Composite bi folding doors - SFK82

Composite bi folding door system which combines a solid section of timber to the inside and aluminium cladding to the outside.


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Composite bi folding doors - SFK82

The SFK82 composite folding sliding door system combines a solid section of timber to the inside and aluminium cladding to the outside, leaving a clean modern look to the outside and a more traditional appearance to the interior décor of the building. The SFK82 composite bi-folding door provides the ultimate ‘wow’ factor to the aesthetics of any extension, renovation or new build project. With numerous special features and in a range of colours and finishes, this combination timber and aluminium sliding folding door range is the ideal solution for kitchen/diner extensions, balconies, sunrooms and conservatories. A range of windows and doors are also available to complement the folding sliding door frames.


  • Sunfold SFK82 140mm vertical frame sightlineEach panel can be manufactured to maximum widths of up to 1100mm and heights of up to 2800mm (limitations apply)
  • Doors will stack inside or outside, left, right, or split
  • Top hung (suspended) or bottom rolling (floor supported) options are available
  • Slim sightlines - only 140mm
  • Marine treatment available on aluminium for salt-water environments
  • Solid timber sections are triple laminated to avoid warping and made from knot free Pine, Meranti or Oak
  • Fully finger safe and severe weather rated seals and gaskets
  • Sunfold SFK82 fully finger-safe gasketsThree tracks available, flush, low-level semi-weathered and fully weathered
  • Thermally broken aluminium top and bottom tracks
  • U-Values of between 1.5 to 1.7 W/m²K with standard glass (lower values possible)
  • Complies with the revised part of Document L Building Regulations (October 2010)


    - Watch the Sunfold show-reel
    - Folding sliding door feature check list
    - Stainless steel handle options, only satin (brushed) and polished stainless steel are recommended for external use
    - Marine treatment for superior salt-water protection
    - RAL colour chart
    - Sikkens colour chart
    - Watch the 3 panel operation video
    - Watch the 4 panel (3 left & 1 right) operation video


Folding sliding door configuration diagram (In/Out - Left/Right)

With the flexibility of our folding sliding doors, any project can be catered for. The following diagrams show the configuration options for 1 to 7 panel sets. This sequence continues on for however many panels you need.

Each of the diagrams below show opening-out door sets. For each there are three other variations as the diagram to the right shows.


1 panel (single door)2 panel sets, both left & ><img style=3 panel sets, all left & 2 left 1 right45 panel sets, all left, 4 left 1 right & 3 left 2 right6 panel sets, all left & 5 left 1 right6 panel sets, 4 left 2 right & 3 left 3 right7 panel set, all left & 6 left 1 right

7 panel set, 5 left 2 right & 4 left 3 right


Tracks are available at three levels, flush (with brush seals), low-level semi-weathered and fully weathered.

The tracks can be recessed into the floor to allow for smooth transitions between internal and external spaces. The track type determines both its level below the finished floor level (including carpets, tiles or other floor coverings) and the weather-tightness of the door sets.

NB: With all track types the drainage of water running down the front of the doors and out from the centre of the track needs to be considered.

Flush track

SFK82 flush track detail (bottom running opening out)

  • The smoothest floor transition available
  • Track can be recessed 31mm below the final finished floor level on the inside and outside
  • Brush seals run along the inside and outside track edge
  • Drainage needs to be consider along the outside track edge.

  Technical details
  - Bottom running opening out
  - Bottom running opening in
  - Top hung opening out
  - Top hung opening in


Low-threshold semi-weathered track

SFK82 low-level semi-weathered track detail (bottom running opening out)

  • A minimal transition between internal and external floor levels
  • Track can be recessed 20mm below final finished floor level on one-side and 36mm on the other
  • Gasket seal on one track edge provides a watertight and airtight barrier

  Technical details
  - Bottom running opening out
  - Bottom running opening in
  - Top hung opening out
  - Top hung opening in


Fully weathered track

SFK82 fully weathered track detail (bottom running opening out)

  • The maximum amount of weather protection available
  • Inside and outside edge gasket seals provide complete protection against water and air infiltration
  • Track can be recessed 20mm below final finished floor level on out-side and 60mm on the other
  • Ideal for coastal facing properties or areas that experience severe weather

  Technical details
  - Bottom running opening out
  - Bottom running opening in
  - Top hung opening out
  - Top hung opening in



Sunfold SFK82 black shot-bolt handle

  • Lead doors are fitted with a 3-point locking mechanism that meets insurance companies’ requirements
  • Intermediate panel joins are held closed by internal shoot bolts top and bottom operated by a flat, sprung handle
  • Option of key locking shoot bolts are available on the inside only for added security
  • All key locking cylinders are Sunfold unique high security locks
  • Locks can be supplied keyed-alike if more than one door set is required

Sunfold high securuty lock cylinder and key

Unique high security locks

Our highest security locking system offering unique and advanced security features.

     •   Anti-pick shaped pins
     •   High security six pin cylinder
     •   Cylinder protected against drilling
     •   Magnetic pin protects against unauthorised entry
     •   Cylinder protected by anti-wrench reinforcement
     •   Magnetic key with moving component protects against unauthorised duplication
     •   Protection against forced entry through the use of 'Bump Keys'
     •   Possible to incorporate a master key system


Intelligent keys

Extra security with our unique key controlled lock changing system.

Red construction key for high security lock

Yellow main keys for high security lock- A construction key with red insert is used during installation



- Three main keys with yellow inserts. Upon completion these keys are used to recode the cylinder and exclude the construction key

White security key for high security lock


- One emergency key with white insert. If a main key is lost or stolen this key will
recode the cylinder again and exclude all previously used keys


(Additional and replacement keys are available on request. Along with other high security lock products)


    - High security locks

Colours & finishes

Standard timber finishes

Light oak sikkens stained e5-58-44-tDark oak sikkens stained d9-54-32-tTeak sikkens stained d5-51-29-tMahogany sikkens stained b8-29-15-tWhite painted RAL9016

Standard aluminium finishes

                                                            RAL 9016 Traffic White (Semi-gloss)DB703 Metallic Dark Grey

  • Timber is factory primed and can be finished in any Sikkens wood stains or micro-porous RAL coloured paint to suit any style and taste
  • External aluminium is available powder-coated to any RAL colour
  • Clear lacquer (003) is available as a standard finish for Oak and Pine
  • Standard finishes are dependent on choice of timber, Oak (clear lacquer, light oak, dark oak and teak), Meranti (white painted, light oak, dark oak, teak and mahogany), Pine (clear lacquer and white painted)
  • Pass door lever handles, shoot-bolt handles and back-plates are supplied black, white, silver or brown as standard
  • Handles and back-plates are available in RAL colours to match the frame, brushed/polished stainless steel lever handles are available from our in-door range
  • Gaskets are supplied in black (standard) but can be supplied as white or grey
  • Hinges and magnetic panel catches are supplied in anodised black (C35) or silver (EV1)

Marine treatment

Marine treatment is available on aluminium systems to protect against the aggressive corrosion of salt-water environments. Our marine treated system provides high quality protected components combined with a powder-coating process that is certificated to Qualicoat sea-side class.


The colours shown on this page are intended as a reference guide only. Timber is coated with either Sikkens stains or painted to a RAL colour. The Sikkens colour references shown will vary depending on the timber they are applied to. The colour tone of the stain can also vary along the length of any type of timber due to its natural properties. The RAL colour simulations displayed may not exactly match RAL®-identified colour standards. Please use current Sikkens or RAL colour publications for more accurate colours.


Standard 28mm double glazed unit (4/20/4) Argon gass fill with Low E coating

    • The SFK82 will accommodate glazed units up to 36 mm
    • Triple glazed units can be accommodated
    • Our standard 28mm unit comprises two panes of 4mm clear toughened glass, with an argon gas filled 20mm cavity incorporating a black warm-edge insulated spacer bar. The inner pane is equipped with a Low E (soft coat) thermally efficient coating. Units are manufactured to BS6206A and BS5713
    • Standard glass units provide a centre-pane U-value of between 1.1 and 1.2 W/m²K
    • Many solar control and tinted glass options are available
    • Transom rails, glazing bars and solid (non-glazed) panels can be incorporated into your door design
    • Venetian blinds are available to sit within the glazing cavity with manual ‘cord’ or electric 'battery’ operated controls


Anti-sun tinted glass

Anti-sun tinted glass is available in a number of colours, we promote green and blue tinted options. The tint can be used for visual appeal, to reduce glare or where a degree of solar control is required.

Reflex® glass

Reflex® glass can be provided as an upgrade option to our standard glazed unit. This 'smart glass' or 'solar control glass' is it is more commonly known, uses an invisible metallic coating which is applied to the glass using the latest coating technology. It provides additional performance and energy saving benefits in comparison to standard glazed units.

Benefits of Reflex® glass...
Reflex glass helps reduces penetration of solar heat energy
The invisible metallic coating on the inner surface of the external pane reduces the solar heat energy that can enter the room. Solar heat transfer is reduced by up to 75% compared to a standard double glazed unit. The subtle light blue tint reduces glare by up to 44% but still ensures good light transmission for both visual and thermal comfort.

Reflex glass improves insulation

The centre-pane U-value is reduced to 0.9 W/m²K with argon gas. This low U-Value offers improved insulation and reduces heat transfer through the glass. With better insulating glass the room will stay warmer for longer in winter and cooler for longer in summer, saving heating and air-conditioning costs.

Reflex glass has an easy-clean coating

An 'easy clean' external surface treatment to the glass reduces the need for cleaning and makes stubborn dirt easier to remove. The hydrophobic polymer coating promotes water run off which washes dirt and mess away with rain or water sprayed from a hose-pipe keeping the glass looking fresher.

Reflex glass units are fully quaranteed
The insulated glass units are fully guaranteed against unit seal failure due to the latest dual seal high performance manufacturing techniques. Using the very latest robotic manufacturing systems means that the glass is only touched by human hand at the very end of the process when it is 100% quality inspected.

Reflex glass is a cost effective solution
Reflex® is a cost effective solution for reducing solar heat and allowing for more comfortable living in summer and winter. In-glazed blind systems cannot be incorporated into Reflex® glass units but are not needed to help reduce light and heat penetration due to the other benefits provided. Reflex® is a more cost effective solution for to reducing light and heat penetration than in-glazed blinds.

Bespoke design details

It is possible to incorporate glass design details into or onto the glass of you doors.

  • Glazing bars can be fitted into the cavity of the glass unit.
  • Leading can be applied to the external face of the glass.
  • Logos, designs and other visual details can also be sandblasting into the glass or applied as opaque vinyl stuck onto the glass.

                   Internal glazing barsLeading glass detail to outside
We are happy to investigate requests for specific design details but require information on the specification that you would like. Some design detail options are not possible with in-glazed blinds or high-performance glass units.


Ventilation is often required by building regulations. Options can be incorporated into the door systems for rooms that do not have any other provision through windows, doors or ventilation systems.

Through-frame trickle vents

Through-frame vents are incorporated through the frame or a profile added to the frame providing a neat and un-obtrusive ventilation facility.

  • Our standard through-frame trickle vents provide ventilation of 2500mm² equivalent area (as per BS EN 13141-1:2004) per vent
  • A maximum of one vent for each panel in the system can be installed
  • For bottom running systems through-frame vents can be fitted through the top track
  • Top hung systems require an add-on to the top of the system for the vents to fit through
  • Vents can be supplied in black or white as standard.
  • The body of through frame vents can be supplied to any RAL colour.

                    Through-frame vent viewed externally (Black)Through-frame vent viewed internally (RAL7016)

In-glazed vents

In-glazed vents can be incorporated when through-frame options cannot be used. The vents sit on top or the glazed units reducing the glass height.

  • Our standard in-glazed trickle vents provide ventilation of 4100mm² equivalent area (as per BS EN 13141-1:2004) per metre of vent.

In-glazed vent viewed externally

Other options

Glass with in-glazed blinds

Glass units can be provided with Venetian slated blinds manufactured within the cavity, between the external and internal panes of glass.

  • Provides privacy for over-looked rooms
  • Removes the need for the extra cost of retro-fitted curtain or blind solutions
  • Blinds do not need cleaning as they are encased away from dust and dirt between the glass panes.
  • Blind slats are supplied in silver as standard, white and cream slats are also available
  • Units provide a centre pane U-value of between 1.1 and 1.2 W/m²K
  • In-glazed blind can be incorporated into double glazed units up to 1200mm wide

Manual 'cord' controlled blinds
- In-glazed manual 'cord' controlled blinds are supplied with transparent mechanisms and grey cords as standard.
- Mechanisms are also available in grey and white, cords in black and white

Watch a video of manual blinds in use

      In-glazed blind transparent top mechanism with grey cordIn-glazed blind transparent bottom mechanism with grey cordIn-glazed blinds transparent top backplate without cordIn-glazed blind transparent bottom mechanism without d

Electric 'battery' operated blinds

Watch a video of electric blinds in use.

                  Electric in-glazed blinds battery packElectric in-glazed blinds solar charging panelElectric in-glazed blinds wireless radio remote control
In-glazed blind systems cannot be used in connection with triple glazed units or high-performance glass, such as Reflex®, with specialist coatings on the inside face of the glass panes.


Fixed panels


  • Fixed panels provide glazed openings with no opening function
  • They allow for the maximum amount of light with the minimal amount of frame
  • Panels can be supplied as single panel sets or with vertical mullions dividing one panel into multiple openings
  • As standard fixed panels have a slimmer frame than that of a folding sliding door panel. Additonal frame can be
    added to the top, bottom and sides of a panel if it is important to ensure that sightlines are visually even between sets.

Case studies

Bi folding doors with added marine protection

Bi folding doors with added marine protection

When looking to retire, Mr & Mrs Wagner found the ideal spot on the Isle of Lewis where they could build their perfect home in keeping with the island’s architecture and low carbon footprint. 

Sliding folding doors for architect’s private residence

Sliding folding doors for architect’s private residence

Making the most of spectacular views is important for any development project and this was especially true for private residential project Gibney House. Set in an idyllic position, the rear aspect of the building was designed to incorporate the beautiful views through using sliding folding doors from Sunfold Systems.