Last updated on August 30, 2021
What is glazing a window? When you hear the phrase “Window Glazing”, it actually has two meanings – glazing as the window glass itself and glazing that refers to the glazing compound used to hold the glass in place. In the most general sense, glazing is used as a broad term that refers to installing new glass panes.
Before knowing how to glaze a windowpane there are 3 main types.
Window glazing types
1. Single glazed window
Windows that have only a single sheet of glass. Outdated, inexpensive, and the least energy efficient.
2. Double glazed window
Windows with two layers of glass with a space in between that house an insulating agent such as argon gas.
This is the most common type of modern glazing for thermal and sound insulation.
3. Triple glazed glass
Windows with 3 sheets of glass and argon gas in between each gap. This is the least common, best insulated, and most expensive type of glazing.
Generally used in rooms facing a loud highway to reduce noise transmission.
What causes broken window seals?
Before we look into how to glaze a window, let’s find out why you need to glaze a window.
The primary function of a window seal is to keep humidity and the draft out. In the case of double and triple glazed windows, a broken seal causes humid air to seep through, resulting in fogging or worse.
Causes of seal failure:
What happens when window seals are broken?
Window glaze putty vs culk
#1 Glazing putty
Sealing material that’s usually a combination of linseed oil with either chalk, calcium carbonate powder, or polybutene. The highly moldable material is perfect for sealing windows around a wooden frame.
Putty needs time to fully cure and harden, but lasts indefinitely once it does, making it highly efficient. The only real drawback here is that glazing putty is limited to just glazing applications.
Consider window glazing in a tube with caulk for a quick fix.
Waterproof material used to prevent air and water leaks. Given its natural tolerances, caulk is most commonly used in plumbing applications and acts as a gap-filler or when installing and glazing a window in a door or window.
Made of silicone or as a latex window glazing in a tube, caulk is more versatile than putty but is less-lived. While putty stays after fully curing, you might need to re-apply or apply a new type of caulk every 10 years or so.
Steps in glazing a new window pane
The steps below apply to double glazed windows as the single glaze is now considered obsolete and inefficient.
Tools and materials needed
Here’s what you need when prepping a window for glazing:
- Tape measure
- Glazing putty
- Putty knife
- Heat gun
- Power sander
- Paint and applicator
- Jigsaw with glass cutting blade (optional)
Here’s how to glaze a window with putty
Step 1. Perform an inspection
This is the time to also look for and isolate any major cracks and distortions along the panes.
Before actual glazing, inspect the entire exterior of your chosen window.
Step 2. Remove the sash
This is the part of your window that shuts and opens. The sash is a long, slim piece of wood or metal usually found on the outer part of a window’s interior.
You’ll need to remove the screws on the windows that have stopped. Use a sharp knife or a chisel’s sharp cutting edge to gently cut the paint line first.
Step 3. Removing old or damaged glazing
Now that you have access to the panes, it’s time to scour the window for any damaged glazing. Remove damaged panes of glass to be replaced with a new panel of glass.
Step 4. Inspecting the wooden frame.
Once stripped of glazing, it’s now time to check the frame and patch it up for any damage.
Step 5. Glass installation
Reinstalling or replacing the glass panes.
To get the best fit, measure both sides of the frame’s opening and deduct to ⅛”.
Step 6. Applying the glazing putty
Use the putty to seal off the newly installed glass panes and finish the window. Be sure to work at room temperatures for best results.
Step 7. Optional coating
After allowing the putty to fully cure, for around 72hrs to be sure, you can coat it in oil-based primer for an additional layer of protection.
While you can opt not to paint, this method also helps extend the glazing’s longevity.
How to alter frame for bigger glass pieces?
Essentially, you’ll need to 1st measure the dimensions of the frame you wish to alter. Once you have that, next is to decide on the size of the glass you wish to install.
If you plan on putting in glass bigger than the original frame, (To recycle come glass you already have). Then first you’ll need to dismantle the frame, take out the beading, and custom-cut certain pieces to be able to fit the new pane/s.
On simple frames, you can use a wood router and a chisel to carve out or enlarge existing grooves to be able to fit a larger glass panel.
Tips for removing and reinstalling window beads
Dos and don’ts for glazing a window
Do do this
Dont do this
Safety practices for window glazing.
Should you upgrade to double glazing?
If you’re coming from single glazed windows, and your room is costing a lot to maintain heat and you want better thermal and sound insulation then definitely, yes.
Double glazing a window offers better insulation and is designed to last longer. If not for the sake of affordability, double glazed windows will make a room warmer and quieter from the outside.
If you already have double glazed windows installed, then just consider maintenance when needed such as cleaning, if you have the budget, maybe upgrade to triple glazing in extremely cold conditions or if you’re next to a noisy highway.
Who would’ve guessed that there’s actually so much when it comes to windows? Glazing, more than it is on donuts, is an essential and necessary part of window manufacturing and functionality because it is what’s responsible for allowing windows to keep humidity and water out while letting the sun in.
The reason why houses are able to hold changing internal temperatures and let you see outside is because of window glazing – as they provide insulation and climate control.
So, the next time you experience a draft despite having the windows closed, give them a quick look, they might only need a re-glaze.
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