Construction of any roof slab comprises of these following steps..
1.Staging:-After completion of Columns upto Roof Beam Bottom Construction of Roof Slab is stats. The First stage is Staging. Staging is noting but erection of staging forms on which shuttering of Roof Slab or Beam will rest. Staging can be made of different type of materials starting wooden to metal parts, which hold is shuttering. Staging should be stable and firm to hold the load of the slab.It should be firm enough so that during concreting it should properly hold the concrete & shuttering so that shuttering do not bulge of settle.
2.Shuttering:- Shuttering is started after completion of staging. Plywood or metal any type of shuttering are used base on the load of slab. During shuttering proper alignment and level of shuttering is checked. Shuttering is properly sealed to avoid slurry lickage which will lead to honeycomb structure or segregation of concrete. Demolding agent are used in shuttering for smooth finishing of concrete surfaces and easy stripping of shuttering boards.
3. Reinforcement:- Reinforcement the third step is construction of roof slab. It can be started after completion of shuttering or it can be done together with shuttering for beams also. Reinforcement placement to be properly checked according to the BBS or Approved Bad Bending Schedule. Diameter of rods, length, spacing, lap length, no of chairs and location of rods to be properly checked before concreting.
4.Concreting:- After completion of Shuttering, Reinforcement Concreting of Slab is started. Concreting is to be properly done as per design with proper vibration (Surface & Needle Vibrator) for avoiding segregation. Extra care to be given for maintaining proper slump during concreting. No bleeding and creep should be there. After concreting Surface of Slab is finished by manual or mechanical means.
5. Curing:- Curing to be done by making ponds/ carry over the slab. Slab to be cured for 21 days.
6. De-shuttering:- De-shuttering is to be done after slab reaches its design strength ie. after 21 days. If quick setting cement or admixture is used during concreting shuttering can be removed earlier as per the specification of the chemical.
