Cover blocks in place — 50 mm to footing reinforcement
Applies only if your house has an RCC spread footing foundation.
Cover is the only thing between your steel and the water in the ground. Too little and the bars rust, swell and split the concrete from inside; you will not see it for years and cannot fix it when you do.
What to look at
- Blocks at close enough spacing that the mesh does not sag between them
- Cover on the SIDES of the footing as well as the bottom
- Block thickness measured, not eyeballed
How to check it yourself
Cover blocks of the correct thickness are tied under and beside the reinforcement before the pour, not pushed in afterwards. IS 456 sets 50 mm as the minimum cover — the thickness of concrete between the steel and the outside face for footings. Near the Kerala coast the exposure is severe or very severe and the design may call for more — read the structural drawing rather than assuming the minimum.
Where this comes from: IS 456:2000 cl. 26.4.2.2 (footings, 50 mm); Table 16 (cover by exposure condition) (indian standard or building code)
More foundation checks
- Photograph before this is covered
- 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
- Raft foundation: reinforcement laid in the order the drawing gives and not walked flat
- 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