Abstract: The outer sides of the widened top embankment part of the gutter are provided with small integral continuous longitudinal channels that face upwards and into which the terminal edge of the waterproof facing of the concrete structure fitted with a drainage channel formed by the gutters in question can be correctly abutted so as to form a leaktight joint between the facing and the gutters laid one after the other and such that the water discharged by the facing into the supplementary channels can also be carried away. The ends and middle part of the gutter are also suitably shaped so that the gutter can be joined to other similar gutters, whether these be whole modules or modules cut into sections of the desired length.

Abstract: A modular assembly of channel sections (2) is disclosed which are connected to one another for providing a drainage system by a shutter coupling between a groove 24 formed at one end of any channel section and a rib (6') formed at the other end. Channel section (2) has a modular construction as it is provided with a number of parallel ribs (6') extending in a plane perpendicular to the length of the section at regular intervals so that the length of the final assembled channel can be changed by varying the coupling of the sections. Further anchoring ribs (6) are provided near ribs (6'). A shutter head member (26) coupled at either end of channel section (2) and having a dead but easily pierceable pipe fitting (30) is also provided.