Abstract: A height-compensating construction shim has a one-piece plate having opposite parallel upper and lower faces and is formed with a wedge-shaped end having angled surfaces, a longitudinal slot subdividing the plate at the end into a pair of longitudinally extending arms, and rows of transverse elastic retaining tabs projecting toward each other in the slot from inner edges of the arms. An outwardly open bevel is formed on each arm inner edge at an outer end of each arm and longitudinal guide ridges are provided on the angled web surfaces. Interfitting and complementary longitudinally extending guide formations on the upper and lower faces are constructed such that the guide formations of an upper face of one such shim can fit with and slide in the guide formations of a lower face of another such shim. Outwardly open recesses in the upper and lower faces are each formed with a longitudinally extending web.