A standing seam is a watertight joint between two metal sheets, made by folding both edges several times and hooking them into each other. The standing seam — also called folded seam — is mainly used on metal roofs and façades of zinc, copper, aluminium or titanium-zinc. It is a centuries-old technique that plumbers and zinc workers apply by hand or machine.
Types of folded seams
In construction practice several seam types are distinguished:
Single standing seam
- Height around 25 mm — for roofs with sufficient pitch
- Two-step folding to an upright seam
- Standard for roof cladding
Double standing seam
- Height around 25–38 mm — extra watertight
- Four folds for complete clamping
- For lower pitches (from about 7°)
Lying seam
- Horizontal connection between bays below each other
- Combined with standing seams into a diamond pattern
Corner and ridge seam
- For connections at roof edges, ridges and corners
Application
Standing seams are used for:
- Zinc roofing — classic on steep and curved roofs
- Copper roofing — monumental buildings, churches and towers
- Metal façade cladding — sleek modern architecture
- Gutters and drips — watertight plate connections
- Connections around roof penetrations — flexible edge detail
The major advantage of the standing seam: the joint needs no solder or sealant. The mechanical clamping creates a strong, durable and thermally flexible seam — important because metal expands and contracts with temperature.
Related terms
- Zinc
- Roofing
- Lead
- Gutter
- Drip edge
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