Broken double glazed window?

Updated on August 6, 2022

Need to replace glass in one double glazed window.

Would I be right in saying all I need to do is take out rubber beading round glass takeing care it does not fall out?!

10 Answers

  • There are basically two types of windows, internal and external glazing.

    Let me explain the difference. When your windows were installed, the fitter would have either installed the glass sealed units standing inside your house, or standing on the outside. Either way the principle is the same.

    First you need to look at the glazing beads, these are the white trims that hold the glass in place, they are mitred in the corners. You will need to remove these to gain access to the sealed unit, generally they are very tight, but a good starting point is in the corner.

    Work something small that has a flat blade into the slight gap between the window frame and the glazing bead/trim.

    Over the years there have been many window companies producing sealed units, unfortunately the sealed units will vary in thickness,

    Here are some examples 4mm piece of glass 10mm spacer bar then 4mm piece of glass

    4mm glass 12mm spacer bar 4mm glass

    4mm glass 16mm spacer bar 4mm glass

    4mm galss 20mm spacer bar 4mm glass

    You would need to measure the thickness of the sealed unit once you have managed to get it out, in order to ensure you purchase the correct one.

    If you get it wrong, the beads will not fit properly and your window will leak.

    Before you start the project, have a look very closely at the window, some have a rubber gasket around the glass that needs to be removed, prior to the glazing bead removal, you can remove the gasket by digging in corner with a flat blade, once you get a bit out, it will be easy to pull it out, that will now relieve the pressure off the glazing beads, and they will be easy to remove.

    Although this is a job you can do yourself, it’s more detailed than you might think, most glazing beads require a bit of a knack to get them back in.

    Some sealed units have gaskets and glazing beads/trims, others have double sided sticky tape, you remove the glazing beads, and the glass will not come out, because around the edge of the glass is a double sided sticky tape, you need to cut the glass away from the frame using a utility knife/stanley knife, then you have the hassle of trying to obtain new tape, and the hassle of making sure the sealed unit you order is the correct size and so on.

    I would suggest that you actually call a local companyto give an estimate to replace the sealed unit, a professional will just take a look at the project and know instantly what type of system you have without taking anything apart, a couple of days later, or maybe the same day, he would return to replace the unit.

    Your sealed unit will be made to order, so if you broke the glass trying to get it out, now you have another problem on your hands.

    I used to have my own window and door installation business prior to moving to America. Generally speaking an average sized sealed unit would cost you about 70/100 pounds to replace by a professional.

    The cost for you to replace the unit would be about 40 pounds plus the agrovation. All window companies buy sealed units for trade price, about four pounds a square foot for clear glass, and about 40 pounds a square foot if you have Georgian bars.

    It would take a professional about 10 mins to do the job, maybe a bit longer if you made him a cup of tea LOL.

    I honestly believe this project would be better left for the experts, having a broken window is no fun especially during winter months.

    I hope this information shall be of benefit to you, if you decide to go ahead and do the job yourself, here is my email address, I shall be happy to give you a step by step guide, once i know the type of window that you may have installed.

    Also bear in mind, if the sealed unit is 800mm or less from ground level, it will need to be toughned glass, which is more expensive than regular.

    [email protected]

    Good luck


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    Broken double glazed window?

    Need to replace glass in one double glazed window.

    Would I be right in saying all I need to do is take out rubber beading round glass takeing care it does not fall out?!

  • Most manufacturers will use a sealant to seal around the glass as well as a glazing stop. I use a knife designed for cutting through the sealant, call it a butter knife in window speak. It is not as easy as it seems to remove and install a new piece of insulated glass. Call a glass company, will have the know how and the right tools.

  • If you are talking about a window with 2 panes of glass in it Then no it is not that simple.During the manufacturing process the air is removed from between the sheets of glass and inert gas is injected to stop condensation from forming between the sheets.Once the seal is broken the gas is gone.Even if you do replace the glass you’ll get condensation build up.

  • well your issue isn’t a simple one. If your windows are newer, just call the manufacturer and tell them the window size and they should be able to make you a replacement window. This happened to me in my new home and the information you need will be printed on a sticker somewhere on the outside of the actual window. You will need to slide the window open and pull it in towards you to find the sticker. My mfger had no problem in replacing my window. they sent it to me and i was able to install it myself.

    If your windows are older and maybe have a wooden frame, take the window out and take it to a window or glass place and ask them to replace the glass. It won’t cost as much to replace just the glass as it will to replace the entire window.

    Good luck to you.

  • Yes and there should be a plastic seal that clips in on the outside as well which you can lever off carefully with a flat screw driver. If i can find a picture i will get back to you.

    Cant find a picture but if your windows are as old as ours the seal is black on the inside and out. if they are newer they will be white.

  • you forgot to say what the window is made of ..sound like its the old plastic ones remove black beading ..making note of where each bit come from (some are one peice).. then you remove front beads ..replace unit ..refit front beads ..then refit the black beads

  • There will be a spring retainer around the outside of the window, if you use a large flat screw driver you should be able to pry it out.


  • lift the glass out of the frame and put a new sealed unit in.

  • Good for you.

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