Can it be weather-exposed without a roof?

Bi-fold is best under a roof overhang. For fully exposed walls we specify the lift & slide range instead.

Is a screen available for the open position?

Yes, a folding screen track runs with the door stack and closes the opening against insects in 20 seconds.

BF-40 Bi-Fold Doors

8-panel bi-fold · 75/90 mm profile · full glass

Four panel aluminium bi fold door opened onto a garden

BF-40

Up to eight panels that fold into a stack narrower than a door width.

8-panel bi-fold · 75/90 mm profile · full glass

Configurations

Glazing options

Lead time

35–45 days

Warranty

15 yr

Both documents are free — quoted against your project within 24 hours.

BF-40 frame section, thermal-break build. Photographed section, hardware and installation detail below.

Read the section

High-end custom is decided in the section drawing, not the brochure. These four layers are held to specification on every BF-40 unit we ship.

6063-T5 multi-chamber frame

Extruded alloy with internal chambers for stiffness without weight.

PA66 thermal-break bar

Glued and bonded polyamide isolation, continuous across the build.

EPDM double gasket

Two replaceable compression lines for air and water tightness.

Hardware & fixing

Concealed hinges, central multi-point lock

Technical detail

The section, the hardware and the fixings — photographed, not rendered. This is the level of detail your drawing office specifies against and your site crew installs to, on every unit that leaves the line.

Profile cross-section

Multi-chamber 6063-T5 extrusion with a continuous PA66 thermal-break bar. The section is where stiffness, insulation and drainage are decided in one drawing — and the four values in the performance band above are read straight off it.

Alloy

6063-T5, multi-chamber

Thermal break

PA66 polyamide, continuous

Gasketing

EPDM, two replaceable lines

Drainage

Concealed, positive slope

Frame profile — three internal chambers give the stiffness without the weight.

Thermal break bar visible in the window frame cross section — The continuous PA66 break bar isolates the outer and inner aluminium.

Window frame corner joint with glazing and gasket line — Corner joint with the glass pack in place — one continuous gasket line, concealed drainage.

The polyamide bridge breaks the conductive path that would otherwise run across the frame.

Door sections on the same platform, sized for the leaf load and the threshold.

Thermal break bar detail on the extrusion line — Thermal break bar, second detail — continuous PA66 from the extrusion line.

Hardware

Pre-fitted and function-checked on every sash before it leaves the line. Multi-point locking, key-operated handles and marine-grade sets are scheduled per project and listed in the hardware schedule that ships with the shop drawings.

Locking

Multi-point, per sash

Handle

Key-operated option

Finish

Marine-grade available

Check

Cycled at the factory

Multi-point locking bolt points on a door leaf edge — Multi-point locking — the handle drives bolt points top, bottom and on the meeting stile, not one edge.

Window handle with base plate and strike set and fixing screws — Handle, base plate and strike set — the full set, fitted and cycled before dispatch.

Black window handle with key cylinder — Key-operated handle for ground-floor and security specifications.

Chrome finishing aluminium window handle — Chrome finish for clean, high-traffic interior positions.

Window handle and strike plate with fixing hardware — Strike and fixings match the handle set; nothing is improvised on site.

Black multi-point lock set on a timber interior — The same locking discipline on the wood-aluminium interior line.

Installation

Factory-assembled and pre-glazed, so the tolerance work is done under a roof. On site the build is a three-zone detail — air, insulation, weatherproofing — and every crate arrives with the install guide and the sealant schedule for that market.

Arrives

Factory-assembled

Detail

3-zone: air / insulation / water

Guide

Per-crate install sheet

Sealant

Scheduled per market

Powder-coating line for the glazed sash units before packing — Every glazed unit runs the full pre-treatment and powder-coat line before it leaves the shop.

Surface pre-treatment line ahead of the powder-coating booths — Pre-treatment and powder coat — every profile runs the surface line before assembly.

Water penetration test — the spray rig running on a glazed unit at the quality gate — The test rig — air, water and cycle spot tests at the quality gate, before crating.

Worker hand-finishing a door leaf — wiped down and checked before packing — Every door leaf is finished by hand — sanded, checked and wiped down before packing.

Overview

A bi-fold door is a folding glazing system whose panels stack to one side, opening terraces up to 8 metres clear. BF-40 runs up to eight 550–950 mm panels on a flush threshold with concealed hinges, a central multi-point lock and an optional folding screen track for patios, restaurants and hospitality entrances.

A narrow-profile folding system for patios, terraces and hospitality entrances. Panels stack to the side in a compact rail, leaving a clear opening up to 8 metres. Flush threshold and integrated screens keep the stack tidy.

BF-40 installed view — BF-40 — Bi-Fold Doors

Models

Every BF-40 ships as one of the configurations below — specify by model code in your window schedule and it quotes line by line.

BF-40 4P

4 panels, 2 sliding · 4,200 mm clear
8–16 mm tempered

BF-40 5P

5 panels, 3 sliding · 5,100 mm clear
8–16 mm laminated

BF-40 6P

6 panels, 3 sliding · 6,000 mm clear
Laminated low-E

BF-40 8P

8 panels, 4 sliding · 8,000 mm clear
Laminated IGU

BF-40 SCREEN

Folding screen track, 20 s close
Stainless mesh

BF-40 configurations in place — BF-40 — configurations in place

Specifications

Profile system: 75 / 90 mm depth, narrow-stile panel design
Panels: Up to 8, each 550–950 mm wide
Clear opening: Up to 8,000 mm
Glazing: 8–16 mm tempered or laminated
Track: Flush threshold, integrated bottom rail, screen option
Hardware: Concealed hinges, central multi-point lock
Finishes: Anodised, powder-coated, RAL on request
Standards: Tested to EN 14351-1, EN 13830

BF-40 — profile and glazing detail

Material & craft

The layers held to specification on every BF-40 unit — the section drawing above, written out.

Folding geometry

Up to eight 550–950 mm panels on concealed hinges, four of them sliding, to 8,000 mm clear on a flush threshold with an integrated bottom rail.

Locking

A central multi-point lock closes the stack as one unit; the door leaf takes the street, the panels take the view.

Screen track

The BF-40 SCREEN variant carries a folding stainless mesh track that follows the stack — twenty seconds to closed.

What it's worth to you

Panoramic fixed glazing installed across a modern house elevation

Eight metres clear, eight panels, one locking point — the opening stays usable when it is mostly closed.

The hospitality entrance configuration is rated for the service pattern, with the 15-year warranty on the hardware line.

Under an eave overhang it is the patio wall; for fully exposed walls the schedule swaps to the LS-60 on the same platform — one drawing set either way.