Get a Bifold Quote Download Brochure

Although we hope you do not have any issues with your glass we would like to take the opportunity to outline what to expect from your glass and HBD’s criteria for visual defects in glass and their acceptability. The page below will cover the following; double glazed units consisting of toughened, laminate or standard glass. Including any coatings or tints on or within the glass.

With all glazing supplied a certain amount of visual distortion is acceptable in the manufacturing process. There is also an acceptable level of defects that can be evident but occur naturally in this process.

We always class damaged glass as unacceptable, it may be installed temporarily as a necessity to keep your home weather proofed but it will always be replaced when a new glass unit has been ordered and delivered.

Our objective at HBD Systems if to supply and install glass as free as possible of defects caused in manufacture. However you should know what to expect from your glass and accept minor imperfections/ manufacturing visual distortions provided they fall within the scope of he following definitions and acceptance criteria.

There will however be a distinction between large pane glass units and what would be considered ‘standard glass sizes’. A large pane glass unit would be any pane having square meterage of 2.5 and over. In the case of large glass panels the end user/client must be aware that the defect threshold will increase as the glass area percentage becomes higher.


Visual Distortions


Roller wave

Roller wave is a common type of visual distortion that may be visible in toughened glass. It is caused during the toughening process when the heated and slightly molten glass is passed over large rollers while it is cooled. As a result the glass may have a slightly waved finish to the surface.

This does not affect the strength or durability of the toughened glass and is only visually detectable under certain circumstances.

As a rule, the visual appearance of roller wave in glazing is not classed as a glass defect.




Contact Us

You are welcome to drop into our Hertfordshire showroom and speak to a member of staff at your own convenience or call us on 01727 845600.