Do lead flashings need clips?

A clip is a narrow strip of lead, or a similar strip, fixed to the roof or wall at one end and folded around the lower edge of the flashing at the other. It holds the edge down against the surface beneath, so the lead cannot lift or flap, yet the sheet can still slide a little as it warms and cools.

That balance is the whole idea. If the lower edge were nailed down hard, the lead would tear as it moved. If it were left completely free, the wind would lift it. A clip does neither. It grips the lead lightly and lets the metal expand and contract beneath it. For the way the top edge is fixed, see our answer on lead wedges, which pairs with this one. Between them, the two fixings hold a flashing at both ends while leaving the middle free to move. Without that give, the sheet either lifts or splits, and either way the flashing stops doing its job.

Clips go on the free lower edge of a lead apron below a chimney or dormer, on the bottom edge of a cover flashing, and on stepped flashings and lead-covered areas that finish in a drip or overhang. Anywhere that a piece of lead hangs free on its lower side is a place that needs holding in the wind.

They are spaced at intervals along the edge, closer on exposed work and at corners where the wind catches the edge first. On an apron flashing, the clips lie hidden beneath the lead and are seldom seen once the job is done, which is why people rarely ask about them until a flashing has already lifted. A long run of lead along a sheltered wall needs fewer than the same length on a corner facing the sea. Lead on a dormer cheek or the side of a bay is clipped in the same way as an apron, since the edge hangs free there too.

Near the Channel, a gale will find any loose edge. A flashing without clips can lift at the lower edge, flap against the roof and fold back on itself. Lead that has been flexed that way work-hardens and cracks, and the crack often runs along the fold, where you cannot see it from the ground.

Once the edge has lifted, rain can be driven under it. The first sign inside the house is usually a damp patch or stain near the chimney or wall, after wind and rain together. Sealant smeared along the edge may hide the lift for a season, but it does not hold the lead down, and it makes the true fault harder to read. A flashing that has flapped for several winters is often too work-hardened to be flattened and refixed, and it may need replacing. If you hear lead rattling in a blow, that is the edge moving, and it is worth having someone look at it before the next storm.

Because clips are hidden, the way to check is to ask. A roofer who fits them will say so and can show it on the survey photographs or the photographs taken during the work. You can also look at the finished edge: it should lie flat and snug on the surface below, with no gap you can slip a finger under.

If you are replacing the flashing and want a second opinion, ask for the method to be written down, including how the top is fixed, how the bottom is held and how the sheets are lapped. Our lead flashing guide explains the full sequence, and the lead roofing and leadwork page covers the wider work. Repeat visits to the same flashing are a clue that the fixing was never right. A neat edge on its own proves little, as a lifted flashing can be pressed flat for a photograph, so ask how it is held as well.

Ask three things. How is the top edge held, how is the bottom edge held, and how does the lead move? Good answers mention wedges at the top, clips at the foot and laps or rolls between lengths. A vague answer suggests the detail has not been thought through, and it is worth asking again, politely, until you hear it described.

The fixing method does not usually change a price much, but a flashing built without it can cost far more to redo. After the survey, a quote in writing gives one total, and the method is described in it. On a repair, we photograph the lifted edge as it was found, so you can see what we saw. Ask for the same on any job where lead is renewed. That small habit of asking tells you quickly whether the roofer understands the details that decide how long leadwork lasts.