There are several claims that bi folding doors "bring the outdoors inside" but there is more to be gained by extending your living space - cooking outside and dining al fresco.
Retractable doors (doors that will fully open to enable use of the maximum width) include the following styles:
· Folding sliding, concertina style doors,
· sliding 'pocket' doors and
· multi panel slide and pivot door sets
These will form a significant part of a wall, making indoor and outdoor living areas virtually seamless.
A weather-proof low cill can often be installed for ease of accessibility retractable glass wall by young and old plus wheel-based items - walking aids, strollers, wheel-chairs and hostess trolleys.
The difference between the different types of patio doors is more noticeable when closed - when all that keeps the outdoors firmly outside is a wall of glass. Pocket doors (sliding doors that can be housed inside cavity walls when open) have a limited opening width span but can offer good views through wide glass panels, in excess of a metre. It is important to ensure that the system complies with insulation regulations regarding the cavity wall as well as the double glazing.
Bi-folding sliding doors are now very popular in a number of frame styles: timber, PVC or coated aluminium are the main construction materials. Bi-folding doors have a maximum individual door width of one metre or less and each door has side frames that encloses the double-glazing unit and enables the hinges to be affixed (and/or the locking mechanism). This means that the slimmest frames, which tend to aluminium, are at least a couple of inches wide which, when two doors are together, is a visual interruption of a minimum eight inches and usually considerably more, sometimes double.
Double glazed slide and pivot doors are the most recent innovation, developed in the UK as a slimmer framed alternative to bi folding doors, as there are no hinges to be attached. Instead of folding, concertina style, as it slides to the side of the opening, each door slides individually to pivot 90 degrees when it reaches the side of the opening. An advantage of this system is that a door sized walk through gap may be left anywhere along the opening. (Indeed, several gaps, if required.)
Slide and pivot doors can have frame widths of approximately 19 millimetres or three quarters of an inch, usually in aluminium, or they can be frameless. Frameless glass doors will still have an opaque area of a similar width, which is the gasket seal of the double glazed unit.
Additional information for sourcing and selecting your retractable doors:
When choosing patio doors, it is advisable to check that the double glazed unit has the kite mark and that frames are fit for purpose, e.g. PVC frames should be reinforced for strength and wooden frames should be constructed of suitable, seasoned timber, otherwise there may be warping, swelling and shrinking. Aluminium frames should be 'thermally broken' meaning that an insulating barrier should be present between the inside and outside elements of the metal frame.
All doors should be suitable for the extremes of damp and dry conditions experienced in the UK. If you purchase from an importer, make sure that they have adhered to British building regulations. If you buy the product and the installation service separately, be aware that if something goes wrong, it may be difficult to determine which party is responsible.