OAR 690-210-0350: Resumption of Construction Following Placement of Cement Grout

The time needed for the final set of a cement grout mixture varies greatly in accordance with cement-water ratio and temperature. When cement grout is used to seal a well, construction should not resume until after the final set of the cement grout mixture. Performance of all cement grout seals shall be the responsibility of the person responsible for the construction of the well. Under no circumstances shall construction resume within six hours of the placement of the cement grout seal. Recommended periods of time for the final set are: (1) If Portland Cement is used — 72 hours; (2) If High Early Strength Type III Portland Cement is used — 48 hours; (3) If High-alumina Cement is used — 6 hours.