Stone and brick restoration across North London

The building stock

North London's character is defined by its Georgian and early Victorian terraces. Canonbury, Barnsbury, and Cloudesley Square in Islington are among the finest intact Georgian streets outside Bath. Highgate and Hampstead have a mixture of Georgian detached villas and later Victorian mansion stock. Stoke Newington and Finsbury Park contain a high density of mid-Victorian terrace housing, much of it in conservation areas.

The predominant materials are Portland stone for civic and ornamental work, London stock brick for the terrace stock, and limestone for decorative elements. There is also a significant amount of Roman brick visible in foundations and boundary walls across the area, particularly in properties close to the Roman road alignments.

What we do in North London

DOFF steam cleaning is our most common method across North London. The London stock brick used in the Victorian terrace stock responds well to superheated steam, and it is the one method that Historic England consistently endorses for listed domestic buildings. Pressure washing damages the brick's fire skin irreversibly. Acid attacks the calcium carbonate in the mortar joints and can dissolve the brick itself if left too long. Steam at the right temperature lifts soiling without touching the substrate.

For Portland stone facades, our approach depends on the nature of the soiling. Black sulphate crust that has built up over decades is best addressed with TORC vortex cleaning, which introduces a fine calcium carbonate aggregate in a controlled vortex and removes the crust without abrading the stone surface. Lighter general soiling responds to DOFF alone.

Repointing is frequently required following cleaning. Many North London properties have been repointed with hard OPC (ordinary Portland cement) mortar at some point in the twentieth century, often in the 1960s or 70s. Cement mortar is stiffer than the original lime, cannot accommodate the movement the building needs, and traps moisture in the masonry behind it. We remove it, usually with a carefully controlled angle grinder or oscillating tool, and repoint with a non-hydraulic or feebly hydraulic lime mortar matched to the original.

Areas we cover

• Islington
• Camden
• Highgate
• Hampstead
• Stoke Newington
• Finsbury Park
• Crouch End
• Archway
• Tufnell Park
• Kentish Town
• Holloway
• Muswell Hill

Listed buildings and conservation areas

Islington has one of the highest concentrations of listed buildings in Inner London. The London Borough of Islington's conservation team is experienced and engaged, and they require a method statement and Conservation Officer pre-approval for most cleaning works to listed buildings. We prepare these documents as a matter of course and liaise directly with the relevant officer. There is rarely a need for the client to manage this process themselves.

Camden's conservation areas cover the majority of the borough's Victorian building stock. Works that materially alter the appearance of an unlisted building in a conservation area require permitted development consideration. We assess this on a project-by-project basis and advise accordingly.