Guide to Patio Door Types

Traditional or modern? typical or current? Varying tastes and different architectures throughout the years, in addition as innovations and enhanced lifestyles, have given rise to the wide choice in patio door variations currently obtainable in Britain. This article aims to describe the types of patio doors – their styles and functionality, similarities and differences, together with some of their main advantages and popular options – in order to provide readers with an informative guide.

Styles: French doors, sliding panels, retractable bi-folding doors, slide-and-pivot doors.

The latest patio doors innovation is slide-and-pivot doors. Developed and launched since 2007/8, slide-and-pivot doors incorporate the major benefits of bifolding doors and sliding patio doors. Comprising a number of individual glazed panels that fit snugly together when closed, there is a master door that can be opened with a standard (pivot) action, enabling the other doors to be moved, individually, along the top and bottom guides; as each door is moved to the end of the guides, it can also pivot open to increase the access width between the divided areas ( to a suggested maximum of approximately 8 metres).

These are also called slide and turn or slide and swing. Because slide-and-turn doors have no hinges, there is no requirement for a strong side frame; its only purpose is to cover the gasket that seals the double glazed unit. This method that the views afforded by the area of patio doors have minimal interruptions. At the time of writing, there are two versions of frame-less glass doors obtainable in the UK, both using the slide-and-pivot technique: one manufacturer supplies their frameless glass doors with kite-marked double glazed units which have a visible seal, the other uses an almost transparent method of sealing their double glazing. current by design, the absence of visible characteristics make frameless glass doors a viable option for period similarities.

Bi-Folding doors were launched around the turn of the century; they can be installed in place of French doors, where both doors are hinged to fold as they open together to one side. Bi-folding doors can also span an opening to around 7 metres wide, depending on the frame chosen. A master door can be placed amongst the doors, at the ends or in the middle, wherever the opening is required; this door is a standard (pivot) opening door which enables the other doors to be pushed to the side or sides of the aperture, resulting in a sliding-folding action, concertina-style, to maximise the width of the opening between home and garden or conservatory.

Originally, patio doors were all of the French Door variety; that is, a pair of doors that are hinged at the sides and open from the middle, each door pivoting in- or out-wards. French doors are nevertheless popular, especially with builders of new homes, as they are comparatively cheap and easy to adjust to in place of windows and offer an different evacuation route for families, especially for elderly or disabled people, to meet improved fire safety requirements.

Arguably, French doors could be considered as retractable as each door can be pulled back. The advantage of retractable doors is that maximum access is possible between the two sides of the aperture while sliding panel doors generally overlap unless built to retract into a recess.

In the mid-20th century, sliding doors became very popular – two or three panels of glass that slide along grooves in the floor. To discriminate them from traditional French doors, they were marketed with the thoroughly modern name of Patio Doors and this is often the image people have today when that term is used. Easily installed in place of a window, the immediate advantages were additional natural light and access to the garden. They also became a popular option to use where a pivot door opening space was limited or where the aperture was wider than a pair of French doors. Older installations were typically single-glazed, inclined to warping and usually became difficult to slide open and closed. nevertheless obtainable today but in a developed form with double glazing and rollers for easier sliding, the popularity of sliding doors during this century has declined as bifolding doors attained market proportion.

Frame Styles – timber, metal, pvc, composite, frameless, profiles and sight lines.

Patio doors comprise an outer frame plus individual door frames. These can be made from wood (soft- and/or hard-wood), metal or alloys (usually aluminium), pvc (polyvinyl chloride, a thermoplastic polymer – the u stands for unplasticised) or a composite material, which may comprise any of the foregoing materials plus grp (glass strengthened polymer). There is also a style known as frameless, where the vertical sides of each door have no frames.

Generally, timber frames are considered more traditional and can look beautiful! Hardwood such as oak is, as the name indicates, far more hard-wearing than a softwood such as pine. Weather, especially strong sun, can take its toll on timber frames which could need to be varnished or painted yearly. Wooden frames can expand and spread with humidity, consequently opening and closing doors can require force and gaps can allow draughts in colder temperatures.

Metal frames, usually aluminium, provide strength in a compact form. As notoriously good conductors (which is a bad attribute for insulation), frames made from aluminium are thermally-broken, which is a good attribute. It method that the metals on the inside and outside of the door frames are not joined, preventing the temperatures from being transferred between them. A bare metal frame would look completely unattractive so it is powder-coated in a choice of over 100 standard colours, including a white that resembles pvc.

As with timber, the quality of PVC frames obtainable can vary – and generally, you get what you pay for. The better ones will usually be strengthened with metal, internally, for greater strength but the cheaper options can be a nightmare to live with – sticking, twisting, splitting, discolouring, warping – often within a very short time. Most usually supplied as white, some manufacturers offer limited colour options or wood effect finishes.

Generally stronger than pvc, composite patio door frames vary with each manufacturer, offering a variety of finishes.

Whilst frameless doors have no side frames, the top and bottom of each door requires a mechanism, typically presented in aluminium, to allow it to slide within the top and bottom guides. Frameless glass doors have the best sightlines.

Sightlines is the term used to describe the interruptions in the view by the doors; in other words, the width of the vertical opaque areas between the glass when the doors are closed. On hinged doors, such as French doors and bi-folding doors, timber and PVC frames generally have general sightlines because, unlike aluminium, narrower frames would not be strong enough to be fit for purpose. As a guide to the width of two frames together, cheaper PVC door frames can go beyond 200mm, aluminium frames are typically between 135mm and 160mm and frameless patio doors sightlines are under 40mm. Depending on the width of each door and the number of doors to be installed, the difference in glass to frame ratio could be meaningful.

Door profiles – the width of the visible door edges when open – may be a consideration. Additionally, some door profiles are ugly, showing mullions or working parts that would be better hidden from view.

Glass – Kitemark, thermal performance, tempered, unbreakable, toughened, tinted, Georgian, leaded-light, stained glass, integral blinds.

All patio doors are required to have double glazing, although glass room dividers and glass doors to non residential similarities can be single glazed tempered unbreakable glass.

A visible kitemark on the glass is the consumers assurance that the double-glazed unit has been manufactured to British standards. The BSI has numerous standards, including U-value verification, Window Energy Rating and Window Installation. The lower the U-value, the better the thermal performance and most local authorities will require this to be 1.8 or better to meet building regulations.

Some manufacturers offer optional extras, such as tinted glass, anti-sun, laminated, obscured glass and Argon-filled double-glazing. It is also possible to match existing period features by specifying a Georgian bar or leaded-light in rectangular or diamond style. An inventive option is switchable privacy glass which enables molecules inside the double-glazing to become transparent or opaque at the press of a button; this is expensive, though, typically doubling the original price of good quality patio doors.

An different solution is to order patio doors with integral horizontal blinds, factory sealed inside the double-glazing cavity. Proven to be reliable, the blinds can be operated via a magnet system (there is an different electronic option) that enables the slats to be easily angled to control the amount of light filtering by and can also raise and lower the blinds for maximum light or shade. A major advantage of opting for internally sealed blinds instead of separate blinds is that they are totally maintenance-free – no arduous dusting or cleaning – and because the blinds are encapsulated inside the glazed panels, they are exceptionally difficult to break.

Hardware, Rolling, Thresholds and Security

French doors and bi-folds need hinges that are strong enough to resist the weight of the doors. Sliding doors (including bi-folds) can be supported from the top or rest on the floor. Top hung systems tend to be easier to slide and will ease low thresholds.

Thresholds can be raised or virtually flush if the floor area is appropriate. Raised is usually cheaper and may be more appropriate to certain environments; other factors to consider are access by wheelchair users, young children and elderly, infirm or slightly sighted people who may be liable to trip.

Consideration should be given to how obtain patio doors are. Not only the quality of the frames and glass but whether the doors can be unlocked from the outside. French doors are often purchased off the shelf and provide access from both sides while bi-folding doors are often made to measure and can be supplied with locks on the inside only. Multiple door systems may have meaningful-locks for each of the pairs of doors for additional security.

Access & Opening Widths

To recap, French doors come in pairs and consequently the maximum access width is in the vicinity of 2 metres. Sliding doors comprise two, three or four sashes within a frame, the larger systems opening to provide maximum access width of approximately 3 metres.

Bi-folding and slide-and-pivot door systems are fully retractable, maximising the possible access width. The width-span of bi-folds is governed by the stress of the hinged doors, consequently, a link of six doors is considered the maximum although, in theory, two of these could be installed to form a centrally opening retractable glass wall of twelve doors spanning 12m, provided the over beam can be trusted (reputable companies will probably advise against this).

Without hinges and cumbersome frames, slide-and-pivot doors are lighter and function independently, consequently their installable width span is restricted only by the length of the over-beam to which the upper guide needs to be attached. The upper and lower guides must be consistently equidistant along the complete width of the aperture for the doors to slide. This system has been tested to approximately 8 metres.

Delivery & Installation

As before stated, French doors can usually be purchased off the shelf to standard sizes, as can smaller widths of sliding doors and pvc or timber bi folding door systems.

If purchasing a system that is made to order, it is advisable to ensure that it is manufactured in the UK. Main benefits include adherence to British standards and delivery timescales (not only for the initial import but for later parts or problem solving).

When comparing prices, include cost of buying the door system, delivery service, installation labour (if d-I-y, cost of appropriate tools and materials), making good and clearing the site. Price is not everything, though. Consider the time it takes for the installation to be completed – typically, an experienced team from the supplier will complete the job in a day so that home-owners can enjoy using their new patio doors as soon as possible.

Commercial Use

Patio doors are generally installed in residential similarities but are also popular in restaurants, canteens, reception areas, sports halls, swimming pools and communal areas. Where double-glazing isnt required, single-glazed frameless slide-and-pivot doors may be preferred – reception areas, enclosing a terrace or cloisters, shop fronts in shopping malls and conference area partitions.