The present invention relates to a joint compound composition for building elements, particularly paper-faced plasterboards.This composition comprises: a) 50 to 60% of calcium sulphate hemihydrate; b) 5 to 15% of an organic binder in powder form; and c) 0.05 to 0.2% of a water repellent. The invention also relates to a method producing a structure, such as a partition, a wall trim or a ceiling.According to this method: building elements are juxtaposed; the joint compound composition according to the invention is mixed with water so as to obtain a joint compound; the space between the building elements is filled by means of the joint compound obtained above, without using a tape; and the joint compound is left to harden.