Sunk slabs are slabs which are casted a certain depth (200 or 300 mm or any other depending on design) below normal floor level. This extra depth is used for placing pipes and utility ducts.
Uses of Sunken Slab:
The sunken slab is used in room, toilet, latrine, and wash area floor and within the sunken portion, the floor trap and the drainage lines can be taken. In porch slabs, beams are inverted so a plain surface is available and the beams do not protrude downside.
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