Information to provide in scheme design:

●     Statement that the design is a one way ribbed slab

●     Thickness of topping on top of slab

●     Depth of ribs, which are small downstand beams, and distance from center to center

●     Size of flat beams

●     Clear floor height

Reasons to use this slab type:

Capabilities

●     Aesthetically pleasing due to regular patterns induced by ribbed slab and ceiling shape on the underside

●     Accommodates for floor penetrations, service installations, and high headrooms in one direction

●     Decreases the overall self weight of slabs, but at the same time, has strength and stiffness to limit deflection

●     Provides robustness

●     Standardized fabric glass formworks or lightweight formers on formworks can be used to decrease construction time and effort

●     Parallel spans can accommodate for good service routing arrangements

●     Appropriate for long spans

Disadvantages:

●     Difficult to design and construct partition walls underneath ribbed slabs

●     Difficult to detail and position reinforcements in ribbed slabs

●     Not suitable for heavy and concentrated loads due to small shear capacity of ribs

●     Difficult to construct structures with irregular shapes

●     More finishes work required for large surface area of the structure

●     Service penetrations through ribbed beams decreases beam strength and will lead to reinforcement congestion

●     Long construction time for formwork construction due to void formers

Standard formwork used is expensive for low-rise structures