Sydney landmark unveils glamourous makeover
One of Sydney's most iconic buildings, Shell House has received a glamourous and sophisticated restoration. Dulux Protective Coatings was there from the beginning to assist with the ambitious three year project, completed in late 2021.
Constructed in the 1930s, Shell House has a rich heritage as Sydney's only surviving inter war commercial palazzo-style building. The restoration project demanded a carefully engineered approach, led by local construction company Multiplex.
Clad with glazed terracotta faience blocks, Shell House’s façade is also one of the tallest retained heritage façades in the world. Importantly, the interior of the building was returned from a hotel to its original purpose as office space. To deliver on the architect's contemporary vision, more than 2500 tonnes of steel was required for the fit out, supplied and erected by Belmore Engineering.
Dulux Protective Coatings was selected to supply protective coatings for the extensive structural steel works, working collaboratively with Promat to specify systems that met both aesthetic and regulatory needs.
A four-coat system is specified
Technical Sales Representative Dan Jones says the Sydney landmark's steel infrastructure required a specialised system that offered protection against both fire and corrosion.
"We collaborated with Promat to provide a specification that would meet the complex needs of this architecturally brave project," Dan says. "This included the application of intumescent paints that are designed to protect structural steel from the effects of fire."
The four separate coats of Dulux Protective Coatings products were applied in two different locations.
- Coat 1: Duremax GPE ZP
- Coat 2: Cafco WB3
- Coat 3: Duration T80
- Coat 4: Duration T80
"The first priming coat of Duremax GPE ZP was applied at Belmore Engineering's steel fabrication in Tamworth," Dan explains. "The steel was then transported to Sydney to be erected. Great care was taken by the fabricator's rigging team to limit damage to the primed product during the move. The specialised team at McNaught Group were then brought in to apply the intumescent coatings on site."
Duremax GPE ZP is an epoxy primer that boasts both anti-corrosion and strong adhesion qualities – perfect for Shell House's steel structures. It was followed by the application onsite of Promat Cafco WB3.
The important role of intumescent coatings
The building Code of Australia (BCA) requires certain structural elements to be protected against fire. Intumescent coatings, when correctly specified, can provide up to 120 minutes fire protection on structural steel (testing according to AS1530 Part 4).
"Cafco WB3 is a water based intumescent coating that works by expanding when heated to form an insulating char around the substrate," explains Dan. "In ambient conditions the thin coating allows for the steel structures to maintain their usual form. This means the architectural value of the steel beams can be retained and openly displayed to create the desired visual effect, rather than being boxed in with a board or covered with fire spray."
Cafco WB3 was also specified because of its low odour and low VOC benefits.
Finally, two top coats of Duration T80 was used. Selected as the finishing product because it is a water borne, fluorinated polymer finish, Duration T80 also demonstrates excellent gloss and colour retention and is designed to endure extended service periods.
"We delivered this via a system with a very low VOC content to address environmental conditions on site, where workers could not be exposed to strong paint odour,” says Dan.
The transformation of Shell House was completed in late 2021 and has reignited CBD corporate and dining culture, with the inclusion of the luxe Sky Bar atop the reimagined office space. New residents have settled in and are enjoying their contemporary interior, knowing the structure will continue to meet the highest standards of fire protection for many years to come.
Bonus fact: In a modern feat of engineering, the famous Shell House 400 tonne clocktower was suspended mid-air over the building for the three-year duration using steel trusses while the interior of the building was excavated and rebuilt!