Extract

Roman building practice was everywhere based on locally available materials. The only building materials widely transported in the Roman empire were *marble and *timber for roofing. In Rome itself the plentiful local supplies of soft, easily dressed, volcanic tufa were used from the 6th cent. bce onwards and remained in use at all periods as a general-purpose building material (see quarries). From the 2nd cent. bce travertine was quarried near *Tibur. This was a fine building stone, used particularly in the later republic for architectural decoration; it continued to be used in the imperial period, e.g. for the facades of the Theatre of Marcellus and the *Colosseum. For much domestic architecture the use of timber-framed unfired brick (see brickstamps, roman) was widespread in Rome before the fire of ce 64. The major Roman contribution to architectural development was the exploitation and perfection of opus caementicium, Roman concrete.