Flat Slab Structural System 

Although this structural system is very established for reinforced concrete system, there are very few buildings in Sarawak adopting this system. The main reason is the traditional belief of using beam-slab system being the safest, easier to design and better feng-sui. Of course, more materials, such as concrete and reinforcements, are required for the flat slab system which also discourage the engineers/owners to use the system. The layout and shape of the building will also determine the feasibility of using the system, for example, squarish and rectangular shapes favour such structural system.

This 10 storey L-shaped  Building in Bintulu with one basement, was one of the very first building to adopt flat slab system. 

It also took a lot of efforts to convince the Owner of using the system with the following advantages:

(a) Easier and faster to build
There would be less formwork and easier to lay steel reinforcements. While beam slab system would require one month to build each floor at that time, the flat slab system would require only two weeks.

(b) Easier to instal Mechanical and Electrical services
Without beams protrusion, M & E services could be laid easily.

(c) Offset cost and save time
The higher cost of more materials would be off-set by saving labour works, waiting time and overheads. Furthermore, shorter construction time will be required means faster economic return.

(d) Can build additional floor
Most building height is restricted by town planner in a particular area. Floor to floor height is also determined by the clear height requirement of the building by-law. Flat slab system reduces the space for structural system, enabling saving of 300mm space for each floor. Thus for 10 storeys, about 3m height of space could be saved and additional floor could be provided with the approval of the local authorities.

The Owner was at first sceptical and he approved only the lower four commercial floors for flat slab system while the upper floors to maintain the beam-slab system.

However, after constructing two floors, he found the speed of construction, safe indeed, cost off-set and other advantages, he requested to change all upper floors to flat slab system!

Later, the upper floors were changed from apartments to hotel with swimming pool. Such changes resulted some additional steel plate reinforcements on the flat slab which were also quite easy to construct.

The building has been there for twenty-seven years and proves that flat slab system can be a good alternative structural system.