Polyguard Products is a manufacturer of pipeline coatings since 1953. The Polymeric Mesh Backed Polyguard RD-6 coating has been used in the North American market since 1988 and occupies a very significant part of the American and Canadian girth weld and rehabilitation market share, especially in the shale production areas. Polyguard RD-6 coating is a one layer, simple and very fast to apply. It is differentiated from other multi-layer tape systems in materials, adhesion and application. In addition, it is recognized to be a non-shielding coating system. Non-shielding means that if the coating fails or disbond, cathodic protection current can still protect the steel against corrosion under disbonded coating. The topic of our paper consists of technical explanation & clarification concerning the non-shielding property of Polymeric Mesh Backed Coating (like Polyguard RD-6). Our paper is also illustrating the different ways to test on the field and in laboratories this non-shielding property.