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PVCu or uPVC – What’s the Difference?

If you’ve been shopping for exterior doors or windows recently, you might have come across two similar terms: PVCu and uPVC, and wondered what the difference is between them.

Let’s cut to the chase: there is none. Any time you see the term ‘uPVC’, you can mentally substitute the term ‘PVCu’ (and vice-versa). So, why are there two terms for the same thing?

Let’s take a look.

So what is uPVC (or PVCu)?

Let’s rattle through a quick uPVC definition. The acronym stands for unplasticised Poly Vinyl Chloride. It’s the same stuff used to make faux-leather clothing, inflatables, and electric cable insulation, except that it’s not had a plasticising agent added to it. This agent is what makes the material flexible. Without it, uPVC is tough and rigid, and at the same time waterproof and glossy. It’s the perfect material, in other words, from which to build a window frame.

What uPVC means in practice is chunky white window frames. The material is recyclable, and cheaper to manufacture than aluminium. When uPVC was first introduced in the 1980s, it had another advantage over aluminium – it didn’t conduct heat as easily (aluminium windows have since been designed with effective thermal breaks in the centre, meaning this isn’t such a problem).

uPVC enjoys a considerable advantage over timber in that it doesn’t need to be finished and maintained in the same way – the topmost layer is inherently glossy, which means that stains and moisture will slip from the surface. As such, you needn’t worry about choosing paints or adding additional hardware.

It’s for these reasons that uPVC is to be found on so many British homes.

Why Do We Use the Term PVCu?

uPVC first entered Britain thanks to German manufacturers, and, as a result of the double-glazing boom of the era, it ended up becoming something of a marketing buzzword. Everyone, it seemed, wanted their house equipped with energy-efficient uPVC windows.

So, if uPVC was a perfectly good term, why did ‘PVCu’ come about? The answer comes from mainland Europe, where sentences are often formed with the adjective after the noun (just think of Fédération Internationale de Football Association). In the 1980s, it was decided that British manufacturers should use the same term as their European counterparts in order to avoid confusion. And yet, making this transition proved rather difficult – as getting an entire industry to change its habits often is. We’re thus still using the same term decades later, and there’s no indication of this changing anytime soon!

As a side benefit, ‘PVCu’ might appeal to those of us who appreciate consistent capitalisation. ‘uPVC’ at the start of a sentence just doesn’t look quite right.

What’s the Correct Term – uPVC or PVCu?

Some may insist that one term or the other is correct, but there is no practical difference between the two. Whichever you prefer to use, you’ll be understood by our team – and the benefits of the material remain the same!

Looking to replace your windows? Start your shop for our full range here.

Woman cleaning window

How to Whiten Yellowed uPVC Windows

Arguably the most popular material for modern windows is unplasticised Poly-Vinyl-Chloride, or uPVC. It’s robust, inexpensive, and lasts for years with minimal maintenance. To keep yours looking spotless, you only need give it the occasional wipe down with a damp cloth.

Over time, however, certain sorts of uPVC are prone to discolouration. Those brilliant white frames, if exposed to the elements for long enough, will turn an unsightly shade of yellow. In this article, we’ll take a look at the problem, why it happens, and see whether there’s anything to be done once your uPVC has gone yellow.

What Causes uPVC to Turn Yellow?

There are several things which can cause uPVC to turn yellow, but the likeliest culprit is exposure to UV light. You might notice that your windows aren’t so yellow in places where the sunlight is restricted (your south-facing windows, for example, might be most affected).

One of the major advantages of uPVC is that it’s recyclable, and therefore environmentally friendly. But it’s for this reason that not all uPVC windows are created equally. If your window has been made using extra plasticizing agents and pigments, then it might be more vulnerable to discolouration.

How Not to Whiten Yellowed uPVC Windows

Having identified the problem, we’re left with the question of how to make yellow uPVC white again. You might be tempted by several common cleaners, some of which are to be avoided at all costs. Two offenders in particular stand out:

Bleach might seem a sensible option for cleaning yellowed uPVC. It turns things white, doesn’t it? Why shouldn’t it do the same to your window frames?

Unfortunately, it’s not that simple; bleach will react with the PVC and turn it a disastrous shade of brown. If you use it, even in diluted form, you can expect a total catastrophe that can only be fixed by replacing the entire window.

Sandpaper might also seem a sensible option. If the top layer is discoloured, then surely all we need to do is scrape it away to reveal the whiteness beneath. Again, this is a misunderstanding of how uPVC works – the topmost, glossy surface is created as the plastic is manufactured – the interior of the material is quite different. It’s dull, and won’t repel water or stains in the same way. If you sand your uPVC window, you will ruin it.

How Do You Clean Yellow uPVC Windows?

Depending on the nature of the staining, you might have some luck with more gentle cleaning solutions. Baby wipes have been known to lift away some stains, and make a good first point of call if you have access to them. Household cleaners like CiF should be regarded with some caution; be sure to check the bottle doesn’t contain any bleach.

You can also find some specially-formulated uPVC window cleaner on the market, which may restore new life to ailing windows. Even if you don’t experience stellar results, you can at least be sure that you aren’t going to do any harm!

Looking to replace your windows? Start your shop for our full range here.

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