Chimney repairs in Cosham — repointing, lead flashing, stack rebuilds and pot replacement. Cosham's 1930s semis have chimney stacks that are now 85–90 years old.
Lead flashing failure, ridge mortar deterioration and pot haunching failure are the most common chimney calls from Cosham. We assess the full stack on every job not just the reported failure point.
Repointing is appropriate where brick faces are intact and only mortar joints have failed. Rebuilding is required where bricks have spalled, the stack has leaned or structural movement is present.
Correct lead code for the exposure position is specified on every Cosham chimney job. Heavier code on harbour-facing and seafront elevations. The additional cost is modest against the extended replacement interval.
Cosham's 1930s semis have chimney stacks that are now 85–90 years old. The original lime mortar has generally failed and the correct replacement is a breathable lime-based mix — OPC cement on 1930s soft brick will cause spalling within 10–15 years. The most common calls we receive for chimney work in Cosham are lead flashing failure, mortar joint deterioration and pot haunching failure. We assess the full stack on every chimney job — treating only the visible failure while leaving secondary damage unaddressed is a false economy.
Repointing is appropriate where the brick faces are intact and only the mortar joints have failed. Rebuilding is required where bricks have spalled, the stack has leaned or water has penetrated the core. We assess this honestly on survey — a stack that needs rebuilding will not be quoted as a repointing job.
For Cosham standard positions we specify code 4. For exposed north and west elevations facing the A27 corridor we specify code 5. We specify the correct lead code for the exposure position — heavier code on coastal and harbour-facing elevations. The additional cost of heavier lead is modest against the longer replacement interval it provides.
| Service | Cost Guide | Notes |
|---|---|---|
| Chimney repointing | £250–£650 | Full extent assessed on survey |
| Lead flashing replacement | £400–£800 | Correct code for exposure |
| Pot and haunching | £150–£350 | Replacement pot included |
| Partial stack rebuild | £800–£1,800 | Up to 1 metre |
| Full stack rebuild | £1,500–£3,500 | Includes scaffold |
"1930s semi on Drayton Lane — re-roof the second time for this property. Portsmouth Roofing was honest that the tiles were past repair and specified the right modern equivalent. No pressure, good advice."
"Nail sickness on our post-war Cosham property. Both main slopes assessed and re-fixed with stainless. Explained exactly what nail sickness means and what to watch for."
"Flat roof on our 1970s rear extension — GRP in a day. They matched the upstand height to the existing brickwork exactly. Neat finish."
Yes — Cosham is within our core service area. Call 0239 307 1334 for availability and free quote.
Yes — free, no-obligation survey and written quote before any work starts. No call-out fee.
Yes. NFRC registration, full public liability insurance and 10-year written guarantee on all work.
Most jobs are surveyed within 48 hours and started within 1–2 weeks. Emergency work is available same day — call 0239 307 1334.
Yes where appropriate — Victorian and Edwardian chimneys in Cosham require lime mortar, not OPC cement. Hard cement on soft brick causes spalling. We specify the correct mortar for the chimney age and construction.
Yes — shared party wall stacks are one of the most common chimney jobs in Cosham's terraced streets. We coordinate with both households and price the full stack, not just one side.
Yes — from £350. Capping an unused stack properly prevents water ingress and is significantly cheaper than repairing the damp damage that results from an open stack.
No call-out fees. No obligation. Local Portsmouth roofers covering this area.
0239 307 1334