How to Tell a Good uPVC Window From a Bad One
What Makes a Good uPVC Window?
In today's market, you would think it would be easy to spot the differences between a good uPVC window and a bad one. For example, in the UK and Ireland, windows now come with a cert. This is an energy rating to tell you how good the window is at keeping the heat in. The rating starts at A being the best and B being next in line, and so on.
Problem sorted! Just look at the cert and you must be getting the best window. WRONG!
What if you go to a company that has been around for a good while and has an A-rated cert on their window. You are still not guaranteed.
So how do you tell then? With a little knowledge, that's how.
How a Window Gets an A Rating:
All that is needed is to change the reinforcement from steel or aluminum to a warmer reinforcement like carbon. This will reduce heat loss through the frame of the window. Then you must upgrade the double glazing so it also has a warm edge spacer bar and Low-E glass plus it must also be gas filled. Argon is the most common gas which is used. But with some window systems, this still is not good enough, and they must upgrade the gas to Krypton gas.
So now you know how the window gets an A-rated cert and is good at keeping the heat in. (What more do you need to know?)
Below is a list of a few other things you might find useful to know about uPVC windows.
uPVC Section: This is the plastic that is used to make your windows. Make sure there is at least a ten-year or more guarantee with the system. This should cover it from discolouring and warping.
Glass: Check what guarantee is with your double glazing. A lot of the older double glazing came with a seven-year warranty. But Most of the newer double glazing will come with a fifteen year or more warranty.
Locking System: There are many types of locking systems out there. Some window companies will just use the cheapest one on the market unless you ask for a better system. The most common one is the Espag locking system. But if you want a bit more security, then a shoot-bolt system is a better option.
Bead System: Is the bead system external or internal? (Internal means the glass can only be taken out from the inside.)
Fully Welded or Mechanical Joints: All uPVC windows would have the four corners of the frame and sash welded. But the mullions and transoms can be welded or mechanical. Mechanical mostly comes with older systems, but it is still around today. It is a quicker way to make windows; the main fault with this system is in some cases if the transoms or mullions shrinks even by half a millimetre, it can let a draught in.
Window Handles: There are loads of different types of handles being used. Some will only last six months to a year depending on how much use it gets. Other are designed to last five years or more. How do you tell one from another? That is the problem—it is very hard. The best thing to do is to make sure you have a two-year guarantee with all moving parts on the window. Plus, find out what their policy is on coming out to do repairs.
Hinges: These are just like the handle there are so many different types you don't know if they are good or bad until they start to fall apart. Again make sure there is a two-year warranty on all moving parts. If possible check with some of their older customers to see how they got on.
Screws Holding on the Hinges: This may not seem like much, but you don't want to open your window in a year's time and see a load of rust there, or worst have your sash fall out because the screws holding the sash in have rusted away. A lot of window companies will use zinc-coated screws, and on the bottom of a side-hung sash, these will be changed to stainless steel screws. But it is better if you had all stainless screws and if you live near the sea it is a must that you have all stainless steel screws.
How do you tell if they are stainless steel screws? Get a magnet, and if it sticks to the screw then it is not stainless steel. Magnets will not stick to stainless steel.
Interlockers: These are two-angle uPVC blocks which help the sash close properly and keeps it tight against the seal. Plus they also give your window better security. All window systems have these; the only reason they might not be on a window is because the fabricator was too lazy or just forgot. It happens and you would be amazed at how many windows these are left off.
So if you are about to invest in new windows, don't be afraid to ask the window company about any of the things you read here. If it looks like you know a bit about windows, you will find that you will get a better job done as they know you will be checking everything.
- What energy rating is the window (A-B-C-D)?
- Warrantees. There are three different ones, so ask about all three. (Section, Double Glazing, Moving Parts.)
- Internal or External glazed? (Internal is better for security.)
- Screws holding on hinges? (Stainless steel are best.)
- Locking system? (Shoot-bolt is one of the best security options.)
- Inter-lockers? (Make sure they are fitted.)
If you have any questions or comments, please feel free to post them in the comment box below.
Did you find this information helpful?
This article is accurate and true to the best of the author’s knowledge. Content is for informational or entertainment purposes only and does not substitute for personal counsel or professional advice in business, financial, legal, or technical matters.
Questions & Answers
Is the thickness of glass important in uPVC windows?
Most double glazing today is 24mm or 28mm thick. With a Low-E glass on the inside pane. A lot has gone up to 32mm thickness made with 4mm thick glass. The overall thickness of these units will not make any different's to your window. Once they all have the Low-E glass.
If a double glazed unit goes over a certain size, the glass will go up to a 6mm glass, but the over all thickness will stay the same. They just reduce the spacer bar thickness.
By having your unit made with 6mm glass instead of 4mm glass can make a difference. The 6mm is more secure plus it is better at keeping noise out. The insulating factor will go up by a small bit, but not by anything you will notice in your heating bill.
BUT what makes the differences to the insulating is what type of gas they fill the unit with. So if your unit is filled with an argon gas than the thicker the unit, the better it is. As you will get more gas in. Which means more insulating.
Note: Low-e glass is used as standard these days. But with some suppliers, you will have to pay extra for the argon gas. Plus there are a few different types of gas being used which perform better than the argon gas. But you will have to pay extra again for this.
Below is a few different types of unit makeups to give you an idea.
- 28mm thick unit made with 4mm glass inside pane is Low-E (used as a standard today)
- 28mm thick unit made with 6mm glass inside pane is low-E (extra secure plus keeps out more noise)
-28mm thick units filled with gas (extra insulating)
-32mm triple glazed unit made with 4mm glass and gas-filled (good at keeping noise out plus very good insulating factor)Helpful 10
In respect of the frame section of a window, what does good PVC section look like and what does the middle of the road section look like?
On the inside of the section, a good one should have three to four different chambers inside. One is to take the reinforcement, and the others are to stop the cold traveling through.
A bad one will only have two chambers inside which will allow more cold get through.
PLUS a good section will come with a warranty of at least fifteen years that it will hold its color and shape.
A bad PVC section will only come with a seven-year or less.Helpful 7
You mention beading. Would external beading not allow burglars easy access? Hence internal beading being offered? Am I oversimplifying?
Most new windows come with internal beading, and the windows with external beading come with a wedge system to push glass outwards to stop beads been taken out. Or they might have a security tape to hold glass in. But in some of the older and cheaper systems if the wrong gasket is used you can still get the beads out from the outside. Plus if a cheap security tape is used then it will just lose its grip in a few years time. But the internal Bead system has none of these problems. In fact, the only way to get the glass out is from the inside even in the cheapest system.Helpful 6
Hello. How thick should the PVC be on the exterior of the home?
Most PVC profile systems are now 70mm front to back, and the walls would be around 3mm thick and made up of 5 chambers or more. It's the different chambers that keep the heat in on a PVC windowHelpful 5
Should the lock-side coupling of a UPVC door frame with sidelights on both sides be reinforced with plastic or steel?
PVC-covered steel is typically used to reinforce UPVC door frames. Otherwise, your door will be quite wobbly when closing. But if you are going for a very high U-value, you should use a carbon reinforcement. I have never seen plastic used as it's just not rigid enough to stop the door from wobbling when closing.Helpful 4
© 2012 Martin