Horizontal
Long, low lines- Seam
- Panels run across
Courses run across the elevation and the recess reads as a horizontal shadow line.
System 03Wall cladding · Soffits
Flat lock
A flat skin with a fine recessed joint, folded and interlocked on all four edges.
4
Interlocking edges
A welt folded on every side
300mm
Maximum clip centres
Concealed under the upper edge of each panel
530mm
Maximum panel width
Standard 330 mm and 430 mm
0mm
Stands off the face
The only line is the recess between panels
The profile
A flat wall,
one fine line.
Flat lock panels are folded with an interlocking welt on all four edges and a recess along the joint, so the wall reads as one smooth surface broken only by a fine negative line.
Panels are made to order from 100 mm wide, so the coursing can be set out to land on openings and corners, and they run vertically or horizontally.
SectionFlat lock panels on a plywood deckNot to scale
- 01Interlocking weltFolded on all four edges, so panels hang off each other
- 02Recessed jointA negative detail between panels
- 03Concealed clipUnder the upper edge of each panel, at max. 300 mm centres
Vertical
Tall, slender lines- Seam
- Panels run up
Panels run up the building for a finer, taller elevation.
Why specify it
Six reasons architects
choose flat lock.
From the setting out on the drawings to the warranty at handover, this is what the system gives a project.
01The flattest wall we fold
Nothing stands off the face. The only line is the recess between panels, and it reads as a shadow rather than a rib, which is why flat lock suits facades that should be quiet.
02Cut to the elevation
Panels are made to order from 100 mm wide, so the coursing can be set out to land on openings, corners and floor levels rather than running past them.
03Concealed clip, minimalist system
Every fixing sits on a hidden clip under the upper edge of the panel. Nothing passes through the face, so the wall is metal and a shadow line and nothing else.
04Either direction
Panels run vertically or horizontally from the same profile, so the grain of the elevation is a design decision rather than a product limit.
05It follows a radius
Grooves laser cut into the back let the panel bend to a curve rather than facet around it, so a curved wall or soffit keeps the same flat face and the same joint spacing as the straight runs beside it.
06Little waste
Panels are cut to size from coil in our workshop, and widths can be chosen to use the coil fully.
Technical details
The layers
Flat lock hangs on concealed clips over a continuous plywood deck. These are our standard layers, from the face inwards.
- 01Flat lock panelZinc 0.7 mm, copper 0.6 mm, aluminium 0.7 mm, Colorbond and UniCote 0.55 mm, Corten 0.7 mm
- 02Concealed clipsUnder the upper edge of each panel, at max. 300 mm centres
- 03Waterproof membraneFully breathable and waterproof
- 04Structural plywood18 mm to AS 2269
- 05Studs or top hatsContinuous, at max. 600 mm spacing
Structure and insulation are by others. Clip spacing is confirmed for each project against the site’s wind loads.
Section through the wall layers. Not to scale.
Specification
by metal.
- Panels run from 100 mm wide: to 500 mm in aluminium, 430 mm in zinc and copper, and 530 mm in Corten.
- Custom widths are made to order, up to 450 mm wide depending on the application.
- Panels run vertically or horizontally.
- Panel length: talk to us at design stage.
- Aluminium is 3005 alloy, minimum H42 temper, PVDF coated over a primer with at least two paint layers.
| Metal | Thickness | Standard panel width |
|---|---|---|
 Zinc (VMZINC) | 0.7 mm | 430mm |
 Copper (Aurubis) | 0.6 mm | 430mm |
 Aluminium (VESTIS, PVDF) | 0.7 mm | 330mm |
 Colorbond steel | 0.55 mm | 330430mm |
 UniCote steel | 0.55 mm | 330430mm |
 Corten | 0.7 mm | 330530mm |
- Panel width
- 100 to 530 mm; standard 330 mm in aluminium, 430 mm in zinc and copper
- Thickness
- Zinc 0.7 mm, copper 0.6 mm, aluminium 0.7 mm, Colorbond and UniCote 0.55 mm, Corten 0.7 mm
- Joint
- Interlocking welt on all four edges, with a recessed negative detail
- Fixing
- Concealed clips at max. 300 mm centres, under the upper edge of each panel
- Substrate
- 18 mm structural plywood to AS 2269
- Underlay
- Fully breathable and waterproof membrane
- Orientation
- Vertical and horizontal
- Applications
- Wall cladding, Soffits
Concealed
clips.
Each panel is held by concealed clips under its upper edge. The panel above covers them, so nothing passes through the face and the wall stays unbroken.
Clips
Fixed to the plywood under the upper edge of each panel, then covered by the panel above.
Max. 300 mm centres
Substrate
Structural plywood over a breathable waterproof membrane.
18 mm to AS 2269
Details and
drawings.
Typical details for documentation. Select a drawing to view it full size, or download the full detail set.
Literature
2 documents
Full detail sets
Eaves, ridge, valley, parapet, corner, window and penetration details as PDF, with the manufacturer data behind them.
Browse the library
How we deliver flat lock
- 01
Review
We check the drawings, exposure and buildability, and recommend the metal and gauge.
- 02
Shop drawings
Our drafters set out every pan, clip and junction for architect approval.
- 03
Fabrication
Panels are folded in our 2,000 m² Sydney workshop and QA checked before dispatch.
- 04
Installation
Our own crews install under a dedicated project manager, then hand over warranties.
Questions
7 answered
Flat lock questions
The questions estimators and drafters answer most often. If yours is not here, send the drawings and we will answer it against your project.
Ask about your projectWhat is a flat lock panel?
A flat metal panel folded with an interlocking welt on all four edges and a recess along the joint. Panels hook into each other, so nothing stands off the face and the only line is the recess.
How wide are flat lock panels?
From 100 mm up to 500 mm in aluminium, 430 mm in zinc and copper and 530 mm in Corten. Standard widths are 330 mm in aluminium and 430 mm in zinc and copper. Wider panels are possible but can show distortion.
How is flat lock fixed?
On concealed clips under the upper edge of each panel at a maximum of 300 mm centres. The panel above covers them, so no fixing passes through the face.
What is the difference between flat lock and shingles?
They share the same interlocking welt. Flat lock is laid as larger rectangular panels for a flat, quiet facade with a recessed joint; shingles are smaller and laid in courses, so the pattern itself becomes the finish.
Can flat lock be curved?
Yes. We laser cut a line of grooves into the back of the panel so it bends to the radius without the face buckling. The spacing is set in SolidWorks from the radius on the drawings, so each panel is cut for its own position on the curve.
Can flat lock be used on a roof?
We specify it for walls and soffits. VMZINC publishes the flat lock panel as a facade system, so for roofs we would move you to standing seam, snap lock or shingles.
Which metals can flat lock be made in?
Zinc at 0.7 mm, copper at 0.6 mm, aluminium at 0.7 mm, Colorbond and UniCote steel at 0.55 mm, and Corten at 0.7 mm. Aluminium must be 3005 alloy, minimum H42 temper, with a PVDF coating.
Start your next project.
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Priced by system, metal and area.