Bathroom cement floor tile: geometric pattern
DHAR by Denis Colomb
Cement tiles are made of several layers of fine mortar comprising Portland cement, that is to say, a mixture of sand, marble powder, cement, and in the decorative layer, of coloured metal oxides. After a chemical hydration reaction, the cement becomes very solid and hard, almost as hard as the initial rocks from which the constituents were extracted. These are the particulars that go into the making of cement tiles. The mould used is made up of a sheet of steel polished flat, onto which is mounted a frame of heavy steel that opens and shuts thanks to a tightening device. The entire apparatus weighs nearly 15 kilos. The bottom plate is first greased. Then onto it is poured, with a spoon or funnel, a mortar of fine consistency a few centimeters thick. The mixture consists of white cement and marble powder, coloured with ochres and metal oxides in powder form. It has a liquid consistency so as to avoid bubbles and other defects. When decoration is wanted, first a divider is placed on the mould. This is a kind of stencil consisting of vertical partitions dividing the surface into compartments corresponding to the colour pattern. Formerly the device was made of foundry bronze. But due to high costs, tin-soldered brass dividers are used today.