A beam for scaffold platforms for forming a scaffold platform plane, comprising at least two profiles which are guided longitudinally displaceably in one another and have recesses which, in the overlapping region, form openings for the reception of scaffold platforms, wherein the shape and/or the size of the openings is variable by longitudinal displacement of the profiles relative to one another.

A scaffold platform plane, a method for building a scaffold platform plane and the use of a beam.

Anti-lift system for a floor part for a scaffold, comprising: an end piece provided with one or more hook elements with which the floor part can be hooked to a transverse ledger of the scaffold so as to be supported on that transverse ledger, wherein the hook elements define a ledger receiving space for the transverse ledger; and a stiff bolt couplable with the end piece, which in coupled condition is movable relative to the end piece along a bolt movement path between a releasing position and a locking position, wherein the bolt in the locking position extends along the ledger receiving space to block movement of a received transverse ledger out of the ledger receiving space, wherein the bolt in the releasing position extends less or not along the ledger receiving space to release movement of the received transverse ledger out of the ledger receiving space. The system is configured to have the bolt automatically move to the locking position when the bolt is between the locking position and the releasing position. A resistance element can stabilize the releasing position.