Abstract: The invention concerns a device comprising a profiled section A made of plastic material with a base plate (2) whereof the reverse side is equipped with means for adhesive fixing (3) against a wall and the face is provided with elastically deformable wings defining in pairs longitudinal troughs (5) with C-shaped cross-section, arranged projecting and transversely spaced apart from one another, at least one of the wings of each trough being integral with the base plate and made of the same semirigid material. The base plate (2) is divided into sections by cleavable or precut transverse lines, coincident with transverse grooves (21) provided in the trough (5), to form in the profiled section independent laying supports. A finish profiled section made of plastic material B provided with snap-on fixing means on the trough (5), is longitudinally cleavable to cover one or several laying supports and the associated pipes (6).