New construction Zuidblok | Stadionplein, Amsterdam

Mortar behaviour

Glazed bricks are relatively hard, so sawing bricks on site was not an option. The work plan therefore included the criteria that, where necessary, the glazed bricks would need to be sawn. There were, however, also other aspects involved in executing the project that correspond with the amount of brickwork during the process. Buckens: ‘We analysed the behaviour of the mortar extensively for colour and processing aspects. Particularly where it is important to achieve a smooth surface – we refer to it as aesthetics.’ Important lessons were learned by building a number of trial walls. ‘Glazed bricks do not absorb very much water during processing. This means that, depending on weather conditions, you can only lay bricks all at once.  This information was also included in the work plan.

Just in time

Trial walls were also used to test how to handle the mortar and pointing. The dilatations were taken care of with sanded kit mortar (see the interview with Alexander Pols). ‘During the project, we used a pointmaster to lay the glazed stones’, explains Buckens. ‘After rolling the mortar, the glazed bricks needed to be cleaned quickly: a meticulous job that has to be performed just in time. In practice, it takes the bricklayer extra time.’

Add to that the Dutch weather. During bricklaying, heavy concrete belts had to be placed between the brickwork using a mounting crane, which meant that it was not possible to fit a roof above the scaffolding. Timing was also tight in this respect. Buckens: ‘The weather was kind to us: it stayed fairly dry. And because we were well prepared, we experienced virtually no hold-ups during the bricklaying process.’