Double Glazing

Double glazing is accepted as being the standard fitting on modern window replacements. In the past replacement windows were of a single sheet of glass, double glazing as the name implies, uses two panes of glass. The two panes of glass are installed into a sash or frame that has a gap between them creating what is known as a sealed unit. They are kept separated by a spacer bar normally aluminium filled with silica balls which extract moisture from the air.

The benefits are numerous for double glazing installations versus single glazing which is why all window replacements undertaken are now double glazed. Double-glazing offers a level of safety and security that traditional windows cannot match. Single pane windows are as the name suggests are made of a single sheet of standard glass. The, heat loss through this is more than twice that of double glazing.

Due to the regulations set out by the Glass and Glazing Federation most double glazed units will come with laminated or toughened glass reducing the chance of shattering. Another benefit of double glazing is if one pane is damaged it is not carried through to the second pane therefore offering a much higher degree of safety and security. Our vetted network members offer high security window frames and locking systems which will make it more difficult for intruders to gain entry to your home.

Modern low-emissivity glass (Low-E) such as Pilkington K glass will allow the sun’s heat and light to pass through the glass into your home to aid heating it as well as preventing the heat from your central heating leaving the room. All our network members offer double glazing units that have very effective draught proofing systems. Not only will this keep your house warmer, you will save money on your heating bills. Your home can lose up to 25% of their heat through the windows when you have single pane glazing fitted, but the double glazing prevents much of the heat escaping thus saving you money on your heating bill. It has the added bonuses of being more environmentally friendly reducing your carbon foot print as your home will lose less heat, and also reduces outside noise levels

The gap between the 2 panes in double glazing is normally between 12mm and 20mm. There is no real difference between the 12mm and 20mm air gap in the heat loss performance The original double glazed units had a 6mm gap As things advanced a few manufacturers moved up to an 8mm air gap (and salesman used this as a unique selling point). A 12mm air gap followed, and really became the norm, it was proven to perform a lot better than the early 6mm air gap, As the gap gets wider it was found that the insulating properties did not increase exponentially because a critical thickness of gap was reached. To increase the insulation properties an inert gas such as Argon can be used as this gas has a lower convection than oxygen and nitrogen found in the air.

The insulation value of double glazing is measured the value U, standing for the measurement of heat transference through the glass. U is worked out by assessing the unit gap size, whether it has air or argon, and whether it has a Low E rating like Pilkington K glass.

In terms of maintenance PVC double glazing offers the lowest level of maintenance. Hardwood double glazing will require regular treatment to maintain their durability and aesthetic appearance. If you do not like the appearance of UPVC double Glazing and feel the need to have wood, choose Softwood double glazing for economic reasons. Modern UPVC double glazing has advanced in recent years and come with hardwood effect frames. At a distance you will be hard pressed to notice the difference. Appearance over maintenance will be the main consideration for most people.