When modern repairs go wrong in historic homes
During a recent residential building survey in Nottingham, I inspected a period property that, on the surface, appeared to have been well maintained. The exterior brickwork had been repointed, the walls looked neat and uniform, and there were clear signs of recent improvement works.
However, as is often the case with historic buildings, a closer inspection told a very different story.
What initially looked like “good maintenance” was, in fact, causing long-term damage.
Cement repointing to solid brick walls
The property was a traditional late Victorian terrace, constructed using solid brick walls and originally built with lime mortar. At some point in recent years, the external walls had been repointed using a hard cement-based mortar.
This is a very common alteration seen across Nottingham’s period housing stock.
While cement mortar can look tidy and durable, it behaves very differently from traditional lime mortar. And in historic buildings, that difference matters.
Why lime mortar is so important
Lime mortar plays a crucial role in how older buildings manage moisture. It is softer and more breathable than modern cement, allowing moisture to evaporate naturally from the wall.
Cement mortar, by contrast, is dense and impermeable. When used in historic construction, it can trap moisture within the brickwork rather than allowing it to escape.
Over time, this can lead to a range of issues.
What was happening at the property
At this particular property, several problems were already developing:
Moisture was becoming trapped within the external walls
Internal plaster was showing early signs of dampness
Brick faces were beginning to deteriorate
The mortar itself was cracking away from the brick edges
Rather than protecting the building, the cement pointing was accelerating decay.
This is a classic example of modern materials being incompatible with traditional construction.
The hidden risk to brickwork
One of the most significant risks with hard cement mortar is that it forces moisture to escape through the bricks instead of the joints.
Historic bricks are often softer than modern ones. When moisture repeatedly freezes and expands within them, the surface can break down.
In many cases, the brick suffers more damage than the mortar itself.
Why these repairs are so common
Inappropriate repointing is something I encounter regularly when carrying out residential building surveys of historic homes in Nottingham.
There are a few reasons for this:
Cement is widely available and commonly used in modern construction
It is often seen as a “stronger” or more permanent solution
The importance of breathability in older buildings is not always understood
Previous repairs may have prioritised appearance over performance
Unfortunately, these well-intentioned repairs can create more problems than they solve.
Putting it right
The solution is not always immediate or straightforward. Removing cement pointing from historic brickwork must be done carefully to avoid further damage.
In this case, the advice provided included:
Gradual removal of inappropriate cement mortar
Repointing using a suitable lime-based mortar
Allowing the building to dry naturally over time
Monitoring internal moisture levels following repairs
This type of work is best carried out by contractors experienced in traditional materials and heritage properties.
A wider lesson for owners of period homes
This example highlights a broader point: maintaining a historic building is not just about keeping it looking good. It is about using the right materials and techniques so that the building can function as intended.
Modern solutions are not always better, particularly when applied to traditional construction.
Final thoughts
Historic homes in Nottingham are remarkably durable, but they rely on a balance of materials that has developed over time. Disrupting that balance, even with well-meaning repairs, can lead to unintended consequences.
A specialist residential building survey helps identify where this has happened and provides practical guidance on how to address it properly.
Understanding the building is always the first step to looking after it.