Transoms are special reinforced elements of gas-concrete for a wide use in construction work.
Most usually transoms are used as light bridging elements over ports and windows, as well as to bridge other openings in walls.
The montage is easy, speeding up the usual proces of bridging by pouring concrete into over window and overport plating.
Transoms are made to span 2.5 m, but leaning-on length must be taken into account ( 20 cm on each side).