Patent ID: 6951435

Claim:
A method of forming a detectable warning surface, comprising: a) providing an unhardened, hardenable, semi-solid material on a surface; b) providing a tool for forming a surface, the tool including: i) a stamp; ii) a forming element provided on the stamp, the forming element including an interior and an exterior, the interior including a forming surface configured for forming a semi-solid material into a predetermined shape; and iii) a pressure-relief element provided adjacent the forming element, the pressure-relief element being sized and configured for causing air to enter and exit the interior of the forming element, in use, so that the predetermined shape is obtained when the stamp is used and the forming element is forming a semi-solid material into the predetermined shape; c) the pressure-relief element including a hole provided in the stamp, the hole extending between the interior and the exterior; d) the predetermined shape including a truncated conical section; e) pressing the forming tool sufficiently into the unhardened semi-solid material so that the forming element forms the semi-solid material into the predetermined shape; and f) pressing the forming tool sufficiently into the unhardened semi-solid material so that excess unhardened semi-solid material extends through the hole of the pressure-relief element.