a method for producing a cable including at least one transmissive element , for example , an element transmitting electrical energy or optionally optical signals as well , and an expanded and cross - linked coating layer in a radially outer position with respect to the at least one transmissive element , the coating layer having a composition including an expandable and cross - linkable polymeric material . the method includes a ) extruding the composition ; b ) forming a coating layer made of expandable and cross - linkable polymeric material with the composition thus extruded ; c ) expanding the coating layer made of expandable and cross - linkable polymeric material ; and d ) cross - linking the coating layer made of expandable and cross - linkable polymeric material . the expanding and cross - linking steps c ) and d ) are carried out by heating the coating layer made of expandable and cross - linkable polymeric material at atmospheric pressure by means of a suitable heating fluid . savings in production time and costs are attained by the method .