Where voids are formed by elevating ground floors slabs the voids are to be ventilated, preferably by natural ventilation means with sufficient openings evenly distributed around the perimeter of the building and any internal dividing walls.
If sufficient ventilation can not be provided mechanical fans may be used subject to approval by Facilities management.
Ground seepage and moisture accumulation on the ground should be minimised by the inclusion of spoon drains, subsurface and agricultural drains to the perimeter of the building to collect and divert any water away from the subfloor void.
Pipes, ducts, switchgear, insulation, and any mechanical equipment located in the underfloor void must be protected against high humidity.
Access must be provided to the underfloor space.