Lead Flashing Around Chimneys Derby — Repair or Replace

Call: 01332-529704

A chimney with failing lead flashing rarely announces itself with a dramatic leak on day one. It starts as a lifted edge, a hairline crack, or a mortar chase that’s gone soft, and it works quietly behind the tiles until damp shows up on a chimney breast or ceiling below. We inspect and repair chimney lead flashing across Derby and Derbyshire every week, checking all four parts of the system — apron, soakers, step flashing, and back gutter — rather than patching the one visible symptom.

• Own Team, No Subcontractors
• IPAF & PASMA-Certified Access
• Free Drone Survey Available
• Free Quotation, No Obligation

All four parts must be present and correctly fitted. If any one of them fails, the whole system is at risk. Lead is the gold standard for chimney flashing in the UK because it flexes with temperature changes, resists corrosion, and — when installed correctly — lasts 50 to 70 years. Derby’s large stock of Victorian and Edwardian terraced housing means many chimney stacks sit mid-slope on clay tile roofs, putting the back gutter under heavy water load every time Derbyshire gets prolonged rainfall — which makes correct installation, and the right lead code for each component, critical.

From inside the loft:

• Daylight visible around the chimney brickwork at roof level
• Damp staining or tide marks on chimney breast timbers
• Wet or soft timber at the rear of the stack — a strong sign the back gutter is failing

Inside the house:

• Damp patches or brown staining on the chimney breast wall
• Watermarks or staining on ceilings directly below the chimney
• Peeling wallpaper near the fireplace, particularly on upper floors

Homeowners across Chaddesden and Spondon regularly contact us after spotting these internal signs first — the chimney stacks on the DE21 terraced housing stock are often carrying original lead that has never been replaced. If your home was built before 1970 and the flashing has never been touched, a professional inspection is overdue.

Saturated mortar: After days of wet weather, the mortar around the flashing chase becomes waterlogged. Even with no visible gap, water wicks through the joint and into the roof structure — which is why a chimney leak can creep up gradually rather than appearing all at once. It is also worth checking beyond the flashing: water at the chimney breast can also come from cracked or missing flaunching around the chimney pot, failed pointing on the stack brickwork, a missing or broken chimney cap, or porous brickwork absorbing water directly through the stack face. We check all of these during every inspection — not just the lead.

Full replacement is needed when:

• The lead shows widespread cracking, thinning, or corrosion across more than one component
• Previous repairs have been made with bitumen tar, sealant, or mortar fillet — these materials cannot flex with the lead and will keep failing
• The original installation was never a complete system — soakers missing, back gutter absent, or lead chased in incorrectly
• The flashing is original to a 1960s or 1970s build and has never been replaced

In Littleover and Mackworth, we frequently work on post-war semi-detached properties where the original leadwork is well past its service life — on roofs of that age, a full re-lead is almost always the better investment. One point worth knowing: replacing the flashing does not mean replacing the chimney. The leadwork is completely independent of the stack. In most cases we lift the surrounding tiles, re-lead, and relay — without touching the brickwork above.

Back gutter is the lead channel at the rear of the chimney — the uphill face that takes the greatest volume of water running down the roof slope. It is the component that fails most often and is the most frequent cause of chimney leaks; we use Code 5 lead for back gutters because of the water volume this area handles. Apron flashing covers the front lower face of the chimney where it meets the tiles and is generally the last component to fail. On chimney stacks in Darley Abbey and Park Farm — where slate roofs are more common — soakers are always required alongside step flashing. When we quote for a chimney re-lead in Derby, all four components are included as standard.

Signs your chimney has cement fillets rather than lead:

• A grey or white mortar band running around the base of the chimney stack
• No visible strip of lead along the chimney sides or front face
• Cracks or gaps in the mortar join between the stack and the tiles

When we replace a cement fillet, we remove all old mortar, cut proper chases into the brickwork, and install a full Code 4/5 lead flashing system — soakers, step flashing, apron, and back gutter. This is not a patch repair — it is the correct installation that should have been done originally, and it will outlast cement fillet by several decades.

Working at height safely also requires proper equipment and risk management. A chimney flashing job is not a ladder-and-hope situation — it requires correct access and, on taller stacks, scaffolding. Our own IPAF and PASMA-certified team members handle this directly.

1. Call and free inspection: You get in touch describing what you’ve noticed — a leak in heavy rain, damp staining, or a concern flagged by a surveyor. We book a free inspection, with a drone survey available where it helps get a clearer look at the stack.
2. Checking all four components in turn: We look at apron, soakers, step flashing, and back gutter one by one, from ground level, from inside the loft, and inside the house if there’s staining, rather than stopping once we’ve spotted one obvious cause. Flaunching, pointing, and the chimney cap get checked at the same time, since they can cause the same symptoms.
3. Access arranged for the stack: Low, accessible chimneys can often be reached by ladder with the right equipment. Taller or steeper stacks need scaffolding or tower access, which our IPAF and PASMA-certified team members handle directly rather than waiting on a hired-in crew.
4. Repairing or re-leading component by component: Where the apron or step flashing has lifted but the rest is sound, we re-dress or renew that section alone. Soakers are replaced individually as the tiles are lifted. A failing back gutter is rebuilt in wider Code 5 lead rather than patched over. Where more than one part has failed, we replace the whole system together, using the correct lead code for each component.
5. Completion and explanation: We leave the site tidy and talk you through which of the four components were repaired, which were left as they were, and anything else worth watching, such as flaunching or pointing due for attention separately.

• Rebuilding or repointing the chimney stack brickwork itself — only carried out if flaunching or pointing has separately failed
• Scaffolding or tower access on taller or steeper stacks — assessed and costed separately once we’ve seen the roof
• Internal replastering or redecorating once damp-affected areas have dried out
• Chimney pot replacement, unless agreed as part of the same job
• Sealant or bitumen tar ‘quick fixes’ — we don’t offer these as they fail within months and cost more in the long run

Price follows the scale of work needed on each of the four components rather than a flat rate. A localised repair to step flashing or a single soaker sits at the lower end, since it’s often a case of lifting a few tiles and re-dressing lead that’s already there. Apron replacement is usually mid-range, depending on the width of the stack. A back gutter rebuild tends to cost more, because it’s built in heavier Code 5 lead and often means dismantling and reforming the box behind the chimney rather than just re-dressing a surface. A full re-lead covering all four parts, especially one that starts with stripping out an old cement fillet, sits at the top of the range. We give a written quote after the free inspection — including drone survey where it’s useful — so the figure reflects which of the four components your chimney actually needs work on rather than a generic estimate.

We fit the correct lead code for each part — Code 4 for apron, soakers, and step flashing, Code 5 for back gutters — rather than whatever’s cheapest, and we don’t patch a failing component with sealant or bitumen tar as a short-term fix. Every enquiry gets a free inspection, with a drone survey available, before any work or quote is agreed. Most of our chimney lead flashing jobs are within Derby itself — Allestree, Mickleover, Oakwood, Chaddesden, Spondon, Littleover, Alvaston, Chellaston and the streets around the city centre — and further out we regularly work across Derbyshire in Belper, Duffield, Ripley, Heanor, Ilkeston, Long Eaton, Swadlincote, Ashbourne, and Matlock.

Derby Roofers proudly serves homeowners and businesses throughout Derby city and the wider Derbyshire area. Our local teams cover all of Derby city and the surrounding towns and villages below — not sure if we cover your area? Call us on 01332-529704 and we’ll be happy to help.

A leaking chimney does not fix itself — and the longer it is left, the more it costs to put right. Water that starts as a small gap in the flashing will eventually soak into roof timbers, rot the back gutter board, stain your chimney breast plasterwork, and work its way into ceiling joists. What starts as a straightforward lead repair becomes a much larger job.

At Derby Roofers, we inspect chimney lead flashing across Derby and Derbyshire and give you a straight answer — repair or replace, what is involved, and how long it will last. We carry out all leadwork ourselves, use the correct lead codes for every component, and do not patch over problems with sealant.

• ✅ Free inspection and free drone survey available
• ✅ Own team carries out all leadwork — no subcontractors
• ✅ IPAF & PASMA-certified access on taller or awkward stacks
• ✅ Correct lead code for every component, every time

If your chimney is leaking, or you have not had your flashing inspected and your home was built before 1980, call us today.