Chimney Repointing Malvern

Chimney repointing renews the mortar joints between the bricks of the stack, which are the most weather-beaten masonry on any building. We rake out the failed mortar, brush the joints clean, and repoint in fresh mortar of the correct type and colour. Where the flaunching — the mortar collar around the pots — has cracked, we renew that too, and we fit or replace cowls and caps as needed.

The choice of mortar is not a detail. On pre-1920 Malvern properties we use hydraulic lime, which is softer than the Victorian brick and erodes sacrificially over decades as it is meant to. On modern stacks we use an appropriate sand and cement mix. Using cement on a Victorian chimney is a common and damaging mistake, and it is one we never make.

Malvern's chimneys weather harder than those in sheltered towns, and the reasons are specific to the local geography and building stock.

The exposure comes first. Stacks on the hillside streets of Great Malvern and up towards Malvern Wells take the full force of the prevailing south-westerly weather as it accelerates over the ridge. The west and south-west faces of these stacks erode faster than the sheltered faces, which is why we always assess all four faces of a stack rather than quoting on the one visible from the ground.

The building era comes second. The Victorian and Edwardian villas of Great Malvern were built with soft handmade brick and lime mortar, and many carry two, three or even four stacks each. That is a lot of exposed masonry per property, all of it now 120 to 160 years old and much of it never repointed. Where previous owners or contractors have repointed these stacks in modern cement, the damage is often worse than if they had been left alone, because the hard cement has forced the soft brick faces to spall. Putting that right — raking out cement and repointing correctly in lime — is a regular part of our Great Malvern chimney work.

The choice between lime and cement mortar is the single most important decision on any Malvern chimney repointing job, and getting it wrong causes more damage than leaving the chimney untouched. The principle is straightforward: the mortar should always be softer than the brick around it, so that as the joint weathers over decades it is the mortar that erodes and is renewed, not the irreplaceable historic brick face.

On the Victorian and Edwardian chimneys that dominate Great Malvern, the brick is soft handmade stock and the original mortar was lime. Repoint such a stack in modern portland cement — which is far harder than the brick — and the weathering forces reverse: instead of the mortar giving way, the brick faces spall and crumble, permanently disfiguring the stack and opening new paths for water. We see the results of this mistake regularly on Great Malvern stacks that well-meaning owners or cheap contractors have repointed in cement, and putting it right means raking the cement out and repointing correctly in hydraulic lime. On post-1920 stacks built with harder brick, an appropriate cement mix is fine. Matching the mortar to the era is not pedantry — it is the difference between a repair that lasts and one that actively destroys the chimney.

When Repointing Is Not Enough

Repointing renews the surface mortar between the bricks, and on a stack whose brickwork is otherwise sound that is all that is needed. But on the oldest and most exposed Malvern stacks — particularly the tall multi-flue chimneys on the exposed hillside villas of Great Malvern and Malvern Wells — the damage sometimes runs deeper than the joints. Where frost and a century of weather have caused the bricks themselves to spall and crumble, or where a stack has begun to lean, repointing alone will not fix it and a partial or full rebuild is the honest answer. We assess this properly during the survey, checking not just the joints but the condition and alignment of the brickwork, so that we recommend the right level of work rather than repointing a stack that needs rebuilding. Where a rebuild is required we reuse sound salvaged brick and match the rest, keeping the appearance correct on a period property.

If the problem is a leak rather than eroded pointing, it is usually the lead flashing or flaunching — covered on our chimney repairs and leadwork pages. For the causes of chimney damp specifically, see our guide to chimney leak causes in Great Malvern.