When your chimney deteriorates, the risks extend beyond appearance. Damaged masonry, failing flashings or blocked flues can lead to damp ingress, heat loss, carbon-monoxide risks and, in severe cases, fire. Across England there were 26,491 dwelling fires in the
year ending June 2023, underscoring why routine inspection and swift repair of combustion and ventilation systems matter.
Why Bexley Homes Need Proactive Chimney Care
Bexley’s housing mix includes a significant proportion of pre-war and post-war properties across areas such as Bexley, Sidcup, Welling and Bexleyheath. Older stock often features traditional brick stacks, lime mortars and lead flashings that naturally weather over decades. London as a whole has an older housing profile than much of England—around half of homes were built before 1945—so age-related chimney wear is common.
Weather accelerates the cycle of freeze-thaw and expansion around exposed rooflines. Long-term Met Office climate data for the London area shows annual precipitation broadly in the 600–800 mm range, meaning repeated wetting and drying of mortar beds and lead interfaces. Over time this movement opens capillary paths for water, leading to staining, damp ceilings and timber decay around the chimney breast.
What We Repair
1) Chimney repointing and brick replacement.
Open joints, spalled bricks and failing crowns let water migrate into loft spaces. We cut out perished mortar, repoint with compatible mixes (lime or cement as appropriate), and replace damaged units to restore structural integrity and weathering.
2) Lead flashing and step flashing renewal.
Lead is the primary water barrier where chimney meets roof. Split or lifted flashings are the most frequent cause of chimney leaks we see in Bexley terraces and semis. Our team forms and dresses new code-graded leadwork and installs appropriate soakers and chases for a durable seal.
3) Flue terminals, cowls and ventilation.
Incorrect or missing terminals can cause downdraft, bird entry and moisture build-up. We fit anti-downdraft cowls, bird guards and ventilated caps tailored to appliance type and flue condition.
4) Chimney pots and crowns.
Cracked pots or failed crowns channel water directly into the stack. We replace pots, rebuild crowns and add drip edges to shed rain effectively.
5) Chimney removal and making-good (where appropriate).
For redundant stacks causing persistent issues, we provide safe partial or full removals with structural making-good—always subject to survey and necessary consents.
Safety and Compliance
Chimney works must align with Approved Document J of the UK Building Regulations, which governs flues, combustion air, separation distances and materials. New or altered chimneys should also meet relevant NHBC technical standards on stability and fire safety for new-build acceptance. Positive Roofing plans and executes repairs to reflect these benchmarks, coordinating with your stove engineer or Gas Safe professional where needed.
Safety at height is non-negotiable. Falls from height remain the leading cause of workplace fatalities in Great Britain, accounting for over a quarter of deaths in 2024/25—one reason to choose accredited, insured roofers with rigorous method statements.
Our Process
Survey and diagnosis.
We conduct a roof-level and loft-space inspection to identify the true failure point—be it flashing, mortar, crown, or flue terminal—and to note any secondary damp paths.
Transparent quotation.
You receive a clear scope of works, materials specification (e.g., lead codes, mortar type), programme and warranty terms.
Remedial works.
We erect safe access, protect adjacent roof coverings, complete repairs in a methodical sequence, and photograph progress so you can see exactly what was done.
Hand-over and aftercare.
We provide guidance on maintenance intervals, appropriate fuel use and ventilation—simple steps that reduce soot, moisture and thermal stress on your chimney. The London Fire Brigade highlights the ongoing risk profile associated with domestic heating; sensible usage and regular checks materially cut that risk.
Indicators You Need Chimney Repairs
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Water staining on chimney breasts or ceilings near the stack
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Moss growth and salt (efflorescence) on brickwork
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Crumbling mortar, loose haunching or a rocking pot
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Persistent “mystery leaks” despite previous roof patching
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Soot smells, downdrafts or bird activity around the pot
If any of the above are present, early intervention is cost-effective. Minor repointing and flashing renewal often avert major plaster, timber and insulation damage.
Why Choose Positive Roofing in Bexley
Local expertise. We work daily across Bexley, Sidcup, Welling, Bexleyheath and surrounding districts, familiar with typical stack details on local stock—from 1930s semis to Victorian terraces.
Technical quality. Our teams use compatible mortars, correct lead codes, and best-practice chase details to maximise service life.
Evidence-based recommendations. We link repair scopes to regulatory requirements and the building’s age and exposure, not just symptoms, so you receive durable solutions rather than temporary patches.
Safety first. Comprehensive RAMS, appropriate access and a clean, respectful site are standard.
Book a Professional Chimney Inspection
With older housing common in Bexley and London’s steady annual rainfall exposing rooflines to continual weathering, timely chimney maintenance is prudent. Whether you need targeted repointing, new flashings or full stack remediation, Positive Roofing delivers safe, compliant and long-lasting chimney repairs tailored to your property. For a detailed survey and fixed quotation, contact our team today.