A formwork system includes a height-adjustable support for supporting a beam in substantially horizontal or slightly inclined position that includes a support with a central upstanding member and a support arm. The support arm has a rounded socket, and the beam has a cylindrical mounting pin proximate its end. The socket and mounting pin are shaped and sized so that the mounting pin is retained within the socket and they together form a hinge joint. As the mounting pin is retained by the socket of the support arm, it does not shift laterally relative to the support arm as the support arm is vertically adjusted. The variance in the gap between laterally secured forming panels as a response to vertical shift of the support is dependent on the incline angle of the beam and the dimensions of the beam and the support arm. This is predictable within a defined tolerance.