This part of ISO 10465 presents a comparison of the ATV and AWWA methods for static calculations on underground GRP pipe installations. It is intended that this comparison will encourage the use of both procedures for GRP pipes conforming to International Standards. It is not the intent of this part of ISO 10465 to cover all the details of the two methods. Some aspects are, of necessity, very complex, and for a full understanding the original documents need to be studied in detail. Rather, the intention is to give a general overview and comparison of the key elements so that the user can more easily understand and appreciate the differences between the two procedures and their similarities.