The invention relates to a device for holding a levelling strip (14) on a carriage for applying cold laid coatings, wherein said strip extends in a direction that is generally perpendicular to the direction of movement of the carriage, characterised in that said carriage comprises on the rear side opposite to the direction of its movement a support frame (12) which has an adjustable length so that it can adapt to the width of the application zone of the coating and which supports a levelling strip (14), made from a flexible and slightly elastic material, of which one first free end (16) is attached to a first free external edge of the support frame (18) and in that the second free external edge (20), that is opposite the first, of the support frame comprises a vertical axis breast roller (22) on which the levelling strip (14) is tensioned by means of a winding device (24) that applies to said strip a suitable tension while permitting the continuous adjustment of the working length of said strip.