Products up to 14kg (bricks and the vast majority of blocks) can be laid manually. Products weighing more than 14kg are laid mechanically in accordance with Working Conditions legislation (“Arbowetgeving”). Mechanical aids have been specially designed for this purpose, and they guarantee a labour-friendly construction method with a high laying speed. A good example of this type of method can be seen in laying Silka calcium silicate large format blocks, which are supplied as a complete construction system. These large format blocks are drawn out in advance at one of Xella's factories. Based on the working wall drawings produced, fitting pieces are sawn precisely to size and then coded and delivered. On the construction site, the bricklayer can then build the walls in accordance with the working wall drawings. Because the large format blocks weigh between 100 and 300 kg per unit, they are laid using a crane. This requires minimal physical effort and only a small amount of electrical power. Using a double clamping device, it is even possible to position two large format blocks at the same time. This makes building an unanchored cavity wall even quicker.
