Building materials

History Roman concrete

The Romans made a strong concrete by mixing lime, water and a volcanic ash called pozzolana with chunks of stone or broken brick. It could be poured into wooden frames to make walls, vaults and domes, and some mixtures even set underwater, which helped in building harbors. The Pantheon's great dome is made of Roman concrete.

Concrete walls were usually faced with brick or stone. One pattern, called opus reticulatum, used small square stones set diagonally like a net.

History Brick and tile

Fired clay bricks were made in large numbers. Many bricks were stamped by the workshop that made them, and these stamps help archaeologists date buildings. Roofs were covered with flat clay tiles (tegulae) with curved tiles (imbrices) over the joints to keep out rain.

History Stone and marble

Builders used local stone such as travertine, a hard pale limestone used for much of the Colosseum, and tuff, a softer volcanic stone. For the grandest buildings they used marble, white from Luna (modern Carrara) in Italy and colored marbles shipped from Greece, Egypt and North Africa. The writer Suetonius reported that Augustus boasted he had found Rome a city of brick and left it a city of marble.

The Roman architect Vitruvius wrote about choosing and preparing building materials, from sand and lime to timber.

Think about it

1. Which of these materials could be found nearby, and which would need to be carried far?
2. Why might it matter that Roman concrete could set underwater?
3. What materials are buildings near you made from?

Key words

Pozzolana

Volcanic ash used in Roman concrete.

Travertine

A hard, pale limestone.

Imbrex

A curved roof tile (plural imbrices).