Double lock
Roofs- Seam
- Folded twice, through 180°
- Pitch
- From about 3°
The second fold closes the seam tight against wind driven rain, so double lock is the choice for low pitch roofs.
System 01Roofing · Wall cladding · Soffits
Standing seam
25 mm seams on concealed stainless clips. Double lock for roofs, single lock for facades.
25mm
Seam height
Double or single lock
3°
Roof pitch from
Double lock; single lock from 25°
300mm
Maximum clip centres
Stainless, fixed and sliding
330to 530 mm
Standard panel width
Set by metal and coil
The profile
One pan,
two raised edges.
Standing seam is the system we fold most often.
Each pan is roll formed or folded to the setting out on the drawings and joined with a 25 mm raised seam. Concealed stainless steel clips hold it down and let the metal expand and contract. Double lock seams suit roofs down to low pitches. Single lock seams suit walls, soffits and roofs steeper than 25°, and panels can run vertically or horizontally, tapered or curved.
SectionDouble lock standing seam on plywood deckNot to scale
SectionSingle lock standing seam, wall, soffit or roof from 25°Not to scale
- 01Double lock seam25 mm high, folded twice on site to close the joint
- 02Pan330 mm standard in aluminium and steel, 430 mm in zinc, 430 or 530 mm in copper
- 03Concealed clipStainless steel, fixed and sliding, screwed to the deck under the seam
Single lock
Walls, soffits and steep roofs- Seam
- Folded once, to 90°
- Pitch
- Roofs from 25°, walls at any angle
A lighter seam that sits flatter. It suits facades, soffits and roofs steeper than 25°, and can run into a double lock roof as one continuous seam.
Why specify it
Six reasons architects
choose standing seam.
From the setting out on the drawings to the warranty at handover, this is what the system gives a project.
01Shaped to the design
Panel widths are set to suit wall and window lengths. Panels can be tapered, curved convex or concave, and broken with cross joints.
02Little waste
Pans are cut to length from coil in our workshop, and widths can be chosen to use the coil fully.
03Waterproof by detail
Every junction and panel connection relies on the metal itself to shed water, with no exposed fixings.
04Wall to roof in one line
Single lock wall cladding can connect to a double lock roof with a continuous seam.
05Light on the structure
About 2.2 kg/m² in 0.8 mm aluminium, 5.0 kg/m² in 0.7 mm zinc and 6.3 kg/m² in 0.7 mm copper, a fraction of the weight of tile or slate.
06Built to last generations
Zinc typically lasts 80 to 100 years and copper more than 100, with no paint coating to fail. Both are fully recyclable at the end of their life.
Technical details
The layers
Standing seam needs a continuous, fully supported deck. These are our standard wall layers, from the face of the building inwards.
- 01Standing seam panelZinc, copper, aluminium or steel, with a 25 mm seam
- 02Stainless steel clipsFixed and sliding clips, min. 0.4 mm, at max. 300 mm centres
- 03Breathable membraneFully breathable and waterproof
- 04Structural plywood18 mm, to AS 2269
- 05Ventilated cavity20 mm, formed by top hats or battens
- 06StructureContinuous wall studs or top hats at max. 600 mm centres
Main structure, insulation and the building’s waterproofing are by others. We confirm the layers for each project in the shop drawings.
Section through the wall layers. Not to scale.
Specification
by metal.
- Standard widths are set by the coil widths available, which keeps waste down. Wider panels are available but can show distortion or oil canning.
- Panels run vertically or horizontally on walls.
- Panel length: talk to us at design stage. For zinc walls, VMZINC recommends panels up to 4 m long, and up to 2 m on soffits.
- 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 | 430525mm |
 Copper (Aurubis) | 0.7 mm | 430530mm |
 Aluminium (VESTIS, PVDF) | 0.8 mm | 330525mm |
 Colorbond and UniCote steel | 0.55 mm | 330525mm |
- Seam height
- 25 mm
- Fixing
- Concealed stainless steel clips (fixed and sliding)
- Seam types
- Double lock (roofs from 3°), single lock (walls, soffits and roofs from 25°)
- Orientation
- Vertical or horizontal on walls
- Curving
- Convex and concave, horizontal and vertical
- Applications
- Roofing, Wall cladding, Soffits
Concealed
clips.
Each pan is held by stainless steel clips hidden under the seam. A fixed zone holds the pan in place and sliding clips let the rest of it move with heat.
Sliding clip
Lets each pan expand and contract along its length while holding it to the deck.
110 mm base, 70 mm slot, 25 mm tab, 26 mm high
Fixed clip
Locks the pan in place in one zone, so movement runs away from that point.
36 mm wide, 26 mm high, 25 mm base
Details and
drawings.
Typical details for documentation. Select a drawing to view it full size, or download the full detail set.
Parapet capping
Vertical standing seam at a parapet: capping over a continuous folded strip, membrane, top hats and plywood. Minimum 1° fall on the capping.
Roofing Group detail, for illustration only
Standing seam clips
Fixed and sliding clips for double lock and single lock standing seam.
VMZINC drawing, for illustration only
Literature
11 documents
Full detail sets
Eaves, ridge, valley, parapet, corner, window and penetration details as PDF, with the manufacturer data behind them.
Browse the library- Double lock standing seam roof details 01 to 05
- Single lock standing seam wall details 01 to 05
- Standing seam capping detail
- Standing seam fixing clip detail
- Concealed box gutter detail
- Parapet capping detail
- Roofing Group single lock standing seam brochure
- Roofing Group double lock standing seam brochure
- VMZINC single lock standing seam, specification of details
- VMZINC double lock standing seam data sheet
- VMZINC standing seam wind test summaries
How we deliver standing seam
- 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
11 answered
Standing seam 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 standing seam cladding?
Standing seam is a metal roof and wall system made of long pans joined by a raised seam. Concealed clips fix the pans to a continuous deck, so no screws show on the finished surface.
What is the difference between single lock and double lock standing seam?
A single lock seam is folded once to 90°. It suits walls, soffits and roofs steeper than about 25°. A double lock seam is folded twice through 180°, which closes the joint against wind driven rain and suits roofs down to about 3°.
What is the minimum roof pitch for standing seam?
Double lock standing seam is typically used on roofs from about 3°. Single lock seams are only used on roofs steeper than about 25°; below that the seam must be double locked. The exact minimum depends on the metal, the roof length and the manufacturer’s guide, so we confirm it for each project.
What does standing seam need underneath?
A continuous deck. Our standard wall layers are 18 mm structural plywood to AS 2269 on studs or top hats at no more than 600 mm centres, a breathable waterproof membrane, and a 20 mm ventilated cavity behind the plywood.
How far apart are standing seam clips?
Clips go at a maximum of 300 mm centres. They are stainless steel, at least 0.4 mm thick, and include fixed clips that hold each pan in one zone and sliding clips that allow thermal movement.
How wide are standing seam panels?
Standard panel widths are 330 mm for aluminium and Colorbond or UniCote steel, 430 mm for zinc, and 430 or 530 mm for copper. These widths suit the coil widths available and keep waste down. Wider panels are available but can show distortion or oil canning, so we confirm widths in the shop drawings.
Which metals can be used for standing seam?
We fold standing seam in zinc (0.7 mm), copper (0.7 mm), aluminium (0.8 mm) and Colorbond or UniCote steel (0.55 mm). See our materials pages for finishes and colours.
Does standing seam cladding need a flashing where it meets the roof?
Not where the roof is standing seam as well. The wall seams mitre into the roof seams and carry through as one continuous line, with no flashing across the junction. That mitred look is usually the reason an architect specifies the same system on both planes, so we set the pan widths out on the roof and the wall together and resolve the mitre on the shop drawings before anything is folded.
Can standing seam be curved or tapered?
Yes. Pans curve convex or concave down to about a 1.5 m radius, and they can be tapered as well. We curve them in our Sydney workshop for barrel roofs, turrets and sweeping walls, so the panel arrives on site already to the radius rather than being forced into it.
Why does zinc standing seam need a ventilated cavity?
Zinc needs air behind it so moisture can escape from the back of the sheet. VMZINC details a 20 mm unobstructed cavity behind the plywood, formed by battens or top hats.
What warranty comes with standing seam?
All our work carries an 8-year workmanship warranty. Zinc projects installed to VMZINC’s requirements qualify for a 50-year material warranty, and only metal formed in our own facility goes into the system.
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