The present invention discloses a method and a forming system that reduces the hydrostatic pressure caused by casting freshly mixed concrete or other cementicious material into a vertical form. Reducing the hydrostatic pressure in forms enables relatively weak materials to be used as forms and minimizes the amount of bracing necessary to support the forms—both of which lead to lower construction costs. The method uses the highly thixotropic properties of no-slump or low-slump concrete which enable the concrete to be quickly changed from a semi-solid state to a liquid state and back to a semi-solid state numerous times before it hardens and without affecting the concrete's quality. Since hydrostatic pressure is only present when a liquid state exists, minimizing the amount of liquid concrete in vertical forms will also minimize the hydrostatic pressure present.