Old windows often need new panes of glass if you can feel a draft coming from them. The glazing compound insulates the gap between a glass pane and the window frame. Reglazing a window is a straightforward process.
This glazing guide applies to new and old windows that need repair. If you're ready to glaze with expertise, keep reading! Window glazing is essential for maintaining a home's efficiency and appearance. Over time, windows can become drafty and less effective at insulating.
This guide will walk you through glazing a window, from understanding what window glazing is to the detailed steps of reglazing an old window or glazing a new one. Following these steps ensures your windows are properly sealed, enhancing your home's comfort and energy efficiency.
Let's get straight to the point
Glazing a window involves replacing or sealing the glass in a frame to improve insulation and energy efficiency. It can be done on both new and old windows. The process starts with preparing your workspace by covering the floor and wearing protective gear.
You’ll need to remove the old glass and glazing, which can involve using a heat gun and putty knife to soften and extract the old material. Once the old glass is removed, you inspect and repair the frame before inserting the new glass pane.
Glaze beads and glazing points secure the glass in place. Then, glazing putty is applied around the edges for a tight seal. After smoothing the putty with a putty knife, the window should dry for up to two weeks. Once dried, it can be painted for a clean, finished look. This process improves the window’s performance and appearance.
What Is Window Glazing?
"Window glazing" can refer to various things, including the glass, the putty holding it, or the installation method. Consider glazing windows with two or more glass panes to maximise your home's energy efficiency.
When a professional window installer mentions "glazing," they probably mean the glass used in the windows. To avoid confusion, always ask for clarification.
Procedures for Glazing a Window
What Types of Window Glaze Should You Buy?
There are two types of window glaze: oil-based and latex.
- Latex Glaze: It doesn't require painting and dries in about three days, but it doesn't last as long as oil-based glaze.
- Oil-Based Glaze: Ideal for clean finishes, but it can take weeks to cure as it doesn't start drying immediately after application.
If you're in a hurry, use latex for a clear glazing line. Otherwise, use oil-based paint for its durability.
Preparing Your Workspace
How to Prepare Your Workspace?
While you work, cover the floor with a sheet or a large cloth. Debris, such as dust, broken glass, and old glazing, will likely fall from the window frame. Use a towel or rag under the window to catch the debris and save yourself some cleanup work. It may also help to use two cloths on each side of the window to catch the dust and other particles.
What Safety Equipment Do You Need
There's always a risk of breaking glass while working with it. Protect yourself from flying fragments with eyewear or a face shield. Wear thick gloves to avoid cuts from glass. Closed-toe shoes protect your feet from fragments.
Removing the Old Pane and Glazing
How Do You Remove the Sash from the Window
The movable part within the window frame is called the sash. Before removing the sash, use a screwdriver to remove the stops and vertical bars inside the window frame, then set them aside. Fix the jam liners to the wall.
These grooved side pieces guide the sash up and down the frame. Carefully lift the sash from the frame by angling its top edge towards the outside. To make an upper sash, remove the separation beads and the small vertical rails that run between the sashes in the frame.
Removing Old Window Panes
Dismantle the glazing with a putty knife or scraper. If the glazing is old and cracked, this will be easy. If not, you can soften it by heating it with a heat gun. Be careful not to break the frame or the glass when prying out the glazing.
Wear protective gloves and keep the heat gun moving to avoid burning or breaking the glass. To prevent the glass from breaking under the heat, lay a thin metal sheet or folded aluminium foil on top of it.
Saving and Remove Old Glazing Points
Glazing points are small metal clips fastening the glass to the frame. You can find them within the remnants of the old glazing putty. Chip the glaze off the clips to remove them, then delicately extract them from the frame using pliers.
Removing the Glass from the Frame
If you plan to reuse the glass, carefully remove it from the frame. Warm the glass about three inches from the surface for fifteen to thirty seconds to loosen any leftover glaze particles. Push the glass on its edge to lift it, then set it aside until you're ready to replace it.
If you need to install new glass, break the old one and collect the shards. Gently tap the glass with a hammer, ensuring the fragments are as large as possible. Cut out the excess putty or glass around the frame. Older, single-pane windows are extremely fragile, so carefully remove the glass.
Inspecting the Frame for Damage
Apply a two-component epoxy primer to cracks in a wooden frame. After 15 minutes, wipe off any extra primer that has penetrated the wood. Fill the crack and surrounding areas with epoxy using a plastic putty knife.
After the epoxy has dried (which can take up to a day), sand it until it blends in with the wood. Start with 80-grit sandpaper, then reapply finer grit sandpaper (100 or 220 grit) if necessary. If desired, you can paint over the repaired crack with an acrylic primer and paint.
Installing the New Glass Pane
Getting a New Pane of Glass
This step is optional unless you intend to recycle the original glass. To get the window opening size, measure the height and width and deduct 0.125 inches. Get a new glass pane cut to size at a hardware store. Bring a fragment of the original glass to ensure the glass cutter uses the same thickness. Cutting and replacing double-pane glass will cost more than single-pane glass.
How to Coat the Frame with Glaze
Place a few glaze beads within the frame to secure the glass. Apply latex glaze or acrylic latex caulk to your beads for oil-based glazing. Arrange a string of beads along each edge to prepare the frame for pressing the glass.
Inserting the Glass into the Frame
Carefully position the glass within the frame atop your glazing beads. Press down forcefully while wriggling it to secure the glass. Once the glaze or caulk has hardened, slice off any excess with a putty knife. Thinner, single-pane glass requires extra caution.
Placing Fresh Glazing Points
Once the glass has been pressed, insert glazing points between the tilt and the frame. These tiny triangular metal pieces secure the glass to the frame as the glazing putty dries. On frames with 1onesides 2 inches or longer,r space glazing points approximately every 6 inches around the perimeter.
Install them using a point-setting tool or a point driver. One glazing point in the middle of each side is enough for windows shorter than twelve inches. A putty knife can delicately tap the point into position without a point driver.
Applying and Finishing the Glazing Putty
How to Apply Glazing Putty
Spread a generous amount of glazing putty around the perimeter of the glass pane. If it's too cold to make it pliable., warm it in your hands. Cut it into long strips and push them into the corners where the frame and glass meet.
Ensure no holes or spaces are in the putty, and spread it evenly along the perimeter. An alternate method involves heating the can of oil-based putty in a basin of hot water for a few minutes.s
Smoothing the Putty
Press the glazing putty and smooth it out using a putty knife. Slide the knife lengthwise to level the surface and remove any extra putty. If necessary, lubricate the putty with mineral spirits to prevent it from sticking to the knife.
Repeat as necessary by running the knife over the putty. Use only one pass per side to smooth it out for a professional look. Oil-based putty takes weeks to dry and harden, so avoid touching it once it's smoothed.
How to Clean Off Excess Glaze
Scrape off any excess glaze from the glass. Carefully trim away any extra material with a blade. If the putty has begun to set on the glass after slicing, use a scraper or gently peel it off with your fingers. Be careful not to disrupt the smoothed putty while working.
How to Let the Glaze Dry
Read the product directions to determine the drying time for the glaze. Most products require a drying period of 7–14 days, but oil-based glazing may require longer. Allow the putty to dry completely before reattaching the sash to the window frame.
It's best to wait until the glazing is dry before cleaning any stains rather than attempting to do so while the putty is still wet.
How to Paint Over the Glaze
After the glazing putty has dried, apply an oil-based primer on top. Ensure the primer overlaps the window glass by approximately 0.0625 inches to form a watertight seal over the putty. After the primer has dried, apply the final coat of oil-based or acrylic paint, overlapping it slightly into the glass for extra sealant.
Clean the glass thoroughly before painting to avoid putting putty oils under the paint. Use a small brush for precision and a smooth finish.
Types of Window Glazing
Single Glaze
Single-pane windows, also known as single-glaze, have fallen out of favour due to their low energy efficiency and ineffective soundproofing. These windows use a single pane of glass.
Double Glaze
Double-glazed windows, also called dual-pane windows, use two panes of glass spaced apart by a spacer and the air space within the opening, improving insulation. Dual-pane windows are the most popular option for energy-efficient glazing.
Clear Glass
Clear glass is completely transparent without any coatings or colours. It offers the least efficient use of energy.
Low-E
"Low-emissivity" (Low-E) refers to applying extremely thin metal or metallic oxide layers to window glass to control heat flow and block UV rays. Low-E coatings help retain heat during cold weather by reflecting it into the house.
What Is a Heat Retention Coating?
A heat retention coating is a low-emissivity coating applied to the inside of the pane, keeping more heat inside your home on chilly days.
Conclusion
Reglazing a window is a practical skill that can enhance your home's energy efficiency and aesthetics. Whether you're dealing with old, drafty windows or simply looking to upgrade, understanding the types of glazing and the step-by-step process ensures a successful project.
Following this guide, you can confidently tackle window glazing, ensuring your windows are well-sealed and long-lasting. Take time with each step, prioritise safety, and enjoy your reglazed windows' improved comfort and appearance.
Frequently Asked Questions
After placing the glass in the frame, gently press glazing points into the wood around the perimeter of the glass to hold it securely in place.
Use a putty knife to carefully smooth the putty along the edges of the glass, creating a neat, uniform seal between the glass and the frame.
Apply a thin layer of putty over the first to ensure a tight seal and fill any gaps or imperfections.
Depending on temperature and humidity levels, putty typically takes several days to dry completely.
Once the putty is fully dried and hardened, it can be painted to match the window frame or trim for a seamless finish.
