Derby Market Hall – Preserving heritage through an effective combination of solution and structure
For those of you who are familiar with the city of Derby, you may have noticed a large scaffolding has recently been erected around and inside Derby Market Hall.
Although it may seem like it’s appeared out of nowhere and has been constructed within a matter of weeks, the highly engineered solution is the result of almost three years of careful planning and assessments, designed to accommodate roof renovation works without impacting the building’s existing structure.
Opened in 1866, the Grade II listed building was significantly restored during a multi-million-pound programme of works in the late 1980s and to this day it is still the location of a very active marketplace, featuring a range of small businesses and contemporary stalls.
Offering a range of items, from fresh meat and fish to vintage and designer clothing, Derby Market Hall is a trading location steeped in history and preserving the heritage of the site has been critical throughout the years.
Survey offers valuable insight
When it was announced that new renovation works were planned for the Market Hall, our team of skilled engineers were engaged to conduct a structural survey of the building to assess its current condition and its ability to potentially support additional loads from temporary structures.
Given the heritage of the site, assessments were conducted with the preservation of the building in mind and the survey consisted of a non-intrusive visual examination of the building condition and materials used.
The scope of the survey included identifying load paths, structural form, and stability systems relied upon by the building – all of which was successfully delivered by our team.
While it was important to assess the stability of the building and develop a solution that wouldn’t negatively impact its structure, another key challenge for our team was delivering temporary works that allowed daily activities in the market to continue without unnecessary risk or disruptions.
This meant designing and implementing a scaffolding structure that would allow access to construction workers, while enabling businesses to continue trading as normal.
To achieve this, extensive investigations were carried out across all aspects of the Market Hall, allowing our team to draw a number of conclusions and recommendations that would shape the delivery of the project.
Report shows devil in the detail
In the official report, we recommended that a range of suitable intrusive investigations must first be commissioned if the building were to support additional loads from the temporary structure.
This would deliver safe assessments of the lateral stability of the Market Hall, the condition of existing cast iron structures and examinations of the site’s foundations amongst other important findings.
Although initially it could cost more to design and install, we established an alternative solution which would provide a temporary structure fully independent of the existing building, with no loads imposed on the Market Hall.
Because the integrity of the existing structure could not be validated without significant intrusive investigations, this favoured approach would remove the need for the time-consuming and expensive intrusive investigations, to deliver a more efficient solution.
Alternatively, a more cost-effective solution could be to have an independent temporary structure that relies on a number of intermediate supports within the footprint of the Market Hall, reducing the span of the structure and making it easier to install.
Our in-depth survey also revealed the existing structure relies on notoriously brittle cast-iron columns for support, which can fail catastrophically through the slightest impact from a powered vehicle.
For this reason, we advised the contractor to take appropriate steps to provide protective barriers to these columns if such machinery was being used within the building.
All these findings, conclusions and recommendations were the result of many months of careful examinations, delivered by our experienced team of engineers.
While on the face of it, it may just look like a simple scaffolding structure, in fact there’s a significant amount of detail and strategic planning that goes into delivering temporary works.
Combining solution and structure is an art that we understand better than most and using our expertise we were able to finally deliver a solution that fit the specification of the project.