Before fitting new PVCu windows at any property, they always undergo a thorough test and check at our factory, in addition to the installation team checking them again after they have been fitted.

How to do a professional check
In order to ensure accuracy when checking we always try to stand in the room no less than 2 metres away from the double glazing unit and look directly through them.

Key things to remember are:

• Check the window in natural daylight but not directly towards the sun, and with no visible moisture on the surface of the glass.

• Exclude a 50mm wide band around the edge of the glass.

• View the glass at a 90° angle to the window.

By doing this you can check for blemishes such as bubbles or blisters, fine scratches (more than 25mm long) or particles. If any of these elements are found, but are not obtrusive or bunched then the window is fit for purpose.

 The obtrusiveness of blemishes is judged by looking through the glass, not at it, in natural light. As double glazing is a processed glass, small blemishes can be expected.

However if there are smears, fingerprints, or dirt on the cavity faces of the glass the window will be deemed unacceptable. In the majority of cases blemishes such as these will be found before the windows leave our factory and a new, acceptable unit will be installed instead.

Special Glass
It is also useful to be aware of potential visual effects that can appear on special glasses, but are not a fault. These include:

• Toughened Glass - visual distortions may show which are accentuated by reflections in double glazing. These do not affect the performance of the glass.

• Laminated Glass - this may have a few more blemishes due to it being made of several layers.

• Low Emissivity Coating - this can produce transient visual effects, which in some lighting conditions may look like a transparent film or produce a haze to the surface.

 In addition you may experience double reflections - caused by multiple surface reflections in double glazing - or Brewster’s Fringes - a rainbow effect produced by glass refraction of light due to high quality flat glass sheets being placed parallel to each other.

For more information on the range of windows we manufacture and install click here.