new pane. Roll a rope of glazing compound between your fingers, and then make it about 1/2 inch thick. Then, you can press it into the rabbets, where the glass will rest. It is crucial that the glass rests against the putty on each side If you have to, lightly tap the glass into the rabbet with your thumb.

If the new pane has cracked, you can apply a silicone caulk or glass glue based on solvents to cover the crack before pressing it into the sash. Otherwise, you'll need to apply putty over the crack to create an airtight seal and keep water out. After the putty has dried and the film is oily, wipe it off the glass with a rag and allow it to dry completely before painting. If you paint before the putty is completely dry, it will not form a strong seal and may be leaking or discoloring in time.

Paint

You may be concerned about replacing a broken pane of glass. But the truth is that replacing one glass pane does not need to cost a fortune if you do it yourself. In fact, even a double glazing window replacement-pane window replacement panes can be replaced at only a fraction of the cost of a professional.

If you are working with large glass windows, first make sure it is securely fixed to the frame. This can be done relatively easy and quick with the right tools and techniques.

When you are ready to begin, remove the old window pane. Take out the metal glazing points that are attached to it. These are tiny triangles of metal which act as "nails", holding the window in place. They are submerged beneath a bead or glazing glue that hardens to solid wedge that holds the wood frame firmly in position and conceals the edges.

After taking off the old pane clean the frame and wood. Scrape away any old paint and sand down the rabbet grooves, where the glazing points used to be. These should be sanded to bare wood to allow you to paint them the same shade as the rest of the frame. After sanding the wood, apply a layer of flax oil. This will help prolong the life of the frame.

The next step is to measure the dimensions of the window opening. You will need to take horizontal and vertical measurements of the entire opening, as well as the thickness of the old pane. Subtract 1/8 inch from each measurement to ensure that you get a precise size for the new pane. This will allow for seasonal changes in the glass. Bring these measurements to your local hardware or home improvement store, and they will have cut the glass 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.