The cover to reinforcement is a critical parameter to ensure the durability of reinforced concrete structures. This paper presents a brief review of measuring principles, common terminology, and measuring devices for cover to reinforcement. A series of comparative tests is presented on cover depth using commercially available covermeters, carried out by RILEM TC 189-NEC (Non Destructive Evaluation of the Penetrability and Thickness of the Concrete Cover). These comparative tests are summarized to identify the reliability of common cover measuring devices for use in implementing quality control checks for new construction. The variability of cover depths is quantified for real structures and analysed for both international and South African cover survey data. Based on these analyses, shortcomings in the specifications and control of cover depths are discussed, identifying the need for more stringent design procedures and the application of quality control measures for new construction.