A method in which a stream of dry cementitious powder from a dry powder feeder passes through a dry cementitious powder inlet conduit to feed a first feed section of a fiber-slurry mixer. An aqueous medium stream passes through at least one aqueous medium stream conduit to feed a first mixing section the fiber-slurry mixer. A stream of reinforcing fibers passes from a fiber feeder through a reinforcing fibers stream conduit to feed a second mixing section of the fiber-slurry mixer. The stream of dry cementitious powder, aqueous medium stream, and stream of reinforcing fibers combine in the fiber-slurry mixer to make a stream of fiber-cement mixture which discharges through a discharge conduit at a downstream end of the mixer.