Replacing French Door Glass

It is fairly simple to replace a damaged glass pane in the French Door. Cleaning the glass, removing trim and molding, then installing the new pane is all that's needed.

French doors feature multiple glass panes that are separated by muntin bars. These are also called Mullions. They are available in a wide variety of designs and are able to be triple-paned in order to reduce noise and control the glare.

How to replace a broken Pane of Glass

Wear rubber gloves and safety glasses before you begin to replace the glass. This will protect you from any broken glass shards that may fall during the process. Also work in a garage or another open space and keep children away from the area. It is best to remove the window frame from the sill to allow greater accessibility and mobility however, you can replace a pane without taking the entire window out of the frame.

With a putty knife use a putty blade to scrape off any caulking or glazing compound that is around the edge of the window sash. You don't want damage to the wood molding holding the window in place. It will be needed to support the new pane.

If you're working with a steel-casement windows, the window may be held in place with glazing points made of steel. You'll need to take them off as well as the old putty before you can take the window out of the frame. A paint scraper or tool like a chisel will work however, if you find that the putty is difficult to get out, slowly soften it with a heat gun. Hold the heat gun about one inch from the glass and move it around to spread the heat. Double the aluminum foil on the other panes to stop them from cracking because of the heat.

Once the old glass is removed, wipe down the inside of the window sash with a damp cloth to clean off any dirt or dust. Then you can install a new glass pane.


Take measurements of the width and height to determine the size of the glass. Take these measurements and subtract 1/8 inch from each side to create a new piece that is able to fit into the door frame. Many hardware stores will cut a piece glass for you, if you give them the measurement.

Warm a handful of putty in your hands, then roll it into a length of 3/4 inch thick. Set the putty in a position that is against one edge of the rabbet, and then rest your putty knife's blade at a 45-degree angle to the frame's rabbet. To cut a section from the pane, push the knife in a smooth and straight line along the edge of glass. Repeat the process with the other edges of the pane. Then, scrape off the excess putty.

Remove the Broken Pane

A glass pane that has been broken in the frame of a French door isn't just an eye sore it's a risk to your safety. It's easy to replace a pane of glass in a French-style door and it's usually cheaper than replacing the entire door panel. Most homeowners can handle this task themselves, though professional assistance is available in the event that the project requires special tools or skills.

Begin by removing the broken piece of glass, and cleaning up any cracked or shattered fragments from the frame. Wear safety goggles and gloves to prevent glass shards from getting into your eyes or onto your face. Clean the glass's opening to remove any caulking or putty used to keep the previous pane in place.

The next step is to take off any trim or molding that held the pane of glass in place. It can be a challenge to get the molding out. This is why it's a good idea to wear your protective gear and ask someone to assist you in the process of prying if you need help. Label the pieces you are removing so you can return them to their original location.

Installing the new glass is simple once the molding has been removed. Find the measurements of the opening in the glass pane and then go to a glass shop to purchase a piece of new glass for your French door. It is recommended to purchase the safety glass for your French door, as it will not break easily in the event of a break.

When you're ready to install the new piece of glass make sure that it's aligned correctly in the opening. Then, apply a fine bead of clear silicone caulk around the glass's edge.

You can change the molding once the caulk has dried. If the nails that were used originally did not penetrate the molding, you can hammer in new wire nails to fill in the holes left by the old nails. To stop the nails from splitting the molding, you must pre-drill the holes first. You can drill holes with very thin bits from hardware stores that are well-stocked.

Cut a New Pane of Glass

Double-check the spacing around the frame of the window as well as the edges before ordering a replacement pane. If you find any gaps, you may require adjusting the spring clips or the metal triangles that hold it in place. You should also make sure that your new pane is the right size for the opening. If it's too big there could be leaks and other issues.

The first step is to prepare the work surface. Scrape the old compound off both sides of the frame with a putty blade to expose the wood. If the rabbets are too rough to smooth with the putty knife gently sand them and apply an exterior primer. french door repairs rochester will prevent the new glazing from absorbing moisture from the wood and reduce its lifespan.

Once the frame is clean and prepped, warm a handful of putty by kneading it until it's soft and malleable. Apply a thin layer with the putty blade to the inside corners of the rabbets to create a bed that the glass can rest. Repeat the process for the other exposed edges of the rabbets.

When the putty is dry take any remaining metal glazing points from the grooves in the sash. Wear safety goggles prior to trying to remove the points in order to keep yourself safe from shards glass. A heat gun on an low setting will help you warm up and loosen the steel so that you can stretch it out of the frame using pliers.

Place the glass on the table to test the fit. Make any adjustments needed before securing it in place with spring clips or metal triangles. Ensure that the gap between the frame and glass is uniform and even on all sides, and examine the sash's movement to ensure that the new pane will not interfere with opening or closing the window. If you have any issues with the installation, you should consult an expert who specializes in restoration to assist you repair and preserve your home's historic features.

Install the Pane of Glass

Test-fit the glass pane to ensure that it fits properly before putting it up. Take measurements of the width and height of the window opening by measuring to the outside edge of the L channels. Subtract 1/8 inch from each measurement to determine the size of the glass you need to buy. It is easier to install the glass when you are a little smaller than. This will also allow for seasonal expansion and contraction of the wood frame. Bring your measurements to a hardware store or home center, and let them cut a piece of glass for you. Alternatively, you can cut the glass yourself if happen to have a huge sheet of stock glass.

Once the old pane of glass is removed, you should clean the window sash grooves and remove any glazing points made of steel that held the previous pane in place. A paint scraper that is a pull type or a chisel can be used for this task. If the grooves contain an abundance of hardened putty in them, you can gradually soften it with a heat gun. Be sure to cover the surrounding windows and molding with aluminum foil to shield them from the heat.

Scrape and sand the rabbets on which the glass is, and then brush an exterior primer over them to prevent the putty from drawing out its natural oils and thus reducing its life. You should also clean the sash to remove dust and dirt from the grooves.

Press a small amount into the rabbets where the glass will be placed. The appearance of the glass isn't crucial at this point. Place the new pane in the rabbets, then wiggle it around and apply a consistent pressure with your fingers to make sure that it's placed in the right place.

If there are holes in the frame of wood around the glass, fill them with silicone caulk prior installing the new glass. If the frame has other fastening mechanisms, like L channels, use a hammer and pry them out of the sash grooves. Check the frame for glass fragments that may have shattered during removal, and then remove them prior to continuing. Then, apply a layer of clear silicone caulk on the bottom of the frame where it connects to the floor to keep water and pests out of your home.