What is the advantage of hidden beams in a flat slab?

What is the advantage of hidden beams in a flat slab?

Advantage of hidden beams

 Hidden beams’ (or flush beam) primary advantage over dropped beams is that it reduces the minimum floor to floor height required ( for the same clear height below the ceiling and above the floor level). This can generate significant cost savings.

This is especially important in buildings where there are many mechanical/electrical services (HVAC ducts, chilled water pipes, sewage pipes, fire fighting/drinking water supply pipes, electrical cable trays etc.) running horizontally in the ceiling void. Many of these services can pass through dropped beams without weakening the beam. But some items such as HVAC ducts and cable trays cannot, and they will have to routed beneath the bottom of the beam increasing or deepening the ceiling void. Increasing the ceiling void reduces the clear height (minimum in many jurisdictions is 2400 mm) required between the bottom of ceiling finish and the top of the floor finish. To compensate for this loss the total floor to floor height has to be increased, which can increase the costs significantly, especially in multi-storeyed buildings.

This is where hidden beams become advantageous, as the beam is within the slab and will not block any of the services running along its soffit. So, to answer your question, hidden beams solve many practical construction challenges posed by a drop beam, but the primary advantage would be the cost savings achieved through reduced floor to floor height (i.e. fewer quantities of wall, column, glazing, conduiting and piping material required).