A standing seam clip is a small fixing piece — usually a tab of zinc sheet — nailed or screwed to the substrate to hold zinc bays, gutter linings and metal roofing in place. One edge of the clip is turned over slightly, and the edge of the sheet — the inside of the bead or the seam — hooks behind it. The Dutch term is klang, the German Hafte.
The point of the arrangement is this: the fixing is held firmly by the substrate, but the sheet itself is never pierced. That keeps the covering watertight and lets the metal keep moving. Zinc expands measurably as it warms; a sheet screwed straight through would split or ripple.
Types
| Type | How it works |
|---|---|
| Fixed clip | Holds the bay at one point; takes load but allows no movement |
| Sliding clip | Two parts that slide over one another, allowing lengthwise expansion |
| Hook clip | Stops the covering slipping down on vertical or steep surfaces |
On a standing seam or batten roll roof, fixed and sliding clips are combined to a set pattern: fixed where the bay has to stay anchored, sliding over the rest of its length.
Where they are used
- Standing seam roofs and zinc bays — the clips are nailed to the roof decking and folded into the seam
- Zinc gutters and gutter linings — clips hold the bead or the top edge of the lining
- Valleys and roof edges — when finishing hips, edges and abutments
Points to watch
- Metal compatibility — use clips of the same or a compatible metal; copper in contact with zinc corrodes the zinc
- Number and spacing — how many clips per metre, and how fixed and sliding clips are distributed, is not a matter of feel; follow the zinc supplier’s instructions and the applicable trade rules for metal roofing
- Substrate — nail or screw into sound, dry decking; no clip holds in decayed timber
- Do not block the movement — a rigidly held sheet that cannot expand will split or rattle; allow the movement deliberately, through sliding clips
Related terms
- Zinc sheet
- Roof decking
- Roof covering
- Gutter
- Valley
- Cleat
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