flitch

compound beam , typically made up of steel plate(s) sandwiched between wood beams

pros :

each steel plate can replace timber 20 times thicker, due to relative elasticity of the two materials
resulting in greatly reduced overall thickness

easier to lift and assemble in situ compared to homogenous equivalent

can be fastened economically using nails or timber screws

combines strength of steel with aesthetics of timber


cons :

requires care connecting components properly