The flooring can be of timber or chipboard floor boards supported by either timber joists or steel joists system. Promat boards can be directly fixed onto these joists or fixed to a suspended exposed or concealed metal grid system.

This type of ceiling should normally be tested or assessed in accordance with BS 476: Part 21: 1987 and/or AS 1530: Part 4: 2005 and are required to satisfy the three failure criteria of loadbearing capacity (structural adequacy), integrity and insulation.