September 19th, 2020 in


How to repair a broken glass window? DIY glass replacement for windows


Window glass is the easiest to get damaged. It can be your kids’ ball or the wind that banged the window doors hard. It’s not always about breaking, some fibre starts to yellow with time which spoils the aesthetics of the home.

So, how do we handle it? Calling a professional for a single-window glass change will usually cost around $200. You can potentially save 80% of the cost if you have the time and will to change it yourself. Yes, almost any kind of window glass pane replacement can be DIY-ed.

We will see how to replace window glass and reglaze by yourself with minimal tools. Don’t worry we have covered it all – wood, aluminium and vinyl frames, double glazed, sliders, mechanical fastening and everything else.



Broken window glass


Why do you need a window glass replacement?

The obvious reason for the window glass replacement is having a broken glass and its downsides of an ugly window and possibility of glass hurting people.

But what if you had a cracked or fogged glass which is about to break? Should you change it right away or wait for it to break by its own?

Ideally, anything other than the untouched state of glass is not good. Cracks might seem small from the outside that you would skip on it. But cracks in glass reduces the energy efficiency of it, especially insulated double pane windows.

Fogging means that the glass has gone beyond its lifetime. Usually fogging and yellowing glasses are brittle and are at the verge of breaking. So never leave them as such. The earlier you change, the better.

Sometimes you might have a perfect window without a crack but the latest glass tech might urge you to change. Low-E glass (less heat loss) or the Laminated glasses might be best options if you can afford to spend on it.



How to change window glass pane by yourself?


Things to note before starting the window glass replacement process

Before rushing into the materials required and stepwise procedure of replacing window glass, we have an additional step of finding what kind of window and glazing you have in your window. It is very important because only based on that the tools required and the procedure I to be decided.


Types of window frames

  • Wood – Earliest in use and is one of the easiest to change glass panes if broken or cracked. Also, can take new looks easily.
  • Aluminium – Very similar to wood in terms of structure, glazing and even easier for repairs. Required least maintenance of all the three. Sometimes you might find other metal window frames.
  • Vinyl – Vinyl are the most modern-looking and most commonly found window types in houses from the last few decades. Vinyl windows usually use double glass or IGU (Insulating Glazing Unit) which are pricier than the usual.

Types of glazing

Glasses differ by the material, application of it and nature of it. Here is the most common glazing you will find in windows.

  • Plain Glass – This is your regular glass, clean and transparent.
  • Special glasses – Special glasses can be tinted, tempered or textured. With the addition of these, the glasses gain characters like low emissivity and glare control.
  • Fibre – Naturally stronger than glass and long-lasting. If you have frequent glass breaks, try using a fibreboard instead. Fibre costs a little more but lasts even longer when compared to glass. There is also a downside – it starts to get foggy with time (usually decades).
  • Insulating Glazing Unit – IGU is the two glasses held parallel by a metal or rubber cladding. Most vertical window sashes and sliders take this type of glazing. It is superior in high light transmission and low on heat transmission.

Type of sealing

Apart from the frame and glass pane, there is another important thing that holds them in place.

Usually, it is the putty. There are a lot of putties in the market. You can choose any as they don’t make much a difference. When working on modern vinyl windows you will be using vinyl stops. You can use putty in that too but won’t give you the same output as the vinyl snap bead.


missing window glass pane

DIY window glass replacement

With many windows and glazing types, don’t expect the Guide to be linear. We will run through the whole process and if the particular windowpane replacement requires extra steps you will find them branched then and there.

Let’s start with picking up the tools required. Every window glass replacement will need the following tools,

  • A new glass
  • Putty (not required for vinyl windows)
  • Glazier pins/push points (required for wooden windows only)
  • Putty knife
  • Transparent silicone (adhesive)
  • Strong gloves
  • Eye protection glasses
  • Duct tape
  • Chisel

And common tools like screwdriver and hammer.

A stepwise guide to replace glass in all types of windows:


1. Removal of damaged glass

  • Stick a duct tape in grids so that the broken glass pieces are held together.
  • Wear protective gloves and eye shield.
  • Spread cardboard or cloth on the floor for easy disposal.
  • If possible, remove the window frame, sash or the door and keep it over a table for ease of use.
  • Start loosening the window glass hold.
    •  For wood and aluminium windows use the putty knife to scrape the existing putty or use chisel and hammer combo to break it. You can use linseed oil or heat gun to loosen the existing putty.
    •  If snap beads are used make sure to snap them out carefully. There is a very good chance of breakage as they get brittle due to continuous exposure to varying temperatures.
    •  In mechanical fastening sashes, you need to remove the sash and unscrew at the corners to let the glass fall.
  • Most glasses are stuck from both sides. It is often stuck by silicone or putty. Either way, use a prying tool or a utility knife to loosen the hold.
  • Once removed safely dispose of the glass in a bin.


2. Preparation of the window

  • Scrap all the leftover of putty with a putty knife and run a vacuum if possible. Make sure the inner surface is smooth and even for the new glass to stick properly.
  • Now measure the size for the glass. Measure frame to frame in at least two different position and reduce it by 1/8 inch. The adjustment is to accommodate expansion and contraction due to climatic changes.
  • You might have to run to the glass manufacturer amidst the process. If you are well-versed get a glass cutter and a standard size glass in the beginning so that you can cut it at home.


3. Fixing the new window glass

For wood and aluminium frames,
  • Test fit the cut glass and see if it fits properly.
  • Use the silicone tube to apply an even strip of silicone on the inner wall of the window frame.
  • Place the glass and make sure it lines up on all four sides equally.
  • Use glazier pins or push pins from any brand to hold the glass in place on wooden windows. One pin every 10inches is enough. Make sure each side has at least one pin.
  • Take a ball of putty and roll it into a thin rope of ¾ inch in diameter.
  • With your finger press it in the gap nicely so that there is no place unfilled.
  • Use the putty knife to neatly shape the putty and draw out the excess.
  • If you are planning to do any paintwork on top of it wait for a few days. Ideally, the putty takes around 2 weeks to harden.


For Vinyl frame windows (fusion welded),
  • Start with applying an even strip of silicone on all four sides.
  • Place the glass and make sure it is rightly spaced.
  • Fit the vinyl beading and you are good to go.


For mechanical fastening vinyl frame windows,

The process is fairly simple. Put on frames in the right order and screw the corners.


Signing off:

It is easy to start with one and gradually go up the ladder. Like every other DIY, you might end up damaging more than what you repair. You might break the adjacent glass panes. Be careful as you work with glasses.

Time is not the limit. Take your time and get it done perfectly.


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