Raft foundation: reinforcement laid in the order the drawing gives and not walked flat
Applies only if your house has a raft foundation.
Why — act while you have leverage
A raft carries the whole house on one slab. Its top steel matters as much as its bottom, and top steel trodden down during the pour is a raft that behaves like a thinner one.
What to look at
- Chairs at close enough spacing that the top layer of steel does not dip
- Boards or platforms for the pouring crew to stand on
- Cover re-checked immediately before concrete goes in, not only at tying
How to check it yourself
Chairs hold the top layer of steel at its designed height and stay in place through the pour. Walk boards, not the steel. Check cover at the top as well as the bottom, and check it again after the crew has been across it.
Where this comes from: IS 2950 (Part 1):1981 — Design and construction of raft foundations; IS 456:2000 for cover and curing (indian standard or building code)
More foundation checks
- Photograph before this is covered
- Cover blocks in place — 50 mm to footing reinforcement
- Steel matches the grade and diameter on the drawing
- Concrete cured for at least seven days
- Rubble foundation: through bond stones at every course band
- Rubble foundation: hearting solid, chips under a fifth of the volume
- RCC footing: size and depth as designed, on the correct stratum
- Pile foundation: pile records kept for every pile, not a sample
- Under-reamed piles: bulb formed at the designed depth
- Plinth beam continuous and tied into the foundation
- Column starter bars plumb, with 40 mm cover and correct laps
- Backfill compacted in layers, not tipped in
- Damp proof course laid unbroken at plinth level