Duratec recently restored this State heritage-listed facade, reclaiming a piece of the city’s history and ensuring its existence for future generations.
Brisbane historians will be familiar with Finney Isles & Co, a draper’s store that was established in Fortitude Valley in 1864. The business eventually expanded into a department store and in 1909, new premises were constructed in the CBD’s Queen Street. The building was named ‘The Big Block’.
Designed by CW Chambers and constructed by J Mason, the building comprises three floors on
Adelaide Street and five floors on Queen Street. It represents one of the first times reinforced concrete
was used for structural purposes in Queensland. The building’s Queen Street facade contains five vertical bays of windows above the ground level. The bays are divided by slender columns and mouldings extending into delicate floral decorations at their top.
The cornice is adorned with intricate mouldings and two rows of rosettes on the soffit and face. The
words, ‘The Big Block’ and ‘Finney Isles & Co. Limited’, feature on the parapet in raised uppercase lettering.
The Big Block was listed on the Queensland Heritage Register in 1992 for its historical, cultural and
aesthetic significance. It demonstrates the principal characteristics of a larger scale, early-20th century
department store and exhibits important aesthetic characteristics valued by the community.
Setting the scene
Situated in Brisbane’s Queen Street Mall, QueensPlaza is home to high-end retail outlets and restaurants, and has been described as a “centre of stylish elegance”. Its location experiences a lot of foot traffic so the art-deco Queen Street facade is highly visible.
While a large renovation of QueensPlaza, including remediation to its heritage facades, had taken place
in 2005, the full extent of the repairs was unknown. By 2021, concrete deterioration to the Queen Street
facade was visible, so the building’s owner, Vicinity Centres, engaged Duratec to undertake a thorough
investigation to determine the extent of the damage.
Assessing the damage
Visual inspection and delamination survey
Duratec’s mission was to perform a visual inspection and delamination survey across the facades using
rope access. The company’s in-house engineers performed the survey at night, due to city council requirements, by lightly tapping or rubbing a hammer on the rendered surfaces and listening for ‘hollow-sounding’ areas. The defect locations were then marked on drawings and recorded on an associated defect register.
The verdict
Typical findings of the investigation included the following:
- Delamination and cracking across ornate window tiles
- Deterioration and spalling to previous repairs
- Hairline cracking to uncoated areas of facade
- Localised areas of larger cracking and delamination
- Widespread coating failure causing moisture ingress into the building
- Longitudinal crack near bottom of lettering, as well as associated localised delamination
- Significant amount of delamination around larger openings for service windows
Can we fix it? Yes, we can
Following the visual investigation and delamination survey, Duratec provided a list of recommendations
regarding the restoration of the facade. This advice centred around the following tasks:
- Engage heritage consultants and authorities to:
- Advise on building elements of significance
- Provide guidance for repair methodologies and testing, including paint specification and compatibility
- Conduct representative testing of facade, including hazardous material testing, to determine construction details and material composition
- Perform repairs to areas of cracking and delamination, keeping in mind that further investigation may be necessary in order to determine full extent of damage
- Prepare surfaces, including window frames, and re-coat facade using a suitable crack-bridging coating system
While these were Duratec’s initial recommendations, the restoration journey was only just beginning and as with all worthwhile projects, there promised to be plenty of twists and turns along the way.
First things first
Collaborating with those in the heritage know
After receiving Duratec’s inspection report and sighting the meticulously documented defects, Vicinity Centres engaged Duratec to undertake the recommended works and restore the Queen Street facade to its former glory.
In line with recommendations, the first step was to engage heritage specialists to provide expert advice that would ensure the repairs remained true to the structure’s original architectural details. Extensive collaboration with the Queensland Heritage Council, heritage architects and the Brisbane City Council allowed Duratec to secure the requisite permits and ensure adherence to heritage standards.
The scaffold set-up
QueensPlaza’s location in the middle of a busy shopping precinct proved a challenge in terms of access. The works required an innovative scaffold that would ensure safety and cause minimal disruption to both the tenants and the public. While Benchmark Scaffolding was engaged to fabricate the scaffold, Duratec was heavily involved with the design. This included specialist engineering to retain the glass awning above the luxury boutique stores at street level.
It was crucial that these stores remained accessible at all times so installation of the scaffold took place largely at night. Black hoarding featuring the stores’ logos was also installed to reinforce the ‘business as usual’ message.
Concrete spalling repairs
Duratec’s visual investigation and delamination survey of the Queen Street facade had turned up more than 150 defects. Once the scaffold had been installed, Duratec mobilised on site and got to work performing conventional repairs to the concrete spalling. To facilitate these repairs, Duratec
removed lead paint as it was discovered.
The concrete repair process involved cutting around the defects, jackhammering out the damaged concrete and patching it up with a repair mortar, thereby preserving the facade’s structural integrity.
And then there was the crown cornice
In short, the state of the crown cornice was a surprise to everyone. Once the team reached the decorative architectural feature towards the top of the facade, the extent of the deterioration to the intricately designed castings became abundantly clear. The crew stripped the paint and discovered that water had been seeping in through the top of the cornice, causing cracks and holes to appear around the rosette details below. In fact, the condition of the mouldings was so poor, it became obvious that all 72 (36 on each of the two rows) would have to be replaced entirely.
Reconstructing the past
The team proceeded to consult with the State Heritage Council and gain approval to reconstruct the mouldings look exactly like the originals from 1909. To do this, Duratec engaged a specialist subcontractor to take a silicon moulding of the best example of the decorative tiles, fix the cracks and
imperfections, and reproduce new castings like-for-like.
Chasing out the cracks
Once the tiles were removed, the team was left with a bare substrate displaying significant cracking. As a remedy, crew members ‘chased out’ the cracks by first expanding them with a grinder so they were slightly wider at the top. The cracks were then sealed with high-performance sealant to ensure the element was waterproofed.
Larger structural cracks were ‘stitched’ by cutting out slots perpendicular to the crack and installing steel reinforcement bars using a chemical anchor. After all the cracks were repaired, a waterproof membrane was installed and that was one of the most crucial preventative measures undertaken by the team – a robust coating to stop the ingress of water, which had been a principal cause of the cornice’s delamination over the years.
Removing rust and building strength
So that’s what was involved in remediating the top of the cornice. Then there was the soffit which had deteriorated so much, it exposed the structural steel beam within. This is where Duratec’s specialist applicators came in.
Traditional blast and paint equipment was not an option for myriad reasons, e.g. restricted space, height, noise, to name a few, so the crew used bristle blasters – hand-held power tools – to remove the corrosion and bring the beam back to clean steel. A protective coating was then applied, before the installation of additional steel reinforcement and the rendering of the soffit with a high-build repair mortar. This made the cornice square and plumb and ready for the installation of the decorative features.
Reinstalling the jewels in the crown
It was now time to install the refabricated motifs. Coming up with a methodology for affixing these specially engineered tiles to 130-year-old concrete took some time. Great thought was put into the best way to install them, a way that would ensure safety and longevity.
Intensive liaison with the consulting structural engineer, as well as a fair amount of testing, was undertaken to ensure the best possible method was implemented. After several different trials, the structural engineer determined the most suitable course of action and Duratec got to work affixing the
tiles to the crown cornice in the recommended manner.
The crew inserted a 12-millimetre threaded rod, fastened with a hex head nut and washer, through the middle of each rosette, well and truly adhering each tile to the crown cornice. On top of that, the team installed six-millimetre lengths of threaded rod around each casting as extra protection to bind the new castings to the concrete behind them. Those decorative tiles are not coming down in a hurry.
Nothing like a fresh coat of paint
The new mouldings were then painted over in a ‘manila’ colour that matched the original facade like-for-like. To concoct this colour, the heritage consultant engaged by Duratec took a paint sample and then provided a colour code for that particular hue. This allowed Duratec to ensure the entire facade remained true to its original aesthetic.
Before the facade’s refurbishment, the raised uppercase lettering on the parapet had been painted over in the same ‘manila’ colour as the rest of the facade. The heritage consultants suggested that Duratec repaint the lettering in its original blue tint, thereby making it ‘pop’ and reinstating the aesthetic of 100 years prior.
A protective coating was then applied to the entire facade, maximising its longevity, and the window frames were painted a heritage green, enhancing the aesthetics.
The same… but different
The thing about remediating buildings, especially those of historical value, is that it’s often hard to tell the difference between the original structure and the refurbished version. Obviously, the QueensPlaza facade now looks fresh and new, but none of the structural features have changed and it integrates seamlessly with its surrounds.
The importance of building relationships
The refurbishment of the QueensPlaza facade was not a straightforward project. The century-old structure held secrets that could not begin to be investigated in any detail until, firstly, Duratec’s engineers abseiled down the building and recorded defects that were visible to the naked eye. Even then, it wasn’t until the custom-designed and fabricated scaffold was in place that the crew could start breaking out the concrete to see what was really going on. And to what extent.
Thankfully, Duratec’s client, Vicinity Centres, was fantastic to work with – always available for consultation, only too happy to collaborate and consistently open to advice and recommendations. Though the project took longer than originally hoped, frequent consultation with heritage experts and clear communication regarding innovative remediation techniques have meant that this structure is going to stand the test of time.
And that’s a credit to Vicinity Centres who, in the long run, will save time and money as the renewed facade holds its own well into the future.
Interesting tidbit
Upon removing the original decorative tiles from the crown cornice, the team knew they were too historically significant to just dispose of in landfill. In the interests of heritage preservation, the crew salvaged those that were most intact and have stored them on site in a designated ‘heritage room’.
The thinking is that if anyone needs to take a look at them in the future, they’re there, waiting to be inspected. And who knows, perhaps an archaeologist will stumble across them in several hundred years and proceed to write a dissertation on 20th century department store architecture. Stranger things
have happened!
Service provisions
Upon completion of the heritage restoration, Duratec, in partnership with various specialists, consultants and subcontractors, had delivered the following:
- Technical inspection, including defect mapping
- Scaffold design and installation
- Lead paint removal
- Concrete remediation
- Crack repair
- Structural strengthening
- Waterproofing
- Painting
- Protective coating
