Sliding patio doors, introduced over 50 years ago, provided home-owners with an inexpensive way to brighten living rooms and create an additional access to the garden.
Over the decades, improvements have been made to the thermal qualities, the types of glass used and the way the panels slide. Sliding patio doors can be constructed from soft or hard woods, metal, alloys and PVC. The final choice of material may depend on a number of factors, such as price and compatibility, and openings wider than 8ft may not be easily accommodated.
Because sliding panels need to be parked somewhere, the width of at least one panel restricted access. On a two-groove system, only one door width provided an opening gap on a two or three panel system, restricting accessibility by 50% or 76% of the aperture.
It was only comparatively recently that a new concept of hinging the panels to fold, concertina-style, in order to create more access. Using stronger materials, a number of folding doors could open for nearer 100% access and be installed to fill apertures in excess of 6m (20ft).
More recently still, the sliding panel system has returned, reborn!
The latest innovation, introduced this summer, is for sliding doors to turn at the end of the runners and stack against the side walls, thus enabling access through almost the whole aperture.
Like the original sliding patio doors, the frames are narrow and made of metal. Unlike their predecessors, however, the materials used have been improved in many ways: powder-coated thermally broken aluminum frames are not prone to rust and are bad conductors (this is a good thing – the hot or cold outside temperatures have little effect on the temperature of the frame); K-glass or similar virtually unbreakable glass is used and adheres to today’s strict insulation standards; finally, the sliding mechanisms are unrecognisable from the tongue-and-groove methods of years ago, therefore the doors slide smoothly without sticking.
Theoretically, there is virtually no limit to the width of an opening that can accommodate this style of sliding-stacking patio door.
The most popular colour choice for powder-coated frames is natural white but other popular colours are grey, sepia brown, green, blue, silver and bronze (the frames can be manufactured in any RAL colour). It is also possible to opt for Venetian blinds to be encased inside the double-glazed units.
With the evolution of sliding-stacking doors, the humble patio doors have come of age.