Global Roofing Solutions’ Klip-Lok 700 and Brownbuilt concealed-fix profiles were specified for the Multichoice City roof.

The new Multichoice head office building in Randburg has been completed and with its state-of-the-art design and imposing roof, this four-storey building is hard to miss on the corner of Republic and Bram Fisher Roads.

Six years ago, GLH Architects started to design this contemporary new headquarters for Multichoice – a building that would be completely different from the old campus and which could accommodate all their employees in one space.

For the roof, Global Roofing Solutions’ Klip-Lok 700 and Brownbuilt concealed-fix profiles were specified, and applied in an inventive way to create a big canopy on the western side of the building and a cladded look for the underslung portion.

“The roof design is quite unique,” comments Lyle Jeffery, Global Roofing Solutions’ projects and specifications team national manager. “While installing the Klip-Lok 700 for the main portion of the roof was pretty straightforward, we got involved in planning the details for the Brownbuilt underslung with regards to how the sheeting would be fixed and flashed. This was quite a difficult flashing since it was curved, so we worked with the roofing erector to work out how to best tie in the roof,” he explains.

Brownbuilt installed as soffit
“The benefit of the Brownbuilt roofing profile, and the reason for it being specified for this project, is that it is able to serve a dual purpose in the sense that it can be used for roofing as well as a ceiling or soffit sheet. And for Multichoice City, a specific detail was required for the underslung,” adds Jeffery.

The Brownbuilt profile was installed with the rib facing up and a special H9 clip was used to install the sheeting under the purlin, rather than the traditional way of over purlin. This H9 clip allows Brownbuilt to hang from the purlin with the underside of the profile being visible.

Wishbone Sanyika, associate and architectural technologist at GLH Architects, says the Brownbuilt profile complements the horizontal lines that are prevalent on the building and provided the look and effect that they wanted to achieve.

“Installing the Brownbuilt sheets the way it has been done beneath the roof, one can hardly see that it is a roof sheet. It looks like a cladding material, so it works very well. Other types of cladding would also have cost a lot more, for the same effect,” he says.

Western overhang
With the building orientated west, due to the site location, a big consideration of the design was to control light glare and heat from the sun hitting the impressive bean-like glass facade on the front of the building.

“The steel roof creates a big overhang, kind of like a cap, to provide shade over the western facade and reduce glare into the building in order to minimise the required use of artificial cooling,” explains Sanyika.

“The canopy cantilevers for about 8m, but in total the roof sheeting spans about 12m to 13m in order to create the overhang. Therefore a roofing sheet that could span a great length was required. Other than providing the required profile, Klip-Lok 700 enables great spans and it seems like it was the right product for the building,” Sanyika states.

Green rating
The building has achieved a five-star Green Star SA Design rating and is currently being considered for an As Built certification by the Green Building Council of South Africa (GBCSA).

Multichoice City is also one of four Global Roofing Solutions projects entered into the Steel Awards this year.

Global Roofing Solutions
Tel: 011 898 2900
Email: info@globalroofs.co.za
Website: www.globalroofs.co.za

In brief:
Project: Multichoice City
Location: Randburg, Johannesburg
Completed: 2015
Rating: Five-star Green Star SA Office Design V1
Roof profiles: Klip-Lok 700 steel roof
                         Brownbuilt underslung