Typhoo Tea Building, Birmingham

More than 12,000 square metres of a former tea factory is being transformed into a state-of-the-art broadcasting facility for the BBC – and Proctor Group’s Wraptite® membrane is playing a part in bringing “a 100-year-old industrial building back to life for the next 100 years.”

The Typhoo Tea Building occupies a full city block in Digbeth, Birmingham, near to the city’s HS2 terminal. The factory has gone unused for four decades, but is being turned into a net-zero-carbon workplace. The scheme is a first step in a wider plan to transform the area over the next ten years. The tea factory’s design, by architects Howells, was developed to meet BREEAM Outstanding 2023.

Respecting tradition while delivering modern performance

As an existing building, the former Typhoo factory presents a host of challenges that would not be encountered on a new-build project. Arguably one of the most important of those challenges to get right was finding a solution that could deliver a good standard of airtightness while protecting the traditional brickwork superstructure.

Wraptite provides a consistent airtight seal that contributes to meeting a project’s airtightness target. Alongside that, it is also highly vapour permeable and allows the passage of moisture vapour out of the structure.

This is essential for avoiding any increase in condensation risk in buildings of all types. It is also critical in existing buildings where the moisture transport properties of traditional masonry have to be preserved so the brickwork can “breathe” and properly dry out when wet. A vapour-closed construction prevents masonry from drying to the inside and increases the risk of mould and eventual decay.

A typical new-build project sees Wraptite installed to the external face of a sheathing board that is fixed to the structural frame. Maintaining the outward appearance of the old tea factory and its existing brickwork meant applying Wraptite to the internal face of the masonry.

Applying Wraptite membrane to existing brickwork

The job of installing Wraptite in this relatively uncommon way fell to specialist contractors CG Reynolds, whose work package included the steel frame system, partitions, and ceilings as part of the Category A fit-out.

For their first time installing the product, CG Reynolds could not have picked a more challenging project. An existing substrate does not generally offer the consistency and predictability of a new-build project. As such, all of the brickwork had to be repaired, then brushed down to ensure there were no sharp edges that could damage the membrane.

As a self-adhered membrane, a key feature of Wraptite is that it can be installed without the substrate needing to be primed. Here again, the existing brickwork substrate presented a challenge. Its dusty surface risked impacting on adherence.

Trials on site suggested that Wraptite was adhering to the brickwork. On such a large building and prestigious project, however, CG Reynolds were not prepared to take any risks. Adopting a belt-and-braces approach, they chose to prime the brickwork anyway for complete certainty.

With that decision made, installation progressed quickly as the installation team got to grips with the product and the application. “It’s gone alright, to be fair,” was the modest verdict of Steve Upton, Operations Director at CG Reynolds. ”

A joined-up approach to project support

Proctors supported CG Reynolds throughout the installation, visiting site multiple times to assist with queries and provide progress reports.

“Proctor Group came to site a lot,” said Steve Upton. “They were proactive and gave a lot of support.”

Broader support began in the earliest stages of the project and encompassed all aspects of the project team, starting with the architects. The Proctor Group technical team was involved with initial discussions about material choices.

“We discussed the benefits of various options, linked to the requirements of the project,” said Pamela Howat, Proctor Group’s Senior Technical Advisor. Detailing queries that the technical team helped to answer included how to marry the work on the existing walls with new-build elements, and sealing around the window openings and at the junction with the profiled metal sheet roof.

Proctors was also involved in the discussions with Howells. Alongside that, and his work with CG Reynolds, he also supported the local distributor. “They are just around the corner from the site. Helping to make sure product was available when needed was another way of contributing to the smooth progress of the installation,” Proctors explained.

For any project – but especially one of the size and complexity of the Typhoo Tea Building – such a joined-up approach to technical support should be the norm rather than the exception. Helping to translate design decisions into as-built reality makes it more likely that a transformative retrofit like this delivers on its promises, and shows that there is plenty of potential in our disused building stock.