The short answer
Yes, lead flashing can often be repointed. Where the lead is sound but the mortar in the chase has crumbled, the roofer rakes out the old joint, wedges the lead and points it again. If the sheet is cracked, thin or has slipped badly, refixing or replacing the lead is the better answer, because new mortar cannot mend a split.
What the pointing at the chase is doing
Where a roof meets a brick or stone wall, the flashing lead has to be held against the masonry. The usual method is to cut a groove along a mortar joint, which is called the chase, push the top edge of the lead into it, wedge it, and fill the groove with fresh mortar. That mortar does two jobs. It stops water running down the wall and getting behind the lead, and it locks the wedges so the sheet cannot slip out.
Because the groove sits on the weather side of the wall, no joint on the house gets a harsher soaking from rain, frost and sun. Rain, frost and sun work on it every year, and a joint that was sound at fitting will not stay that way forever. Pointing is also the part of a flashing you can often see from the garden, so it is usually the first fault anyone notices.
How you can tell the pointing has failed
Standing at ground level, look along the line where the flashing meets the wall. Mortar that has gone sandy, crumbled or fallen out in places leaves a dark gap. Lead that stands proud of the wall instead of lying tight against it has lost its wedges. A damp patch on the wall inside, level with the roof line, or a stain on the ceiling below a chimney, points the same way.
A ladder is the wrong tool for this inspection when you are not trained to use it on a roof edge. A roofer can lift the edge of the lead gently and see what is behind it. Sometimes the lead has dropped only a short way. At other times a whole length has slipped and rain has been running behind it for some time, and the timber beneath may be wet. The survey photographs show which of these it is, close up, with the written quote to follow.
Why a loose flashing gets worse if it is left
A flashing with a gap behind it does not fail all at once. Water finds the slot, runs down the back of the lead and soaks into the brickwork and the roof timbers near the wall. Wet timber at the wall plate or the rafter feet can rot slowly, and the damage is out of sight until a stain appears. In winter the water freezes in the joint and pushes the mortar further apart, so the next shower finds an even bigger gap.
A short length of loose lead is also easy for wind to catch. Once an edge lifts, the gusts do the rest, and a repointing job becomes a refixing one, or a replacement. Dealing with the pointing early is nearly always the cheaper course. Our lead roofing pages cover the other details that sit beside a wall flashing.
What a proper repointing involves
The old mortar is raked out of the chase to a clean depth, taking care not to damage the brick. The lead is checked along its whole length for cracks and for any fold that has opened. If it is sound, fresh lead wedges are tapped in at regular intervals to hold the top edge, and the groove is pointed with mortar that suits the wall. Our page on lead flashing wedges explains why wedges, not sealant, do the holding.
Mortar choice matters. A hard cement mix pushed into a soft old brick joint can crack the brick edges and shed within a few seasons, so the mix should be compatible with the masonry. Pointing lead with sealant alone, with no wedges, leaves nothing mechanical holding the sheet, and it tends to fail when the sun and cold work the lead back and forth.
Matching the mortar to old and new walls
The mix that goes into a chase has to suit the wall around it. Brickwork built in the last century or so, with hard bricks and cement joints, takes a cement-based mortar without complaint. An older wall, with soft bricks or stone laid in lime, wants a softer mortar so the joint wears before the masonry does. Pushing hard cement into a soft wall can chip the brick arrises, trap water and shed within a few seasons.
Colour and finish matter on a visible chimney or gable, because a bright new line of pointing looks like a scar. Swindon Borough Council's planning team is the place to ask about protected buildings, since the mix and finish of visible pointing can matter there.
When refixing or replacing is the better answer
Repointing is the right answer only when the lead underneath can still do its job. If the sheet is split along a fold, worn thin or pulled out of shape, new mortar covers a defect that will keep leaking. In that case the lead is lifted, repaired, relaid or replaced, and the chase is pointed afterwards. A run of lead that has slipped but is otherwise good can be refixed and wedged without buying new sheet. Our page on lead flashing repairs covers the range from patching to replacement.
Sheet length matters on long walls too. Lead is laid in lengths with laps between them, because it moves with the weather, and an over-long piece is likely to split. Our page on lead sheet lengths covers how long a piece should run.
Cost, access and next step
MyBuilder's chimney repair guide, updated in August 2026, puts chimney repointing at around £750, in a range of £500 to £2,000, and a chimney flashing repair at £250 to £1,200. Those are national typical figures, and your price depends on how much wall is involved, how high it sits and whether a scaffold or tower is needed. Make sure each figure you compare counts VAT and scaffolding in the same way.
Where the lead is sound and the mortar is what failed, our recommendation is repointing and not a new flashing, because that is the job that fits the fault. We send the written quote once the survey is done, and the workmanship is guaranteed for a decade, in writing. Phone 01793 626096 or send a message on WhatsApp.