What exactly is double glazing? Double glazing is the name for windows that are made up of two layers of glass or other transparent material with a space of air between them. This dead air space acts as an excellent insulator. It keeps heat in the home during the winter whilst keeping the home cool in the summer. Double glazing comes in several widths, although 24mm and 28mm are the most common.

Double glazing settings are made from PVCu which is a type of plastic which stands for Poly Vinyl Chloride Un-plasticised. PVCu is an adequate material to be used in this way as it has to be very resilient. We can see why it is the chosen material by looking at its properties - does not rot or biologically decompose; low maintenance due to weather resistant; retains shape within changes of the seasons; and it can be reshaped at a very high temperature so it is therefore recyclable.

Double glazed windows have a huge variety in quality, and therefore price. This is due to there having been many improvements since it was first used in the window industry. Advances in technology have resulted in positive as well as negative aspects for products. On the positive side, the construction such as the welding of the joints is highly efficient; there are solid areas that house steel reinforcement; and there are improved glass coatings. However, on the negative side, there is the beginning of and consistent use of recycled PVCu and use of cheap and dubious DIY fittings that have made double-glazing available for just about anyone, no matter their skill or experience, which results in poor installation and product and cowboy builders.

Recycled PVCu may look perfectly fine on the sample, but it does not retain the hard shiny coating in the long run. It is susceptible to grime and dirt which discolours it. Once this happens, you can not clean it or repaint it. You will be left with worn-out looking windows.

The space between the two panes of the window also vary drastically. The width and what it is filled with affect what benefits you want from your windows. There is a compromise between sound insulation and heat insulation. If you ideally want excellent sound insulation if you live near a busy road for example, then the heat insulation will be compromised slightly because of the way it is constructed. Secondary glazing would be the best for sound insulation because this gives a deeper gap in the space between the panes to protect from noise, but this then leaves a larger space for heat to escape. The optimum distance for a double glazed sealed unit is 20mm between the inside surfaces of two sheets of 4mm glass.

The Signs of a Good Professional Salesman

The salesman should visit your building to measure your windows and discuss your requirements. The salesman should present a sample and demonstrate their wares enthusiastically, as this is a sign of a knowledgeable salesman. The most important aspect is that you need to see what you are paying for! Finance should then be discussed and a price should be calculated for you. This is everything that you should expect from a company. A good salesman will want to make sure you are confident that you are receiving excellent service and that you are happy with the wares and price. You would not get the above mentioned service if you only wanted a quote without the ‘hassle’ of a salesman visiting – you would not be seeing what you are paying for. If you did your research this way, you would be bringing yourself trouble because a simple quote will not be very accurate and you will not be 100% aware of what exactly is included in the price and therefore will be left wanting.

A good professional company will employ only the best salesmen who will be concerned with giving their customers the best service and will explain how they will do their business with you in detail, for example; "Experienced John Williams’ professionals manage each project from concept to completion. We’ll even take care of planning permission or building regulations approval, if required. When we install our products we rely solely on our own highly skilled professionals to do the work. They are trained to be punctual, courteous, considerate and careful with your possessions, and complete the work without delay, with the minimum fuss and disruption." (http://www.johnwilliams.co.uk/)

For perfectly fitting and secure windows they should be manufactured to a fine standard. This is quite expensive and may take a little longer to fit, but the alternative is not worth thinking about. Your windows may be held in place with nothing more than some DIY ‘expanding foam’ covered by a strip of silicone. The whole unit can then be removed from the outside with a crow bar or a shovel. Additionally found with cheaper services is, if loose fitting units are bolted in place, there is a risk that the bolts may be over-tightened, damaging the frame and compromising the effectiveness of the sealed unit. The construction should be explained to you and be executed to the upmost excellence, such as "Computer-aided design, state-of-the-art production processes and rigorous quality control ensure precision at every stage." which is found at John Williams Home Improvements.

Conclusion of Double Glazing

Main Advantages: Secure, energy efficient, low maintenance, adds value to your home.

Main Disadvantages: Beware dubious materials and fitters. They will cause more harm than good – and the resulting windows will offer none of the advantages listed above.