The large-format tiles were installed from ground level in a portrait design making up the first segment of the triple-volume installation.
The 10 500 m2 turnkey office development is located just off William Nicol Drive, within the highly-successful Bryanston office node.
The ‘retro concrete’ aesthetic effect of the major wall featured in the two triple-volume atria entrances of Blocks A and B, was the vision of architect Boogertman + Partners. Vitrified porcelain tiles, beige and light-grey in colour and in different sizes, varying from a massive 3 m x 1 m to 300 mm x 600 mm, were specified to achieve this effect.
TAL Technical Supervisor Sharon Margon explains that, as these were such large-format tiles, back-buttering of the individual tiles was required to ensure a full contact between the substrate, adhesive and tile. The installation process proved quite tricky due to the large size of the tiles, with the tiling contractor Ohlhorst Africa, having to manoeuvre around and onto the scaffolding.
A tile could only be back-buttered once positioned on the scaffolding, or it would have resulted in ‘skinning’ of the adhesive on the ascent, and an impaired adhesive bond. This meant that the workflow between trowelling onto the wall and back-buttering of the tiles had to be absolutely perfect.
Four to five workers manoeuvred a single tile into place, with one worker trowelling the adhesive onto the wall and another back-buttering the tile, after which the tile was tapped gently into position using a rubber mallet.
Adhesive had to be trowelled in a 3m² area in a single operation. These large-format tiles were installed from ground level in a portrait design in order to make up the first segment of the triple-volume installation. Tiling above this point was carried out using various-sized tiles to achieve the required aesthetic effect.
Such large-format tiles, required back-buttering of the individual tiles with TAL Goldstar 6 and TAL Goldstar 12 was applied on the wall, to form a single adhesive system.
Margon highlights how the different setting times of TAL Goldstar 6 and TAL Goldstar 12 were used to facilitate the tile installation. Woodfloated plaster can be a relatively porous substrate, which may absorb the mixing water from the adhesive quite quickly.
TAL Goldstar 12 was therefore used for application onto the walls, as its longer open and setting times allowed sufficient time for the large-format tiles to be manoeuvred onto the scaffolding and back-buttered, and also to account for any subtle adjustments once the tile had been placed. The backs of the tiles were back-buttered with TAL Goldstar 6.
In this instance, using two different adhesives was not an issue, Margon points out. “They are both based on high-strength rapid- and quick-setting technology, and as such are fully compatible and, once combined, form a single adhesive system.”
TAL Bond, a modified latex-based additive, was also used as a water placement in the adhesive mix for enhanced bond strength and flexibility, and to allow for any thermal movements arising from sunlight through the large windows.
