Gosford Quarries’ sandstone heritage restoration in Sydney, Melbourne, Brisbane

Around our nation, and especially in our major cities, Sydney, Melbourne and Brisbane among them, the vision of our architecture is filled with sandstone walls, cladding, capping, pyramid capping, profiled sandstone, decorative pieces, rosettes, quoins... the list goes on.

The contrast of heritage and contemporary buildings in the Sydney visual scape is now something we admire and celebrate. We must pay homage here to Sydney City Council. Governor Macquarie Tower was the first contemporary use of sandstone (a sandstone veneer instead of a pre-cast concrete panel). In reaction to it, the Council realised just how much sandstone was a part of the identity of Sydney.

“Sandstone is warm, inviting, and empathetic; everyone seems to empathise with sandstone and embrace it and love and take pleasure from it,” says Gary Hargreaves, Gosford Quarries.

Sandstone is woven into the history of these iconic buildings. Woven into their fabric is the heart, love and industry of the masons and experts of Gosford Quarries, reaching as far back as the early 1920s in sandstone projects and to contemporary Australia today.

“Gosford Quarries has become the leading heritage sandstone restoration company, premier supplier of bespoke heritage pieces, and a sandstone company that has become an expert adviser on sandstone restoration projects with a remarkable 100-year history of knowledge and experience gained over our century of operation (1922-2022),” says Hargreaves.

Gosford Quarries' name has become synonymous with trust and the highest calibre of quality for not only sandstone supply for sandstone heritage restoration, but capability, advice, manufacture and sometimes, installation. Mostly, though, there are installation companies who handle the actual heritage restoration installs of the stone.

In the 1980s, the Museum of Sydney was supplied and fitted with a new sandstone cladding by Gosford Quarries.

From St Mary’s Cathedral to the GPO, the Sydney Town Hall, the QVB in Sydney, the War Memorial of Canberra to the Parliament of Victoria, cathedrals in Tasmania and Marble Hill Governors House restorations in Adelaide, Gosford Quarries has supplied heritage sandstone to some of the most iconic buildings in Australia’s history.

“Gosford Quarries has a singular capability to quarry onsite. The latest sandstone technologies and state-of-the-art 3D machinery allow incredibly precise matching of the shape and finishes of sandstone pieces required in heritage restoration. Heritage pieces are scanned from originals or produced from advanced CNC programs (such as CAD and Rhino), cut at our factories, and often hand-finished in bespoke heritage sandstone finishes,” explains Hargreaves.

The vast experience with historic buildings and extensive I.P. held by our senior expert staff and architectural draftsmen have made Gosford Quarries a top of mind partner in countless historic building restorations over the last 100 years.

“Our highly skilled banker masons at Gosford Quarries are heavily involved in heritage sandstone restorations. Some heritage sandstone finishes require human ingenuity and skill, which only a highly skilled mason can provide. It is often assumed historical sandstone finishes cannot be accurately reproduced in the present day. In fact, the contemporary rendering of a heritage finish is basically indistinguishable from the older sandstone blocks they have replaced,” notes Hargreaves.

Popular and historical sandstone finishes are sparrow peck, convict picked, bush-hammered, boasted and chiselled.

In fact, the famous ‘Yellow-Block’ sandstone of Sydney has been quarried by Gosford Quarries at various sites in the Sydney CBD (particularly 200 George St) for its unique character and is a perfect match to the historic buildings in need of repair and restoration.

We also have stockpiled certain sandstone reserves of rarer sandstone colour ranges specifically for sandstone restoration. Regarding heritage restoration, Gosford Quarries has no equivalent in sourcing the actual stone suitable for this task.

Many heritage restorations result from physical water damage to the sandstone materials, chipping, or some kind of physical damage to the stone. Due to the uniqueness of the rarer sources of sandstone that have been used in heritage buildings, Gosford Quarries can help to specify the best match of sandstone material for each unique sandstone restoration, further ensuring the replacement product will be the closest, almost indistinguishable match to the sisters and brothers it will live alongside.

Gosford Quarries is committed to dedicating our resources to ensure Sydney’s landmark buildings and the beloved sandstone of their foundations and their skin remain preserved, renewed, and restored to continue as long-lasting testaments to our nation's industry architecture and vision.

“Quarry tours can be booked for up to 15 people at a time to see and experience our sandstone technologies and masonry live, on-site, at our Gosford Quarries Factories. This can help assure any prospective heritage project architect of our singular capabilities within the whole ecosystem of sandstone restoration,” says Hargreaves.

After completing our quarry and factory tours, architects are usually in awe at the execution of detail we can achieve!

Below are some of the most important buildings in Sydney that have involved Gosford Quarries in site visits, consultation, quarrying, scanning, profiling, transport and, at times, installation.

Sydney Town Hall Sandstone Restoration Project

Gosford Quarries has been deeply involved with Sydney Town Hall’s various stages of sandstone heritage restoration for decades.

Sydney Town Hall - Custom Profiled Heritage Restoration Sandstone

Restorations to the main pediments commenced due to the ‘Royal Visit’ of 1991; it was decided that the city had to renew the old building that was Town Hall, a considerable architectural landmark of the city.

Some of the most significant works have been our work on the front entry steps, the ramp and twist balustrades, and all the balustrades at the front of the building. Gosford Quarries also restored the marble lining step treads.

We have worked on the building's Druitt Street and Town Hall Square sides.

“Gosford Quarries predominantly supply sandstone to heritage restorers in contemporary times. These heritage restoration businesses come to us for complex stones required for manufacture for restoration. Wherever the sandstone material is sourced, it goes to our Gosford Quarries factory, where we profile and cut the stone. Sometimes, it also has heritage finishes applied by hand and tool,” says Hargreaves.

Most Sydney City restorers use Yellow-Block sandstone when they can get it; it is in limited supply these days. We hold a reserve supply for these kinds of heritage projects.

We have a fantastic relationship with our sub-contractors, who come to us for advice in the tender for heritage restoration projects. Also, if successful in the tender, they come back to us with information to quote and, importantly, for aftercare.

In terms of sandstone heritage restoration, we give advice on how to colour or shape the stone further if needed.

GPO (General Post Office) Sydney Restoration Project

Sydney's GPO is regarded as Australia’s most significant sandstone architectural building. Did you know this project was so significant that Martin Place was widened to create the space for the GPO?

The building was controversial to a degree with its choice of bells and the fact that they commissioned carvings from the Italian immigrant sculptor Tommaso Sani.

GPO Sydney

GPO Sydney – Original Yellow-Block Sandstone restored with Gosford Quarries’ Debden sandstone colour range

The original building was constructed in two stages beginning in 1866 and was designed under the guidance of colonial architect James Barnet. (Source: Wikipedia)

Gosford Quarries serendipitously found a self-colouring sandstone (the best for the purpose of the GPO restoration) to fit into this facade during restoration. The sandstone material was a naturally oxidised sandstone called ‘Debden Sandstone’. It oxidises into the perfect colour for the restoration of the GPO. It was truly a remarkable find.

The Debden quarry has long been finished, and we no longer have this material available.

Six thousand cubic metres (gross metres), representing 10 thousand tonnes of sandstone were installed in 4 years, from 1987 through to 1991.

In the 1970s, Gosford Quarries brought out 3 talented stone masons from England. These exquisite stonemasons were faster than any stone made by a machine, stayed with us all these years and created all the carvings for the GPO!

GPO Sydney

GPO Sydney

During the four-year restoration, Gosford Quarries went around the facade, replacing cornice rosettes suffering water damage. These had become a safety hazard as a few plummeted from their perches above.

Predominantly our sandstone heritage work on the GPO involved replacing the level 3 cornices.

Each rosette was salvaged, sent to Gosford Quarries, faithfully restored, and carved onto the new stone by our stonemasons. It was an enormous endeavour. In the present day, if you were not told the cornices had been replaced visually, you would never know; such is the faithful match of our restoration to the original stone.

Other restoration works for the GPO included replacing the parapet stones and the pediments on the parapets. Also, we worked on the stones in the clock tower. These replacements are a bit more obviously restored Debden stones that we put in. We had a crane in Martin Place, and all the heritage restored sandstone pieces were lifted onto the scaffold and then the clock tower directly.

The pieces were 2.5-3 metres long, 1.2 metres wide, 0.5 metres thick, with 0.5 rosette carvings underneath. These were handmade heritage sandstone pieces, and very expensive – each piece was approximately worth around $15k!

During this incredible process of lifting such heavy pieces and the risk of damage, no single rejection of chipping or other problems with the stone was reported or demanded. Similar to the sandstone we discovered, this was another incredible outcome for the GPO heritage restoration project.

The scope was not only grand in the product but also in manpower: 30-40 quarrymen and 10 stonemasons were involved along with some ‘modern machinery’ of that era, not nearly the highly sophisticated standard machinery we have today. They were, though, fairly sophisticated saws. The carvings were all done by hand in the traditional banker mason form.

GPO Sydney

GPO Sydney - Original Yellow-Block Sandstone restored with Gosford Quarries Debden sandstone colour range

The original stones were cleaned before World War II. When sandstone is cleaned, you can often remove surface oxidisation; the result is a ‘ghosting’ looking stone instead of the proper Yellow-Block colourations famous in the region.

Sandstone is part of the Sydney story.

It is an Australian fact that the ground we walk on from Pyrmont to Eastern Suburbs is the same self-colouring oxidising sandstone, the ‘Yellow-Block’. It does not exist further than Pyrmont.

There have been famous quarries in Waverley and Bondi that have contributed to the sandstone in the city. However, the extensive building works of the 1930s depleted all the quarries.

“The Wondabyne Sandstone Colour Range became the pre-eminent stone used in the city for claddings and new facade works that were forthcoming in later years,” says Hargreaves.

St Mary’s Cathedral Sandstone Restoration Project

In 1882, though unfinished, St Mary's Cathedral was opened to the public and dedicated.

Historically, the sandstone of St Mary’s Cathedral was quarried at Wondabyne and moved via rail to Pyrmont, then machined and transported by trucks. Hence, the sandstone colour range of St Mary’s Cathedral is called ‘Wondabyne’.

It was in 2000 that the southern spires were installed to complete William Wardell’s design (the original architect of the Cathedral).

St Mary’s Cathedral

St Mary’s Cathedral - Spire Restoration Project - Wondabyne Sandstone Colour Range

“The sandstone required for St Mary’s Cathedral heritage restoration and renewal was quarried from Wondabyne and cut to sizes required on-site and installed by Gosford Quarries as an exclusive installation project circa 2000,” says Hargreaves.

St Mary’s Cathedral

St Mary’s Cathedral - Installation of replacement sandstone spire panels by Gosford Quarries

“Archbishop John Polding commissioned architect William Wardell to design a new St Mary’s following the devastating fire in 1865 that razed the original Cathedral. According to Archbishop Polding to Wardell in a letter dated 10 October 1865: ‘Any plan, any style, anything that is beautiful and grand. I leave all to you and your own inspiration’.”

“Despite the building’s European origins, Wardell used Australian native flora throughout as a decorative element to ground the Cathedral in its local setting,” explains Hargreaves. (Source: St Mary’s Cathedral)

Governor Macquarie Tower Sandstone Restoration Project

The Governor Macquarie Tower featured a 75mm thick sandstone cladding. Gosford Quarries supplied 8000 square metres of sandstone for the internals and externals of this project.

One of the most underestimated buildings in Sydney, it was a bold decision for architects in 1991 to use sandstone as external cladding. It signalled the end of the era of precast panels.

Governor Macquarie Tower

Governor Macquarie Tower - Internal photo of Sandstone Honed Cladding, Pies Creek Cream Sandstone Colour Range

The architects chose sandstone in ‘Sandstone Sydney’, setting a precedent for the Sydney City Council to nominate and encourage sandstone across the periphery of the buildings.

Heritage sandstone specification

Sydney has light honey-coloured sandstone suitable for the heritage stone fabric we live within our city.

We are often top-of-mind for architects and a go-to for advice and material matching for sandstone restoration projects. Modern projects are no different if the architect is envisioning the use of cladding or a base course of sandstone as decorative elements in their architectural design.

Sandstone Heritage Finish

Bespoke Tooled Sandstone Heritage Finish - Yellow-Block Sandstone Colour Range Sydney CBD

“Gosford Quarries works closely with architects to understand what they are trying to achieve and gives guidance and support to specify the sandstone material that will suit the architectural purpose envisioned for each project,” says Hargreaves.

It can take up to 5-6 years from documentation to tender, to win, and to build before the final sandstone project is handed over to installers. We are with you every step of the way.

If we are going to restore our Australian heritage buildings, when considering the time, effort and expense it takes to put one stone in place with any significant building, it has to be a higher quality sandstone that we have in supply to rise to the honour and respect such building’s command.

On a specification, if Gosford Quarries is mentioned, it is because it is a precedent that has been set by the 100 years of trusted experience, technology and skill and the extraction of premium sandstone.

It is crucial to receive good advice earlier in a project's life and to ensure specification is done right the first time. The use of sandstone is not as dense as marbles or granites and has to be used in particular ways, not under or over-specified architecturally. It takes particular industry know how from decades of experience to be able to provide this kind of expert advice.

“In the heritage sandstone material market, Australia has no equivalent to Gosford Quarries as a heritage sandstone supplier,” concluded Hargreaves.

As a custodian and conservation expert, focussed and committed to the preservation and longevity of our beloved landmark sandstone buildings, Gosford Quarries is looking forward to the next 100 years of heritage sandstone supply, restoration and renewal in Australia.

Top image: Sydney Town Hall - Piles Creek Cream Sandstone Colour Range

Architecture & Design Team

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Gosford Quarries

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