O’Brien Sand and cement is a dried sand and cement product that is pre-mixed and blended. The pre-mixed ratio is approximately 3 parts sand to 1 part cement using the traditional volume method or 4 parts sand to 1 part cement using the weight method. The individual constituents of this mix meet Irish and European standards for building products. The cement used is O’Brien cement manufactured in Ireland certified to IS EN 197-1 2011.