About PVC-U Double Glazed Windows
This is an excellent, highly insulate material, which
benefits from little or no external maintenance. It is
readily available and well tested and is usually the lowest cost option of all three materials. It is mainly seen in white but also available in Mahogany and Oak woodgrain styles. PVCu is by far the most popular material for windows and doors today.
There are many well-proven PVCu extrusions available. Problems with discoloration are virtually unheard of and most suppliers will warrant against this. The design of the windows varies from company to company. Here are a few of the main points. You may like to raise them with your supplier.
Internal or Externally glazed windows
Most PVCu systems will now give you this option. As a generalisation Internally beaded windows (where the glass is held in from the inside) are considered more secure and burglar resistant. That said there are a lot of satisfactory externally beaded PVCu systems about – many of which feature either internal wedge gaskets or a “double sided” tape which holds the external bead firmly in place.
You should investigate this particular issue with your supplier.
Thickness of PVCu walling?
Most PVCu systems for window and door construction are “multi-walled” with internal reinforcement by means of either Aluminium or Galvanised Steel box section. Wall thickness can vary from system to system – most are around 3 – 3.5 mm thickness. Generally speaking the “thicker” the walling – the stronger the section. Ask your supplier for an example section and enquire if the frames are fully reinforced. Note also that the greater the number of internal walls – the greater the strength.
Depth or thickness of frame
Actual depth of frame extrusion varies from as low as 50 mm to a number at 70 mm and above. Most are in the 60 – 65 mm region. Clearly this does have an effect on the structural strength of your replacement window or door. This is especially worth bearing in mind when comparing prices. It would not for instance be fair to compare the price of a conservatory built using a 55 mm depth of frame with a window made using 70 mm depth of frame.
We bring the points above to your attention purely to give you a feel for the sort of questions you should ask a potential supplier. The above is by no means the whole story, and there will be varying arguments one way and the other.
Here is a short list of PVCu systems companies supplying extrusion for the manufacture of PVCu windows and doors in the UK. These include Rehau, Veka, Spectus and Synseal.
For some, however, PVCu lacks authenticity when it comes to the more traditional
designs. It is not acceptable to planners for use on listed buildings and not popular with planners in conservation areas.
Coloured Frame Options
What colour do you want? You name it and today you can almost certainly get it. Standard colours for PVCu and aluminium are white, whilst for hardwood it is a natural stain option such as mahogany, walnut or light oak. You can, however, have hardwood already primed in green, cream and teak plus a whole host of options to your specification. PVCu in mahogany woodgrain and cherry oak woodgrain styles is also increasingly popular. Additionally, both PVCu and aluminium can be specially coloured in red, blue, green, black and orange! (and that’s just a few of the options!)
The above only really touches the surface on some of the options available. Your supplier will be pleased to give you a more detailed specification.
This article is about PVC-U Windows (also referred to as upvc, pvcu and pvc windows). Other materials used for windows include Aluminium and Timber / Hardwood
For more information on Double Glazed replacement windows visit Windows Today http://www.windowstoday.co.uk/
In this section we introduce you to some very important but often overlooked issues when choosing window designs. Regrettably we find that quite often some aspects of window design are not discussed at the buying stage. These aspects can often turn out to be very important to the buyer.
One such issue is “equal sight lines”
Unequal Sight Lines Equal Sight Lines
When manufacturing most modern replacement windows it is normal for there to be smaller areas of glass wherever there are openings (sashes) fitted. Where the frames are fixed the glass area will be larger. This “unequal” site line is quite normal and acceptable to most people.
However on a lot of older properties (and indeed some newer ones) it was more common to have an equal sight line. (i.e. you would not be able to tell from the outside which windows opened and which did not.) Fitting “dummy sashes” or “dummy openers” into the frames created this “equal” sight line.
As you will see from the photographs above the windows can have a considerably different appearance dependant on whether or not they have equal sight lines.
Equal sight lines are not for everybody – indeed some will not like the overall “bulkier” appearance. However there is no doubt that for some types of property this will be a “better bet”. It is also a very good alternative with Georgian and Leaded Light window designs as it allows you to have rectangles / squares that are more equal in size.
Having equal site lines adds to the overall cost of your replacement windows and for this reason many people do not favour this approach. That said — it is still a worthwhile consideration in our opinion.
Another possible alternative is to consider having “vertical equal sight lines”. With this approach fixed windows are always above fixed windows and opening windows are always above opening windows. Ask you suppliers for more information on this if this is unclear to you.
Another design issue that is often overlooked is whether to use black gaskets or white gaskets on your white PVCu windows.
Black coloured gaskets are the norm with most companies and are widely fitted. In the past white gaskets had not been favoured as it was not always possible to get a “matching” white and it was not also possible to offer a “colour fast”
guarantee. This has now changed and more and more companies now offer both alternatives.
We feel white gaskets are a good alternative – especially on “panelled” doors.
This photograph shows a panelled door design with black gasket. It would have looked better with a white gasket.
An alternative to white gaskets are “low profile” black gaskets which are very slim and less obtrusive.
One disadvantage of white gaskets reported by some people is that the gasket will often appear grubby and show up the dust/dirt. This may be an important consideration is you live close to a major road network etc. (Or don’t fancy cleaning too often!)
Whatever your choice we do especially recommend white gaskets on white PVCu panelled doors.
Consider your Neighbours
When replacing windows it is sometimes worth considering the effect of your changes on the overall appearance of the street or road where you live.
For instance if you and your neighbour both agree on a style for your windows the overall effect can be considerably better if you both agree to use similar designs. It doesn’t matter if you both use the same company or even have the work done at the same time.
Sometimes using “conflicting” styles or designs “side by side” will spoil the appearance of the neighbourhood. As can be seen in the photograph below using similar designs on both of these porches has added to the visual appearance for these two neighbours.