By Julie Jarvis, Technical Director, DR Services
Architects and interior designers, as well as the housebuilders or developers on whose projects they are involved make many judgements based on price, quality and aesthetic taste; though this is only part of the process – as we can understand by looking at the significant differences between swinging and sliding doors.
Though the most contrasting characteristic is in the geometry of their motion – one a rotation while the other translates through a single plane – there are various other criteria to be considered. So what will decide the choice between swinging or sliding doors?
Certainly for the vast majority of domestic and even commercial situations, a basic swing door will suffice; but dozens of different factors can dictate that some type of sliding door installation may be appropriate or even essential.
The arc described by a swing door as it is opened is the single most relevant factor, in that the amount of clear space required in front of, and to the side of a doorway, can count against their use.
Although this is readily apparent, the full implications only impressed themselves upon most designers following the introduction of the Disability Discrimination Act. For an able bodied user, the act of turning a conventional door handle and swinging back the door leaf is completed without conscious effort. However, for someone confined to a wheelchair, or even a person encumbered with an infant, or heavy packages, the operation can be both inconvenient and potentially hazardous.
Since the advent of the DDA, we are used to seeing sliding door adaptations on quite humble high street outlets, while they far outnumber revolving doors in very high pedestrian traffic locations such as rail stations. What is more, top hung or bottom sliding gear can permit even very heavy door leafs to move aside easily and quickly with a minimum of noise and inconvenience. In fact D R Services can supply sliding door gear capable of dealing with leaf weights from 15 kg up to three tonnes, either opened manually or electrically powered.
Looking at the main regulatory requirements affecting sliding door systems, the Disability Discrimination Act requires a maximum force of 30 Newton metres to get a door rolling, and 25 Newton metres to keep it moving.
The Building Regulations also say you have to protect someone falling against an automatic sliding door, being injured by its movement. Some of the guard barriers used are quite obtrusive, but our aesthetic answer is in the form of a frameless section of safety glass or a simple stainless steel railing appearing out of the ground. The infill would be 10 mm toughened; or 12 mm toughened if it cantilevers out of a floor track.
One of the challenges that we are regularly set by clients for commercial applications is to create a sliding door that runs independently of the soffit, normally because there is a suspended ceiling that cannot bear weight. The Trojan 120 manual system can span openings in masonry walls and stud partitions, while the tracks can also be mounted across glass walls.
This can create a completely transparent division where glass doors permit or deny passage. The 120 kg weight limit for Trojan equates to an area for the door leaf of four square metres, depending on thickness,
There is also a growing market for curved doors where D R Services has introduced a totally visible, external stainless steel system which not only features rectangular section rail, it also conceals the wheels within a square housing. One of the stand-out projects where this has been used to offer visual impact is the headquarters of Kildare County Council, Ireland. There we created a series of 19 cellular offices, where the 2.4 metre high glass screens stopped well short of the ceiling level.
Sliding stacking walls in frameless glass are frequently high on the menu for interior designers to make the space more flexible; and at the Intercontinental Hotel on Hyde Park, D R Services created a glass wall which, when not in use, can be completely concealed behind oak panelling. The bespoke glass doors contain wire gauze for visual effect while the walls and ceiling are fashioned from 17.5 mm water glass where deep sand-blasting of the laminated layers creates the illusion of ripples.
Even more recently we have further expanded our portfolio of glass options so that a very wide selection of materials and fine wood veneers can be incorporated into laminated leaves. The glass interlayer can even be side lit for extra impact.
Finally for those clients who cannot decide between sliding and swinging doors, there is a hybrid product where the 100 mm top rail divides horizontally to allow the door to pivot. The split rail is then locked together for the door to slide aside.