Bifold Door Installation London & Surrey

Aluminium Bifold Door Supply and Installation

Thermally broken aluminium bifold doors achieve whole-doorset Ud values of 1.4 W/m²K or lower under Approved Document L, engineered with polyamide thermal barriers, multi-point shootbolt locking to PAS 24:2022, and bottom-rolling stainless steel carriages carrying panel weights up to 120 kg per leaf. Configured in 2 to 7 panels spanning up to 8.4 metres, odd-number leaf configurations provide an independent traffic door for daily access, while structural lintels must maintain live load deflections under 2 mm to prevent top-guide binding.

Window Fitters Ltd supplies and installs aluminium bifolding patio doors for rear extensions, open-plan kitchens, and living spaces across Greater London, Surrey, and the South East from our Croydon HQ via structured travel tiers (<15m local at £540/day, 15-45m extended at £580/day, >45m outer Surrey with half-day minimum). Bifold doors fold and slide flat against one wall, opening up the full structural width between your room and garden. Every doorset is manufactured to your exact opening dimensions using thermally broken aluminium profiles, fitted with stainless steel rolling gear, and fully compliant with Approved Document L insulation and Approved Document Q security standards.

Our CSCS-carded master installers fit systems from leading extruders including Origin, Smart Systems, Cortizo, and Schüco, backed by £5,000,000 Commercial Public Liability and £10,000,000 Employers Liability insurance.

Labour-Only Bifold Fitting

If you have already purchased your bifold doors from a trade supplier or online manufacturer, our glazing teams are available for labour-only installation. We charge transparent day rates of £540 to £580 per day (£540 local, £580 extended) for a two-man team, or fixed per-leaf rates of £60 to £90 per panel depending on size and access. This professional fitting service includes laser levelling, structural toe-and-heeling, and perimeter sealing to BS 8213-4 standards. Read more about bifold door costs in London or explore our South West London door installation coverage.

How Bifold Doors Work Day to Day

A bifold doorset consists of multiple glass panels hinged together. One panel, called the traffic door, opens independently like a standard French door for everyday access without disturbing the other panels. When you want the full opening, you release the shootbolts on the remaining panels and slide the entire set along a bottom track, where they fold and stack flat against the wall.

Most residential bifold doors run on a bottom-rolling track system, where stainless steel wheels sit inside a recessed aluminium channel in the threshold. The top guide rail keeps the panels aligned but does not carry the weight. Some commercial systems use top-hung tracks where the panels hang from overhead rollers, keeping the floor track-free, but these require a significantly stronger lintel above.

Single-finger operation is realistic on a well-installed system. The panels should glide smoothly without forcing. If they feel stiff or gritty within the first year, the bottom track probably needs clearing of building debris or the rollers need adjusting.

Systems We Install: Profile Sightline Comparison

Profile sightlines dictate both visible glass area and structural rigidity across multi-panel openings:

Panel Configurations and Structural Widths

Aluminium bifold doors are available in 2-panel through to 7-panel configurations. The number of panels depends on your structural opening width:

Panels can fold inward or outward. Outward folding is more common because it keeps the stacked panels outside the room, freeing internal floor space. Inward folding suits properties where external space is limited, such as balconies or narrow patios. Position the traffic door on the side you approach most often from inside the house (typically the kitchen side) to save opening the full set every time you step into the garden.

Thermal Insulation and Glazing Options

All aluminium bifold profiles use polyamide thermal breaks (PA66-GF25), a non-conductive plastic bridge between the inner and outer aluminium faces that prevents cold transfer through the metal frame. Combined with argon-filled low-E double glazing, most systems achieve a whole-door Ud of 1.3 to 1.5 W/m²K, satisfying Approved Document L. Compare thermal calculations in our window U-value guide.

• Standard low-E double glazing (28 mm units): The default for most residential installations, balancing thermal performance, weight, and cost.
• Triple glazing (44 mm units): Achieves Ud values down to 0.8 W/m²K. Heavier sealed units require heavy-duty rollers, best suited to north-facing or exposed openings. Read our triple glazing guide.
• Solar-control glass: Neutral metallic coating that reflects up to 70% of solar radiant heat while maintaining visible light transmission, preventing south-facing rooms from overheating under Approved Document O.
• Self-cleaning glass: Titanium dioxide coating that breaks down organic dirt in sunlight and sheets clean in rain, practical for upper-floor or hard-to-reach installations.
• Acoustic laminated glass: PVB interlayer reduces external noise by 3 to 5 dB beyond standard double glazing, conforming to Approved Document E sound standards.
• Safety glass: All glass in bifold doors is toughened safety glass conforming to BS EN 12600, as required by Approved Document K for full-height glazed doors.

Threshold Types and Part M Compliance

The threshold is the bottom rail that the doors close onto. Selecting the right threshold is vital for exposed London and Surrey properties:

• Standard rebated threshold: A weather-rated aluminium sill with a raised upstand (typically 20 mm to 40 mm) that the door panels close against with double rubber compression gaskets, delivering maximum water tightness against driving rain.
• Low-profile Part M threshold: A flush or near-flush sill with a maximum 15 mm upstand, designed for step-free wheelchair and pushchair access as required by Approved Document M. Sunk into the floor screed and combined with an external linear Aco drain to prevent water pooling. Explore our Part M door thresholds guide.
• Track drainage: Under Approved Document C moisture rules, water entering the track through panel gaskets exits through weep slots at each end. Clearing the track twice a year prevents water pooling.
• Laser-levelled sub-base: Bottom tracks must be packed and bedded solid along their entire length. Even a 2 mm deflection in the floor slab will cause intermediate roller carriages to bind.

Security Locking and Shootbolt Operation

Residential aluminium bifold doors use multi-point hook locking systems. The traffic door locks with a multi-point espagnolette handle engaging hook bolts into the frame head and sill. The remaining panels lock with internal top and bottom shootbolts that engage into the track and head rail.

The traffic door cylinder should be a 3-star TS007 anti-snap cylinder, tested to resist drilling, bumping, picking, and snapping attacks. This satisfies Approved Document Q (PAS 24) security requirements for ground-floor openings in new dwellings. View our door hardware and locking guide.

When locking up at night, always engage the traffic door handle fully (lift and turn) and check that each intermediate panel shootbolt has dropped into its floor keep. A panel that appears closed but has not engaged its shootbolt can be lifted out of the bottom track.

Colour Finishes and Dual-Colour Choices

Aluminium bifold frames are finished with marine-grade polyester powder coating that resists UV fading, salt corrosion, and surface scratching. Standard colours available without extended lead times include:

• Anthracite Grey (RAL 7016): The most popular finish for contemporary extensions. Explore our anthracite grey windows and doors guide.
• Jet Black (RAL 9005): A bold, modern finish often paired with dark brickwork or contemporary contemporary weatherboarding.
• Traffic White (RAL 9010): Clean, traditional finish matching existing white frames on the property.
• Dual-colour finishes: Different colours inside and outside allow you to match external brickwork while keeping interior frames light and neutral.
• Custom RAL colours: Any custom RAL colour can be specified with a short fabricator lead-time extension.

Structural Opening Prep and Lintel Sizing

Bifold doors span wide openings, typically 3 to 6 metres. Under Approved Document A (Structure), the wall above must be supported by an engineered structural lintel capable of carrying the full masonry and roof load across that span. For openings wider than 2.4 metres in masonry walls, this usually requires an engineered structural steel beam (RSJ) rather than a standard concrete lintel, with live deflection calculated to under 2 mm.

During our technical site survey, our fitters check:

• Reveal depth: How deep the brickwork opening is from the outer wall face to the plaster line, determining frame setback and sub-frame requirements.
• Plumb and square: Measuring opening dimensions in three positions (top, middle, bottom for width; left, centre, right for height) with a 10 mm overall deduction for expansion and laser plumb adjustment.
• Threshold and floor levels: Finished floor levels relative to the external patio slab to verify Part M compliance and sub-cill drainage detailing.

On-Site Fitting and Commissioning

A typical residential bifold installation takes one full working day for a 2-person glazier team on 3-panel to 5-panel sets. Existing frames are removed carefully with temporary propping if required. The new outer frame is positioned, laser-levelled, and mechanically anchored to the masonry with heavy-duty fixings at 600 mm centres.

Perimeter gaps are insulated with low-expansion foam and sealed externally with neutral-cure silicone conforming to Approved Document C. Sashes are hung on the track, toe-and-heeled with load-bearing setting blocks to transfer deadweight to the hinge side and prevent sash drop, and tested for single-finger glide operation.

Track Cleaning and Hardware Maintenance

Aluminium bifold doors need very little routine maintenance, but a few simple checks keep them operating smoothly:

• Track clearing (twice yearly): Vacuum dirt, grit, and leaves out of the bottom track channel and clear weep drainage slots to prevent water pooling.
• Roller adjustment: If panels start to drag, adjustment screws on each panel raise or lower the rollers by a few millimetres to correct minor settlement.
• Lock and handle lubrication: Apply light machine oil or silicone spray to multi-point hook bolts and shootbolts annually (avoid heavy grease). Use dry graphite powder on anti-snap lock cylinders, not WD-40.
• Frame cleaning: Wipe aluminium frames and rubber gaskets with warm soapy water to maintain weather-tight flexibility. View our troubleshooting and maintenance guides.

To arrange a site survey for bifold door supply and installation across London and Surrey, call Window Fitters Ltd on 020 3411 0589, message us on WhatsApp to share photos, or submit your details via our quote request page.