The roof slab is the biggest single day of work on a house. A good slab day is decided the day before.
The Day Before
Formwork
- Level and to the right height; camber if the engineer specifies
- Joints tight so slurry does not leak
- Props plumb, braced, on firm base, at proper spacing
- Release agent applied (not on the steel)
Steel
- Bar sizes and spacing match the slab drawing
- Top bars over beams, supported on chairs
- Laps at correct length and staggered
- Cover blocks under bottom bars, tied in
- Beam stirrups and column starter bars in place
Embedded items
- Electrical conduits and boxes fixed and taped
- Sleeves for pipes, fan hooks, any openings
- Nothing reducing cover or cutting main bars
Materials and people
- Cement for the full pour on site (or RMC confirmed), plus spare
- Sand and aggregate stocked; water supply sufficient
- Mixer, vibrators (plus standby), fuel, lighting
- Enough labour for a continuous pour
- Cube moulds and slump cone ready
- Weather checked — no heavy rain forecast; plan an early start in summer
During the Pour
- Slump test on the first batches; no extra water added
- Pour continuously, working from one end
- Vibrate thoroughly, especially at beam–column junctions
- Walk on planks, not on the top steel
- Keep cover blocks and chairs in place
- Take cube samples as per IS 456 frequency
- Finish surface to level and slope
After the Pour
- Protect from sun and wind; start curing within hours
- Build bunds and pond water for 10–14 days
- Keep heavy material off the young slab
- Strip soffit forms and props only after IS 456 minimum times
- Record cube results at 7 and 28 days
The Short Version
Check formwork, steel and embedded items the day before; have every material and person ready; pour continuously with vibration and testing; then cure for two weeks and respect prop times.
