Bi folding-sliding door frames are typically made from timber, PVC (Unplasticized PolyVinyl Chloride) or Aluminium.
Bifolds that have been designed and developed using resilient aluminium have the benefits of greater strength and therefore suitability for use for openings up to 7 metres. The strength of the material enables the frames to be of slimmer design than with other materials, meaning that the greater amount of glass facilitates a better view and more light, and, by the same reasoning, the profiles (the depth of the glazed door unit) can be narrower so that the doors occupy less space when opened and stacked to the side of the aperture.
The aluminium is technique thermally broken, which means that the internal and external components of each bifolding door frame has a thermal division to ensure that the inside and outside of the frames do not touch and therefore do not conduct heat or cold from one surface to the other, keeping the temperatures inside and outside completely separate.
With aluminium, your view is through the glass, not at the framework. Because of its strength, aluminium is used to create the slimmest of bifolding door frames: a narrow profile plus a view through more glass. Wooden and pvc frames, even re-enforced with metal for additional strength, are wider.
Aluminium is also less prone to damage than timber or plastic. It will not require annual maintenance, as timber may do, especially if exposed to full sun. When aluminium framed doors are opened or closed, they do not tend to stick in the heat (like PVC) nor in the wet (like timber) and, unlike the cheaper do-it-yourself plastic bifolds or french doors, they feel firm and permanent.
The aluminium frames are powder-coated in a choice of industry-standard RAL colours. The finished bifolds, whether white, sepia, green, silver, graphite, etc., are virtually maintenance-free - perhaps requiring a wipe down with a damp cloth now and then. No painting or varnishing - ever.
Some bi folding door systems have a low threshold which is particularly useful when installed as a room divider or doorway to the conservatory but also for ease of access with patio doors when it is coupled with a low sill.
A good example of British made aluminium framed slimline bi folding doors with narrow profiles and low sills, available with a number of options including integral blinds within the glazing cavity and a choice of almost 200 frame colours, is the sliding- folding patio door system.