Matthews & Roberts Appointed Temporary Works Consultant on Major M56 Infrastructure Project

Matthews & Roberts has been appointed Temporary Works Consultant on a major infrastructure project on the M56. The appointment covers the management and coordination of temporary works for the conversion of three barns predating 1800, which form part of the wider scheme.

The conversion involves structural alterations to all three buildings. The temporary works required to carry them out safely span several design check categories and several different parts of each structure. Our role is to put a clear process around that work so every item is properly briefed, designed, checked, installed and controlled from start to finish.

Scope of the appointment

The appointment covers the full temporary works process for the barn conversions in line with BS 5975:

• Establishing the temporary works procedure and register for the three structures
• Preparing and reviewing design briefs based on survey and condition information
• Assigning design check categories and managing independent checks where required
• Coordinating temporary works designers with the permanent works designer
• Controlling permits to load and permits to dismantle
• Site verification of installed temporary works against approved designs
• Managing interfaces between the barn works and the wider infrastructure scheme

Why structures of this age need a different approach

Barns built before 1800 were not designed to any recognised structural code. They were built by eye and by experience, then altered, repaired and extended over the following centuries. That history matters when they are opened up.

Walls are often solid or rubble filled masonry bedded in lime mortar, with an inner core that may be weaker than the faces suggest. Roof structures rely on timber trusses and frames that may have been cut, patched or reused. Foundations are often shallow or absent. Load paths are rarely what the drawings show, because in many cases there are no original drawings at all.

For temporary works this means the design brief is only as good as the information behind it. Measured surveys, condition surveys and targeted opening up are needed before designs are finalised. Assumptions about wall strength, timber condition and bearing capacity have to be tested, not accepted.

Structural alterations and the temporary works they require

Converting agricultural buildings for a new use involves alterations that each carry their own temporary works:

• New and enlarged openings. Forming openings in load bearing masonry needs needling and propping designed around the real strength of the wall and the load coming down from the roof.
• Roof repair and strengthening. Trusses and purlins may need temporary support while members are repaired, replaced or strengthened, without overloading walls that are already carrying spread from the roof.
• Wall and gable stability. Walls that lose restraint during the works, or that already lean, may need temporary restraint until the permanent structure is complete.
• New foundations and underpinning. Excavations close to shallow historic footings need support designed to protect the existing structure as well as the people working in them.
• Scaffolding and temporary roofs. Access scaffolds and weather protection put tie loads and wind loads into old fabric. Ties need to be positioned and tested with the condition of the masonry in mind.

Design check categories across the three structures

Because the alterations vary in scale and complexity, the temporary works do not sit in a single BS 5975 category. Standard proprietary propping used within its published limits may fall in the lower categories. Needling through rubble filled walls, temporary support to historic roof structures and restraint to unstable walls will typically need an independent check at Category 2 or above, depending on complexity and the consequence of failure.

Assigning the right category at briefing stage protects both the buildings and the programme. A check at the wrong level either misses risk or adds delay that could have been avoided.

Coordinating with the wider scheme

The barns sit within a larger infrastructure project, so their temporary works cannot be managed in isolation. Plant movements, adjacent excavations and vibration from nearby activity can all affect historic structures. Where that risk exists, monitoring requirements are set as part of the temporary works design and linked to clear trigger levels and actions.

Coordination also runs the other way. The permanent works designer, any heritage advisers and the site team all need to understand how temporary works affect sequence, access and the fabric being retained. Bringing those parties together early avoids redesign later.

Protecting what is being kept

The purpose of temporary works on a conversion is to allow change to a building while protecting the parts being retained. On structures of this age that fabric cannot be replaced like for like. A careful, well coordinated temporary works process is how the new use is delivered without losing what makes these buildings worth converting.

Matthews & Roberts provides temporary works coordination and consultancy and temporary works design for contractors working on complex and historic structures across the UK.