This is a Guide on how to replace double glazing in a PVC window. Over time your double glazing might fog up or just get broken.
If you have already had to replace double glazing before , than you already know it is not cheap and can be a lot of hassle trying to get someone to call, specially if it’s only a small double glazed unit. But as you will now learn it don’t have to be a big job and can be done in just a short time.
If you are going to replace the double glazing yourself than you will need three measurement. It may be best to take the old glass out and measure that before you order. This way at least you will know that you can take the double glazing out of your PVC window and your measurements will be right when you go to order the new double glazing for your PVC window
Step 1 : Which type of glazing system is your PVC window
First thing you need to know is what type of glazing system your window has. Most of the newer windows will have what’s called an internal beaded system. This means the glass can only be taken out from the inside. But it is the fastest and easiest system to change double glazing. The older system is external beaded system this means the glass must be replaced from the outside.
How you tell the different’s is just look for the beading which holds the double glazing in. The beading is about 20mm in size and will go right around the window. If its on the inside than you have internal glazing
Step 2 : Take out beading
Internal beaded system
You will need a knife or flat screwdriver to prise out the beading. Just get the knife and force it in between the window frame and the beading. Once you get it started you will find it comes out quite easy. Just watch for when you take out the last beading as the glass can now fall out.
Video below shows glass been taken out in a internal glazed pvc window
External beaded system
The first thing you do is on the inside of the window. Take out the rubber gasket that is between the glass and the window frame. This gasket is pushing the glass outwards so that the beading on the outside can not be taken out. Once you have the gasket out, go to the outside and take the beading out. You will find that the beading should be quite loose and come out easy. If the beading is still not loose it could mean the double glazing is just stuck to the beading. If this is the case just push the double glazing inwards until it becomes unstuck. Just be watch out that you don’t break the glass while pushing it.
Below is a video showing glass been take out on a External glazed window
Step 3 : Measure the double glazing
Now that all the beading is out the double glazing should just fall out for you. To measure the double glazing you will need three measurements. Height – width and thickness. Once you have these three measurements you are now ready to order your double glazing
Below is a video showing how to measure your Double Glazed unit.
If you already know the thickness of the double glazed unit, than you don’t need to take out old glass to measure for a new one. You can just measure from the edge of the beading to the edge of the beading on the other side. Than minus 10mm from your measurement this is to allow for glass to fit in without been stuck against the sides. It is the same for internal & external pvc window systems
Step 4 : Putting in the new double glazing
Once you have the new double glazing there is only one thing to watch out for when putting in the new glass. On the bottom of the window were the glass sits there should be glass packers. These are to stop the window from sitting on the window frame. Sometimes when you take out the old glass they are stuck to the bottom of it. So just make sure you take them of and put them under the new double glazed unit. Also if the double glazed unit that you are replacing in an opening than there maybe more glass packers right around the glass. If this is the case just put these back around the new double glazing. They are there to stop movement when you open and close your window. Without them your window sash can sag down and start catching on the bottom of the window frame on a side opening window.
Tip 1 : If you are changing your glass because it got broke from a football or something. Than maybe it might be worth your while to upgrade your glass to a safety glass. This way a football will just bounce of it and won’t do any damage.
Tip 2 : if the glass you are replacing is close to a busy road or some place that has a lot of noise. It might be worth your while to upgrade it to triple glazing. Not only will it be better at keeping heat in, but it cuts out a lot more noise.
Tip 3 : if your window suffers from condensation make sure your new double glazed unit has warm edge spacer bar and low E glass. This will stop most of the condensation if not all. The spacer bar is the bar which separates the two panes of glass. Most of the older double glazing just used an Aluminium bar but because this is a metal it can cause some condensation.
Some glass facts
- The measurement to measure how good double glazing is at keeping heat in is called a U-value. The lower the U-value the better it is.
4mm single glazed U-value = 4.6
20mm standard double glazing U-value = 2.6
28mm double glazing with low-e glass U-value = 1.5
28mm double glazing low-e & gas filled U-value = 1.3
32mm triple glazed low-e & gas filled U-value = 0.8
Note : U-values above are a guide only, as they may change depending on which company makes them. Some companies can get better results than others with there low-e glass. But there would not be a huge different’s
- Low-e is a coating that goes onto the glass, which reflects the heat back into the room. This coating can also keep some of the suns heat out. But it will also keep out most of the suns uv rays. These are the rays that will discolour furniture.
- Self cleaning glass is available. But it needs a certain amount of sun & rain in a month before it will work.
- Glass has been invented that can produce electricity it works the same as a solar panel.