In an international project, the bill of quantities stipulates that white cement should be used for mosaic jointing in the toilet, but the technical specifications indicate that ordinary Portland cement is used for this work, and ordinary portland cement is also marked on the drawings. During the construction, the owner and the contractor have a dispute on what kind of cement is used to point the joint.

The Owner considers that the use of white cement jointing meets the aesthetic requirements, so the Contractor shall do the work at the unit price in the Bill of Quantities.

The contractor, taking into account the cost of the project and in accordance with Clause1.5, specifies that the technical specifications and drawings restrict the description in the bill of quantities, and therefore shall be constructed in accordance with the requirements of the priority order: the use of ordinary portland cement is a normal performance.

Required:

what should engineers do?